diff options
Diffstat (limited to 'test/ruby/example.in.rb')
| -rw-r--r-- | test/ruby/example.in.rb | 6281 |
1 files changed, 0 insertions, 6281 deletions
diff --git a/test/ruby/example.in.rb b/test/ruby/example.in.rb index c89d3ab..8e6d20e 100644 --- a/test/ruby/example.in.rb +++ b/test/ruby/example.in.rb @@ -3786,6285 +3786,4 @@ if $0 == __FILE__ break if c.typ == TokenConsts::EOP
end
end
-# -*- ruby -*-
-
-# Local variables:
-# indent-tabs-mode: nil
-# ruby-indent-level: 4
-# End:
-
-# @@PLEAC@@_NAME
-# @@SKIP@@ Ruby
-
-# @@PLEAC@@_WEB
-# @@SKIP@@ http://www.ruby-lang.org
-
-
-# @@PLEAC@@_1.0
-string = '\n' # two characters, \ and an n
-string = 'Jon \'Maddog\' Orwant' # literal single quotes
-
-string = "\n" # a "newline" character
-string = "Jon \"Maddog\" Orwant" # literal double quotes
-
-string = %q/Jon 'Maddog' Orwant/ # literal single quotes
-
-string = %q[Jon 'Maddog' Orwant] # literal single quotes
-string = %q{Jon 'Maddog' Orwant} # literal single quotes
-string = %q(Jon 'Maddog' Orwant) # literal single quotes
-string = %q<Jon 'Maddog' Orwant> # literal single quotes
-
-a = <<"EOF"
-This is a multiline here document
-terminated by EOF on a line by itself
-EOF
-
-
-# @@PLEAC@@_1.1
-value = string[offset,count]
-value = string[offset..-1]
-
-string[offset,count] = newstring
-string[offset..-1] = newtail
-
-# in Ruby we can also specify intervals by their two offsets
-value = string[offset..offs2]
-string[offset..offs2] = newstring
-
-leading, s1, s2, trailing = data.unpack("A5 x3 A8 A8 A*")
-
-fivers = string.unpack("A5" * (string.length/5))
-
-chars = string.unpack("A1" * string.length)
-
-string = "This is what you have"
-# +012345678901234567890 Indexing forwards (left to right)
-# 109876543210987654321- Indexing backwards (right to left)
-# note that 0 means 10 or 20, etc. above
-
-first = string[0, 1] # "T"
-start = string[5, 2] # "is"
-rest = string[13..-1] # "you have"
-last = string[-1, 1] # "e"
-end_ = string[-4..-1] # "have"
-piece = string[-8, 3] # "you"
-
-string[5, 2] = "wasn't" # change "is" to "wasn't"
-string[-12..-1] = "ondrous" # "This wasn't wondrous"
-string[0, 1] = "" # delete first character
-string[-10..-1] = "" # delete last 10 characters
-
-if string[-10..-1] =~ /pattern/
- puts "Pattern matches in last 10 characters"
-end
-
-string[0, 5].gsub!(/is/, 'at')
-
-a = "make a hat"
-a[0, 1], a[-1, 1] = a[-1, 1], a[0, 1]
-
-a = "To be or not to be"
-b = a.unpack("x6 A6")
-
-b, c = a.unpack("x6 A2 X5 A2")
-puts "#{b}\n#{c}\n"
-
-def cut2fmt(*args)
- template = ''
- lastpos = 1
- for place in args
- template += "A" + (place - lastpos).to_s + " "
- lastpos = place
- end
- template += "A*"
- return template
-end
-
-fmt = cut2fmt(8, 14, 20, 26, 30)
-
-
-# @@PLEAC@@_1.2
-# careful! "b is true" doesn't mean "b != 0" (0 is true in Ruby)
-# thus no problem of "defined" later since only nil is false
-# the following sets to `c' if `b' is nil or false
-a = b || c
-
-# if you need Perl's behaviour (setting to `c' if `b' is 0) the most
-# effective way is to use Numeric#nonzero? (thanks to Dave Thomas!)
-a = b.nonzero? || c
-
-# you will still want to use defined? in order to test
-# for scope existence of a given object
-a = defined?(b) ? b : c
-
-dir = ARGV.shift || "/tmp"
-
-
-# @@PLEAC@@_1.3
-v1, v2 = v2, v1
-
-alpha, beta, production = %w(January March August)
-alpha, beta, production = beta, production, alpha
-
-
-# @@PLEAC@@_1.4
-num = char[0]
-char = num.chr
-
-# Ruby also supports having a char from character constant
-num = ?r
-
-char = sprintf("%c", num)
-printf("Number %d is character %c\n", num, num)
-
-ascii = string.unpack("C*")
-string = ascii.pack("C*")
-
-hal = "HAL"
-ascii = hal.unpack("C*")
-# We can't use Array#each since we can't mutate a Fixnum
-ascii.collect! { |i|
- i + 1 # add one to each ASCII value
-}
-ibm = ascii.pack("C*")
-puts ibm
-
-
-# @@PLEAC@@_1.5
-array = string.split('')
-
-array = string.unpack("C*")
-
-string.scan(/./) { |b|
- # do something with b
-}
-
-string = "an apple a day"
-print "unique chars are: ", string.split('').uniq.sort, "\n"
-
-sum = 0
-for ascval in string.unpack("C*") # or use Array#each for a pure OO style :)
- sum += ascval
-end
-puts "sum is #{sum & 0xffffffff}" # since Ruby will go Bignum if necessary
-
-# @@INCLUDE@@ include/ruby/slowcat.rb
-
-
-# @@PLEAC@@_1.6
-revbytes = string.reverse
-
-revwords = string.split(" ").reverse.join(" ")
-
-revwords = string.split(/(\s+)/).reverse.join
-
-# using the fact that IO is Enumerable, you can directly "select" it
-long_palindromes = File.open("/usr/share/dict/words").
- select { |w| w.chomp!; w.reverse == w && w.length > 5 }
-
-
-# @@PLEAC@@_1.7
-while string.sub!("\t+") { ' ' * ($&.length * 8 - $`.length % 8) }
-end
-
-
-# @@PLEAC@@_1.8
-'You owe #{debt} to me'.gsub(/\#{(\w+)}/) { eval($1) }
-
-rows, cols = 24, 80
-text = %q(I am #{rows} high and #{cols} long)
-text.gsub!(/\#{(\w+)}/) { eval("#{$1}") }
-puts text
-
-'I am 17 years old'.gsub(/\d+/) { 2 * $&.to_i }
-
-
-# @@PLEAC@@_1.9
-e = "bo peep".upcase
-e.downcase!
-e.capitalize!
-
-"thIS is a loNG liNE".gsub!(/\w+/) { $&.capitalize }
-
-
-# @@PLEAC@@_1.10
-"I have #{n+1} guanacos."
-print "I have ", n+1, " guanacos."
-
-
-# @@PLEAC@@_1.11
-var = <<'EOF'.gsub(/^\s+/, '')
- your text
- goes here
-EOF
-
-
-# @@PLEAC@@_1.12
-string = "Folding and splicing is the work of an editor,\n"+
- "not a mere collection of silicon\n"+
- "and\n"+
- "mobile electrons!"
-
-def wrap(str, max_size)
- all = []
- line = ''
- for l in str.split
- if (line+l).length >= max_size
- all.push(line)
- line = ''
- end
- line += line == '' ? l : ' ' + l
- end
- all.push(line).join("\n")
-end
-
-print wrap(string, 20)
-#=> Folding and
-#=> splicing is the
-#=> work of an editor,
-#=> not a mere
-#=> collection of
-#=> silicon and mobile
-#=> electrons!
-
-
-# @@PLEAC@@_1.13
-string = %q(Mom said, "Don't do that.")
-string.gsub(/['"]/) { '\\'+$& }
-string.gsub(/['"]/, '\&\&')
-string.gsub(/[^A-Z]/) { '\\'+$& }
-"is a test!".gsub(/\W/) { '\\'+$& } # no function like quotemeta?
-
-
-# @@PLEAC@@_1.14
-string.strip!
-
-
-# @@PLEAC@@_1.15
-def parse_csv(text)
- new = text.scan(/"([^\"\\]*(?:\\.[^\"\\]*)*)",?|([^,]+),?|,/)
- new << nil if text[-1] == ?,
- new.flatten.compact
-end
-
-line = %q<XYZZY,"","O'Reilly, Inc","Wall, Larry","a \"glug\" bit,",5,"Error, Core Dumped">
-fields = parse_csv(line)
-fields.each_with_index { |v,i|
- print "#{i} : #{v}\n";
-}
-
-
-# @@PLEAC@@_1.16
-# Use the soundex.rb Library from Michael Neumann.
-# http://www.s-direktnet.de/homepages/neumann/rb_prgs/Soundex.rb
-require 'Soundex'
-
-code = Text::Soundex.soundex(string)
-codes = Text::Soundex.soundex(array)
-
-# substitution function for getpwent():
-# returns an array of user entries,
-# each entry contains the username and the full name
-def login_names
- result = []
- File.open("/etc/passwd") { |file|
- file.each_line { |line|
- next if line.match(/^#/)
- cols = line.split(":")
- result.push([cols[0], cols[4]])
- }
- }
- result
-end
-
-puts "Lookup user: "
-user = STDIN.gets
-user.chomp!
-exit unless user
-name_code = Text::Soundex.soundex(user)
-
-splitter = Regexp.new('(\w+)[^,]*\b(\w+)')
-for username, fullname in login_names do
- firstname, lastname = splitter.match(fullname)[1,2]
- if name_code == Text::Soundex.soundex(username)
- || name_code == Text::Soundex.soundex(firstname)
- || name_code == Text::Soundex.soundex(lastname)
- then
- puts "#{username}: #{firstname} #{lastname}"
- end
-end
-
-
-# @@PLEAC@@_1.17
-# @@INCLUDE@@ include/ruby/fixstyle.rb
-
-
-# @@PLEAC@@_1.18
-# @@INCLUDE@@ include/ruby/psgrep.rb
-
-
-# @@PLEAC@@_2.1
-# Matz tells that you can use Integer() for strict checked conversion.
-Integer("abc")
-#=> `Integer': invalid value for Integer: "abc" (ArgumentError)
-Integer("567")
-#=> 567
-
-# You may use Float() for floating point stuff
-Integer("56.7")
-#=> `Integer': invalid value for Integer: "56.7" (ArgumentError)
-Float("56.7")
-#=> 56.7
-
-# You may also use a regexp for that
-if string =~ /^[+-]?\d+$/
- p 'is an integer'
-else
- p 'is not'
-end
-
-if string =~ /^-?(?:\d+(?:\.\d*)?|\.\d+)$/
- p 'is a decimal number'
-else
- p 'is not'
-end
-
-
-# @@PLEAC@@_2.2
-# equal(num1, num2, accuracy) : returns true if num1 and num2 are
-# equal to accuracy number of decimal places
-def equal(i, j, a)
- sprintf("%.#{a}g", i) == sprintf("%.#{a}g", j)
-end
-
-wage = 536 # $5.36/hour
-week = 40 * wage # $214.40
-printf("One week's wage is: \$%.2f\n", week/100.0)
-
-
-# @@PLEAC@@_2.3
-num.round # rounds to integer
-
-a = 0.255
-b = sprintf("%.2f", a)
-print "Unrounded: #{a}\nRounded: #{b}\n"
-printf "Unrounded: #{a}\nRounded: %.2f\n", a
-
-print "number\tint\tfloor\tceil\n"
-a = [ 3.3 , 3.5 , 3.7, -3.3 ]
-for n in a
- printf("% .1f\t% .1f\t% .1f\t% .1f\n", # at least I don't fake my output :)
- n, n.to_i, n.floor, n.ceil)
-end
-
-
-# @@PLEAC@@_2.4
-def dec2bin(n)
- [n].pack("N").unpack("B32")[0].sub(/^0+(?=\d)/, '')
-end
-
-def bin2dec(n)
- [("0"*32+n.to_s)[-32..-1]].pack("B32").unpack("N")[0]
-end
-
-
-# @@PLEAC@@_2.5
-for i in x .. y
- # i is set to every integer from x to y, inclusive
-end
-
-x.step(y,7) { |i|
- # i is set to every integer from x to y, stepsize = 7
-}
-
-print "Infancy is: "
-(0..2).each { |i|
- print i, " "
-}
-print "\n"
-
-
-# @@PLEAC@@_2.6
-# We can add conversion methods to the Integer class,
-# this makes a roman number just a representation for normal numbers.
-class Integer
-
- @@romanlist = [["M", 1000],
- ["CM", 900],
- ["D", 500],
- ["CD", 400],
- ["C", 100],
- ["XC", 90],
- ["L", 50],
- ["XL", 40],
- ["X", 10],
- ["IX", 9],
- ["V", 5],
- ["IV", 4],
- ["I", 1]]
-
- def to_roman
- remains = self
- roman = ""
- for sym, num in @@romanlist
- while remains >= num
- remains -= num
- roman << sym
- end
- end
- roman
- end
-
- def Integer.from_roman(roman)
- ustr = roman.upcase
- sum = 0
- for entry in @@romanlist
- sym, num = entry[0], entry[1]
- while sym == ustr[0, sym.length]
- sum += num
- ustr.slice!(0, sym.length)
- end
- end
- sum
- end
-
-end
-
-
-roman_fifteen = 15.to_roman
-puts "Roman for fifteen is #{roman_fifteen}"
-i = Integer.from_roman(roman_fifteen)
-puts "Converted back, #{roman_fifteen} is #{i}"
-
-# check
-for i in (1..3900)
- r = i.to_roman
- j = Integer.from_roman(r)
- if i != j
- puts "error: #{i} : #{r} - #{j}"
- end
-end
-
-
-# @@PLEAC@@_2.7
-random = rand(y-x+1)+x
-
-chars = ["A".."Z","a".."z","0".."9"].collect { |r| r.to_a }.join + %q(!@$%^&*)
-password = (1..8).collect { chars[rand(chars.size)] }.pack("C*")
-
-
-# @@PLEAC@@_2.8
-srand # uses a combination of the time, the process id, and a sequence number
-srand(val) # for repeatable behaviour
-
-
-# @@PLEAC@@_2.9
-# from the randomr lib:
-# http://raa.ruby-lang.org/project/randomr/
-----> http://raa.ruby-lang.org/project/randomr/
-
-require 'random/mersenne_twister'
-mers = Random::MersenneTwister.new 123456789
-puts mers.rand(0) # 0.550321932544541
-puts mers.rand(10) # 2
-
-# using online sources of random data via the realrand package:
-# http://raa.ruby-lang.org/project/realrand/
-# **Note**
-# The following online services are used in this package:
-# http://www.random.org - source: atmospheric noise
-# http://www.fourmilab.ch/hotbits - source: radioactive decay timings
-# http://random.hd.org - source: entropy from local and network noise
-# Please visit the sites and respect the rules of each service.
-
-require 'random/online'
-
-generator1 = Random::RandomOrg.new
-puts generator1.randbyte(5).join(",")
-puts generator1.randnum(10, 1, 6).join(",") # Roll dice 10 times.
-
-generator2 = Random::FourmiLab.new
-puts generator2.randbyte(5).join(",")
-# randnum is not supported.
-
-generator3 = Random::EntropyPool.new
-puts generator3.randbyte(5).join(",")
-# randnum is not supported.
-
-
-# @@PLEAC@@_2.10
-def gaussian_rand
- begin
- u1 = 2 * rand() - 1
- u2 = 2 * rand() - 1
- w = u1*u1 + u2*u2
- end while (w >= 1)
- w = Math.sqrt((-2*Math.log(w))/w)
- [ u2*w, u1*w ]
-end
-
-mean = 25
-sdev = 2
-salary = gaussian_rand[0] * sdev + mean
-printf("You have been hired at \$%.2f\n", salary)
-
-
-# @@PLEAC@@_2.11
-def deg2rad(d)
- (d/180.0)*Math::PI
-end
-
-def rad2deg(r)
- (r/Math::PI)*180
-end
-
-
-# @@PLEAC@@_2.12
-sin_val = Math.sin(angle)
-cos_val = Math.cos(angle)
-tan_val = Math.tan(angle)
-
-# AFAIK Ruby's Math module doesn't provide acos/asin
-# While we're at it, let's also define missing hyperbolic functions
-module Math
- def Math.asin(x)
- atan2(x, sqrt(1 - x**2))
- end
- def Math.acos(x)
- atan2(sqrt(1 - x**2), x)
- end
- def Math.atan(x)
- atan2(x, 1)
- end
- def Math.sinh(x)
- (exp(x) - exp(-x)) / 2
- end
- def Math.cosh(x)
- (exp(x) + exp(-x)) / 2
- end
- def Math.tanh(x)
- sinh(x) / cosh(x)
- end
-end
-
-# The support for Complex numbers is not built-in
-y = Math.acos(3.7)
-#=> in `sqrt': square root for negative number (ArgumentError)
-
-# There is an implementation of Complex numbers in 'complex.rb' in current
-# Ruby distro, but it doesn't support atan2 with complex args, so it doesn't
-# solve this problem.
-
-
-# @@PLEAC@@_2.13
-log_e = Math.log(val)
-log_10 = Math.log10(val)
-
-def log_base(base, val)
- Math.log(val)/Math.log(base)
-end
-
-answer = log_base(10, 10_000)
-puts "log10(10,000) = #{answer}"
-
-
-# @@PLEAC@@_2.14
-require 'matrix.rb'
-
-a = Matrix[[3, 2, 3], [5, 9, 8]]
-b = Matrix[[4, 7], [9, 3], [8, 1]]
-c = a * b
-
-a.row_size
-a.column_size
-
-c.det
-a.transpose
-
-
-# @@PLEAC@@_2.15
-require 'complex.rb'
-require 'rational.rb'
-
-a = Complex(3, 5) # 3 + 5i
-b = Complex(2, -2) # 2 - 2i
-puts "c = #{a*b}"
-
-c = a * b
-d = 3 + 4*Complex::I
-
-printf "sqrt(#{d}) = %s\n", Math.sqrt(d)
-
-
-# @@PLEAC@@_2.16
-number = hexadecimal.hex
-number = octal.oct
-
-print "Gimme a number in decimal, octal, or hex: "
-num = gets.chomp
-exit unless defined?(num)
-num = num.oct if num =~ /^0/ # does both oct and hex
-printf "%d %x %o\n", num, num, num
-
-print "Enter file permission in octal: "
-permissions = gets.chomp
-raise "Exiting ...\n" unless defined?(permissions)
-puts "The decimal value is #{permissions.oct}"
-
-
-# @@PLEAC@@_2.17
-def commify(n)
- n.to_s =~ /([^\.]*)(\..*)?/
- int, dec = $1.reverse, $2 ? $2 : ""
- while int.gsub!(/(,|\.|^)(\d{3})(\d)/, '\1\2,\3')
- end
- int.reverse + dec
-end
-
-
-# @@PLEAC@@_2.18
-printf "It took %d hour%s\n", time, time == 1 ? "" : "s"
-
-# dunno if an equivalent to Lingua::EN::Inflect exists...
-
-
-# @@PLEAC@@_2.19
-#-----------------------------
-#!/usr/bin/ruby
-# bigfact - calculating prime factors
-def factorize(orig)
- factors = {}
- factors.default = 0 # return 0 instead nil if key not found in hash
- n = orig
- i = 2
- sqi = 4 # square of i
- while sqi <= n do
- while n.modulo(i) == 0 do
- n /= i
- factors[i] += 1
- # puts "Found factor #{i}"
- end
- # we take advantage of the fact that (i +1)**2 = i**2 + 2*i +1
- sqi += 2 * i + 1
- i += 1
- end
-
- if (n != 1) && (n != orig)
- factors[n] += 1
- end
- factors
-end
-
-def printfactorhash(orig, factorcount)
- print format("%-10d ", orig)
- if factorcount.length == 0
- print "PRIME"
- else
- # sorts after number, because the hash keys are numbers
- factorcount.sort.each { |factor,exponent|
- print factor
- if exponent > 1
- print "**", exponent
- end
- print " "
- }
- end
- puts
-end
-
-for arg in ARGV
- n = arg.to_i
- mfactors = factorize(n)
- printfactorhash(n, mfactors)
-end
-#-----------------------------
-
-
-# @@PLEAC@@_3.0
-puts Time.now
-
-print "Today is day ", Time.now.yday, " of the current year.\n"
-print "Today is day ", Time.now.day, " of the current month.\n"
-
-
-# @@PLEAC@@_3.1
-day, month, year = Time.now.day, Time.now.month, Time.now.year
-# or
-day, month, year = Time.now.to_a[3..5]
-
-tl = Time.now.localtime
-printf("The current date is %04d %02d %02d\n", tl.year, tl.month, tl.day)
-
-Time.now.localtime.strftime("%Y-%m-%d")
-
-
-# @@PLEAC@@_3.2
-Time.local(year, month, day, hour, minute, second).tv_sec
-Time.gm(year, month, day, hour, minute, second).tv_sec
-
-
-# @@PLEAC@@_3.3
-sec, min, hour, day, month, year, wday, yday, isdst, zone = Time.at(epoch_secs).to_a
-
-
-# @@PLEAC@@_3.4
-when_ = now + difference # now -> Time ; difference -> Numeric (delta in seconds)
-then_ = now - difference
-
-
-# @@PLEAC@@_3.5
-bree = 361535725
-nat = 96201950
-
-difference = bree - nat
-puts "There were #{difference} seconds between Nat and Bree"
-
-seconds = difference % 60
-difference = (difference - seconds) / 60
-minutes = difference % 60
-difference = (difference - minutes) / 60
-hours = difference % 24
-difference = (difference - hours) / 24
-days = difference % 7
-weeks = (difference - days) / 7
-
-puts "(#{weeks} weeks, #{days} days, #{hours}:#{minutes}:#{seconds})"
-
-
-# @@PLEAC@@_3.6
-monthday, weekday, yearday = date.mday, date.wday, date.yday
-
-# AFAIK the week number is not just a division since week boundaries are on sundays
-weeknum = d.strftime("%U").to_i + 1
-
-year = 1981
-month = "jun" # or `6' if you want to emulate a broken language
-day = 16
-t = Time.mktime(year, month, day)
-print "#{month}/#{day}/#{year} was a ", t.strftime("%A"), "\n"
-
-
-# @@PLEAC@@_3.7
-yyyy, mm, dd = $1, $2, $3 if "1998-06-25" =~ /(\d+)-(\d+)-(\d+)/
-
-epoch_seconds = Time.mktime(yyyy, mm, dd).tv_sec
-
-# dunno an equivalent to Date::Manip#ParseDate
-
-
-# @@PLEAC@@_3.8
-string = Time.at(epoch_secs)
-Time.at(1234567890).gmtime # gives: Fri Feb 13 23:31:30 UTC 2009
-
-time = Time.mktime(1973, "jan", 18, 3, 45, 50)
-print "In localtime it gives: ", time.localtime, "\n"
-
-
-# @@PLEAC@@_3.9
-# Ruby provides micro-seconds in Time object
-Time.now.usec
-
-# Ruby gives the seconds in floating format when substracting two Time objects
-before = Time.now
-line = gets
-elapsed = Time.now - before
-puts "You took #{elapsed} seconds."
-
-# On my Celeron-400 with Linux-2.2.19-14mdk, average for three execs are:
-# This Ruby version: average 0.00321 sec
-# Cookbook's Perl version: average 0.00981 sec
-size = 500
-number_of_times = 100
-total_time = 0
-number_of_times.times {
- # populate array
- array = []
- size.times { array << rand }
- # sort it
- begin_ = Time.now
- array.sort!
- time = Time.now - begin_
- total_time += time
-}
-printf "On average, sorting %d random numbers takes %.5f seconds\n",
- size, (total_time/Float(number_of_times))
-
-
-# @@PLEAC@@_3.10
-sleep(0.005) # Ruby is definitely not as broken as Perl :)
-# (may be interrupted by sending the process a SIGALRM)
-
-
-# @@PLEAC@@_3.11
-#!/usr/bin/ruby -w
-# hopdelta - feed mail header, produce lines
-# showing delay at each hop.
-require 'time'
-class MailHopDelta
-
- def initialize(mail)
- @head = mail.gsub(/\n\s+/,' ')
- @topline = %w-Sender Recipient Time Delta-
- @start_from = mail.match(/^From.*\@([^\s>]*)/)[1]
- @date = Time.parse(mail.match(/^Date:\s+(.*)/)[1])
- end
-
- def out(line)
- "%-20.20s %-20.20s %-20.20s %s" % line
- end
-
- def hop_date(day)
- day.strftime("%I:%M:%S %Y/%m/%d")
- end
-
- def puts_hops
- puts out(@topline)
- puts out(['Start', @start_from, hop_date(@date),''])
- @head.split(/\n/).reverse.grep(/^Received:/).each do |hop|
- hop.gsub!(/\bon (.*?) (id.*)/,'; \1')
- whence = hop.match(/;\s+(.*)$/)[1]
- unless whence
- warn "Bad received line: #{hop}"
- next
- end
- from = $+ if hop =~ /from\s+(\S+)|\((.*?)\)/
- by = $1 if hop =~ /by\s+(\S+\.\S+)/
- next unless now = Time.parse(whence).localtime
- delta = now - @date
- puts out([from, by, hop_date(now), hop_time(delta)])
- @date = now
- end
- end
-
- def hop_time(secs)
- sign = secs < 0 ? -1 : 1
- days, secs = secs.abs.divmod(60 * 60 * 24)
- hours,secs = secs.abs.divmod(60 * 60)
- mins, secs = secs.abs.divmod(60)
- rtn = "%3ds" % [secs * sign]
- rtn << "%3dm" % [mins * sign] if mins != 0
- rtn << "%3dh" % [hours * sign] if hours != 0
- rtn << "%3dd" % [days * sign] if days != 0
- rtn
- end
-end
-
-$/ = ""
-mail = MailHopDelta.new(ARGF.gets).puts_hops
-
-
-# @@PLEAC@@_4.0
-single_level = [ "this", "that", "the", "other" ]
-
-# Ruby directly supports nested arrays
-double_level = [ "this", "that", [ "the", "other" ] ]
-still_single_level = [ "this", "that", [ "the", "other" ] ].flatten
-
-
-# @@PLEAC@@_4.1
-a = [ "quick", "brown", "fox" ]
-a = %w(Why are you teasing me?)
-
-lines = <<"END_OF_HERE_DOC".gsub(/^\s*(.+)/, '\1')
- The boy stood on the burning deck,
- It was as hot as glass.
-END_OF_HERE_DOC
-
-bigarray = IO.readlines("mydatafile").collect { |l| l.chomp }
-
-name = "Gandalf"
-banner = %Q(Speak, #{name}, and welcome!)
-
-host_info = `host #{his_host}`
-
-%x(ps #{$$})
-
-banner = 'Costs only $4.95'.split(' ')
-
-rax = %w! ( ) < > { } [ ] !
-
-
-# @@PLEAC@@_4.2
-def commify_series(a)
- a.size == 0 ? '' :
- a.size == 1 ? a[0] :
- a.size == 2 ? a.join(' and ') :
- a[0..-2].join(', ') + ', and ' + a[-1]
-end
-
-array = [ "red", "yellow", "green" ]
-
-print "I have ", array, " marbles\n"
-# -> I have redyellowgreen marbles
-
-# But unlike Perl:
-print "I have #{array} marbles\n"
-# -> I have redyellowgreen marbles
-# So, needs:
-print "I have #{array.join(' ')} marbles\n"
-# -> I have red yellow green marbles
-
-def commify_series(a)
- sepchar = a.select { |p| p =~ /,/ } != [] ? '; ' : ', '
- a.size == 0 ? '' :
- a.size == 1 ? a[0] :
- a.size == 2 ? a.join(' and ') :
- a[0..-2].join(sepchar) + sepchar + 'and ' + a[-1]
-end
-
-
-# @@PLEAC@@_4.3
-# (note: AFAIK Ruby doesn't allow gory change of Array length)
-# grow the array by assigning nil to past the end of array
-ary[new_size-1] = nil
-# shrink the array by slicing it down
-ary.slice!(new_size..-1)
-# init the array with given size
-Array.new(number_of_elems)
-# assign to an element past the original end enlarges the array
-ary[index_new_last_elem] = value
-
-def what_about_that_array(a)
- print "The array now has ", a.size, " elements.\n"
- # Index of last element is not really interesting in Ruby
- print "Element #3 is `#{a[3]}'.\n"
-end
-people = %w(Crosby Stills Nash Young)
-what_about_that_array(people)
-
-
-# @@PLEAC@@_4.4
-# OO style
-bad_users.each { |user|
- complain(user)
-}
-# or, functional style
-for user in bad_users
- complain(user)
-end
-
-for var in ENV.keys.sort
- puts "#{var}=#{ENV[var]}"
-end
-
-for user in all_users
- disk_space = get_usage(user)
- if (disk_space > MAX_QUOTA)
- complain(user)
- end
-end
-
-for l in IO.popen("who").readlines
- print l if l =~ /^gc/
-end
-
-# we can mimic the obfuscated Perl way
-while fh.gets # $_ is set to the line just read
- chomp # $_ has a trailing \n removed, if it had one
- split.each { |w| # $_ is split on whitespace
- # but $_ is not set to each chunk as in Perl
- print w.reverse
- }
-end
-# ...or use a cleaner way
-for l in fh.readlines
- l.chomp.split.each { |w| print w.reverse }
-end
-
-# same drawback as in problem 1.4, we can't mutate a Numeric...
-array.collect! { |v| v - 1 }
-
-a = [ .5, 3 ]; b = [ 0, 1 ]
-for ary in [ a, b ]
- ary.collect! { |v| v * 7 }
-end
-puts "#{a.join(' ')} #{b.join(' ')}"
-
-# we can mutate Strings, cool; we need a trick for the scalar
-for ary in [ [ scalar ], array, hash.values ]
- ary.each { |v| v.strip! } # String#strip rules :)
-end
-
-
-# @@PLEAC@@_4.5
-# not relevant in Ruby since we have always references
-for item in array
- # do somethingh with item
-end
-
-
-# @@PLEAC@@_4.6
-unique = list.uniq
-
-# generate a list of users logged in, removing duplicates
-users = `who`.collect { |l| l =~ /(\w+)/; $1 }.sort.uniq
-puts("users logged in: #{commify_series(users)}") # see 4.2 for commify_series
-
-
-# @@PLEAC@@_4.7
-a - b
-# [ 1, 1, 2, 2, 3, 3, 3, 4, 5 ] - [ 1, 2, 4 ] -> [3, 5]
-
-
-# @@PLEAC@@_4.8
-union = a | b
-intersection = a & b
-difference = a - b
-
-
-# @@PLEAC@@_4.9
-array1.concat(array2)
-# if you will assign to another object, better use:
-new_ary = array1 + array2
-
-members = [ "Time", "Flies" ]
-initiates = [ "An", "Arrow" ]
-members += initiates
-
-members = [ "Time", "Flies" ]
-initiates = [ "An", "Arrow" ]
-members[2,0] = [ "Like", initiates ].flatten
-
-members[0] = "Fruit"
-members[3,2] = "A", "Banana"
-
-
-# @@PLEAC@@_4.10
-reversed = ary.reverse
-
-ary.reverse_each { |e|
- # do something with e
-}
-
-descending = ary.sort.reverse
-descending = ary.sort { |a,b| b <=> a }
-
-
-# @@PLEAC@@_4.11
-# remove n elements from front of ary (shift n)
-front = ary.slice!(0, n)
-
-# remove n elements from the end of ary (pop n)
-end_ = ary.slice!(-n .. -1)
-
-# let's extend the Array class, to make that useful
-class Array
- def shift2()
- slice!(0 .. 1) # more symetric with pop2...
- end
- def pop2()
- slice!(-2 .. -1)
- end
-end
-
-friends = %w(Peter Paul Mary Jim Tim)
-this, that = friends.shift2
-
-beverages = %w(Dew Jolt Cola Sprite Fresca)
-pair = beverages.pop2
-
-
-# @@PLEAC@@_4.12
-# use Enumerable#detect (or the synonym Enumerable#find)
-highest_eng = employees.detect { |emp| emp.category == 'engineer' }
-
-
-# @@PLEAC@@_4.13
-# use Enumerable#select (or the synonym Enumerable#find_all)
-bigs = nums.select { |i| i > 1_000_000 }
-pigs = users.keys.select { |k| users[k] > 1e7 }
-
-matching = `who`.select { |u| u =~ /^gnat / }
-
-engineers = employees.select { |e| e.position == 'Engineer' }
-
-secondary_assistance = applicants.select { |a|
- a.income >= 26_000 && a.income < 30_000
-}
-
-
-# @@PLEAC@@_4.14
-# normally you would have an array of Numeric (Float or
-# Fixnum or Bignum), so you would use:
-sorted = unsorted.sort
-# if you have strings representing Integers or Floats
-# you may specify another sort method:
-sorted = unsorted.sort { |a,b| a.to_f <=> b.to_f }
-
-# let's use the list of my own PID's
-`ps ux`.split("\n")[1..-1].
- select { |i| i =~ /^#{ENV['USER']}/ }.
- collect { |i| i.split[1] }.
- sort { |a,b| a.to_i <=> b.to_i }.each { |i| puts i }
-puts "Select a process ID to kill:"
-pid = gets.chomp
-raise "Exiting ... \n" unless pid && pid =~ /^\d+$/
-Process.kill('TERM', pid.to_i)
-sleep 2
-Process.kill('KILL', pid.to_i)
-
-descending = unsorted.sort { |a,b| b.to_f <=> a.to_f }
-
-
-# @@PLEAC@@_4.15
-ordered = unordered.sort { |a,b| compare(a,b) }
-
-precomputed = unordered.collect { |e| [compute, e] }
-ordered_precomputed = precomputed.sort { |a,b| a[0] <=> b[0] }
-ordered = ordered_precomputed.collect { |e| e[1] }
-
-ordered = unordered.collect { |e| [compute, e] }.
- sort { |a,b| a[0] <=> b[0] }.
- collect { |e| e[1] }
-
-for employee in employees.sort { |a,b| a.name <=> b.name }
- print employee.name, " earns \$ ", employee.salary, "\n"
-end
-
-# Beware! `0' is true in Ruby.
-# For chaining comparisons, you may use Numeric#nonzero?, which
-# returns num if num is not zero, nil otherwise
-sorted = employees.sort { |a,b| (a.name <=> b.name).nonzero? || b.age <=> a.age }
-
-users = []
-# getpwent is not wrapped in Ruby... let's fallback
-IO.readlines('/etc/passwd').each { |u| users << u.split(':') }
-users.sort! { |a,b| a[0] <=> b[0] }
-for user in users
- puts user[0]
-end
-
-sorted = names.sort { |a,b| a[1, 1] <=> b[1, 1] }
-sorted = strings.sort { |a,b| a.length <=> b.length }
-
-# let's show only the compact version
-ordered = strings.collect { |e| [e.length, e] }.
- sort { |a,b| a[0] <=> b[0] }.
- collect { |e| e[1] }
-
-ordered = strings.collect { |e| [/\d+/.match(e)[0].to_i, e] }.
- sort { |a,b| a[0] <=> b[0] }.
- collect { |e| e[1] }
-
-print `cat /etc/passwd`.collect { |e| [e, e.split(':').indexes(3,2,0)].flatten }.
- sort { |a,b| (a[1] <=> b[1]).nonzero? || (a[2] <=> b[2]).nonzero? || a[3] <=> b[3] }.
- collect { |e| e[0] }
-
-
-# @@PLEAC@@_4.16
-circular.unshift(circular.pop) # the last shall be first
-circular.push(circular.shift) # and vice versa
-
-def grab_and_rotate(l)
- l.push(ret = l.shift)
- ret
-end
-
-processes = [1, 2, 3, 4, 5]
-while (1)
- process = grab_and_rotate(processes)
- puts "Handling process #{process}"
- sleep 1
-end
-
-
-# @@PLEAC@@_4.17
-def fisher_yates_shuffle(a)
- (a.size-1).downto(1) { |i|
- j = rand(i+1)
- a[i], a[j] = a[j], a[i] if i != j
- }
-end
-
-def naive_shuffle(a)
- for i in 0...a.size
- j = rand(a.size)
- a[i], a[j] = a[j], a[i]
- end
-end
-
-
-# @@PLEAC@@_4.18
-#!/usr/bin/env ruby
-# example 4-2 words
-# words - gather lines, present in colums
-
-# class to encapsulate the word formatting from the input
-class WordFormatter
- def initialize(cols)
- @cols = cols
- end
-
- # helper to return the length of the longest word in the wordlist
- def maxlen(wordlist)
- max = 1
- for word in wordlist
- if word.length > max
- max = word.length
- end
- end
- max
- end
-
- # process the wordlist and print it formmated into columns
- def output(wordlist)
- collen = maxlen(wordlist) + 1
- columns = @cols / collen
- columns = 1 if columns == 0
- rows = (wordlist.length + columns - 1) / columns
- # now process each item, picking out proper piece for this position
- 0.upto(rows * columns - 1) { |item|
- target = (item % columns) * rows + (item / columns)
- eol = ((item+1) % columns == 0)
- piece = wordlist[target] || ""
- piece = piece.ljust(collen) unless eol
- print piece
- puts if eol
- }
- # no need to finish it up, because eol is always true for the last element
- end
-end
-
-# get nr of chars that fit in window or console, see PLEAC 15.4
-# not portable -- linux only (?)
-def getWinCharWidth()
- buf = "\0" * 8
- $stdout.ioctl(0x5413, buf)
- ws_row, ws_col, ws_xpixel, ws_ypixel = buf.unpack("$4")
- ws_col || 80
-rescue
- 80
-end
-
-# main program
-cols = getWinCharWidth()
-formatter = WordFormatter.new(cols)
-words = readlines()
-words.collect! { |line|
- line.chomp
-}
-formatter.output(words)
-
-
-# @@PLEAC@@_4.19
-# In ruby, Fixnum's are automatically converted to Bignum's when
-# needed, so there is no need for an extra module
-def factorial(n)
- s = 1
- while n > 0
- s *= n
- n -= 1
- end
- s
-end
-
-puts factorial(500)
-
-#---------------------------------------------------------
-# Example 4-3. tsc-permute
-# tsc_permute: permute each word of input
-def permute(items, perms)
- unless items.length > 0
- puts perms.join(" ")
- else
- for i in items
- newitems = items.dup
- newperms = perms.dup
- newperms.unshift(newitems.delete(i))
- permute(newitems, newperms)
- end
- end
-end
-# In ruby the main program must be after all definitions it is using
-permute(ARGV, [])
-
-#---------------------------------------------------------
-# mjd_permute: permute each word of input
-
-def factorial(n)
- s = 1
- while n > 0
- s *= n
- n -= 1
- end
- s
-end
-
-# we use a class with a class variable store the private cache
-# for the results of the factorial function.
-class Factorial
- @@fact = [ 1 ]
- def Factorial.compute(n)
- if @@fact[n]
- @@fact[n]
- else
- @@fact[n] = n * Factorial.compute(n - 1)
- end
- end
-end
-
-#---------------------------------------------------------
-# Example 4-4- mjd-permute
-# n2pat(n, len): produce the N-th pattern of length len
-
-# We must use a lower case letter as parameter N, otherwise it is
-# handled as constant Length is the length of the resulting
-# array, not the index of the last element (length -1) like in
-# the perl example.
-def n2pat(n, length)
- pat = []
- i = 1
- while i <= length
- pat.push(n % i)
- n /= i
- i += 1
- end
- pat
-end
-
-# pat2perm(pat): turn pattern returned by n2pat() into
-# permutation of integers.
-def pat2perm(pat)
- source = (0 .. pat.length - 1).to_a
- perm = []
- perm.push(source.slice!(pat.pop)) while pat.length > 0
- perm
-end
-
-def n2perm(n, len)
- pat2perm(n2pat(n,len))
-end
-
-# In ruby the main program must be after all definitions
-while gets
- data = split
- # the perl solution has used $#data, which is length-1
- num_permutations = Factorial.compute(data.length())
- 0.upto(num_permutations - 1) do |i|
- # in ruby we can not use an array as selector for an array
- # but by exchanging the two arrays, we can use the collect method
- # which returns an array with the result of all block invocations
- permutation = n2perm(i, data.length).collect {
- |j| data[j]
- }
- puts permutation.join(" ")
- end
-end
-
-
-# @@PLEAC@@_5.0
-age = { "Nat", 24,
- "Jules", 25,
- "Josh", 17 }
-
-age["Nat"] = 24
-age["Jules"] = 25
-age["Josh"] = 17
-
-food_color = {
- "Apple" => "red",
- "Banana" => "yellow",
- "Lemon" => "yellow",
- "Carrot" => "orange"
- }
-
-# In Ruby, you cannot avoid the double or simple quoting
-# while manipulatin hashes
-
-
-# @@PLEAC@@_5.1
-hash[key] = value
-
-food_color["Raspberry"] = "pink"
-puts "Known foods:", food_color.keys
-
-
-# @@PLEAC@@_5.2
-# does hash have a value for key ?
-if (hash.has_key?(key))
- # it exists
-else
- # it doesn't
-end
-
-[ "Banana", "Martini" ].each { |name|
- print name, " is a ", food_color.has_key?(name) ? "food" : "drink", "\n"
-}
-
-age = {}
-age['Toddler'] = 3
-age['Unborn'] = 0
-age['Phantasm'] = nil
-
-for thing in ['Toddler', 'Unborn', 'Phantasm', 'Relic']
- print "#{thing}: "
- print "Has-key " if age.has_key?(thing)
- print "True " if age[thing]
- print "Nonzero " if age[thing] && age[thing].nonzero?
- print "\n"
-end
-
-#=>
-# Toddler: Has-key True Nonzero
-# Unborn: Has-key True
-# Phantasm: Has-key
-# Relic:
-
-# You use Hash#has_key? when you use Perl's exists -> it checks
-# for existence of a key in a hash.
-# All Numeric are "True" in ruby, so the test doesn't have the
-# same semantics as in Perl; you would use Numeric#nonzero? to
-# achieve the same semantics (false if 0, true otherwise).
-
-
-# @@PLEAC@@_5.3
-food_color.delete("Banana")
-
-
-# @@PLEAC@@_5.4
-hash.each { |key, value|
- # do something with key and value
-}
-
-hash.each_key { |key|
- # do something with key
-}
-
-food_color.each { |food, color|
- puts "#{food} is #{color}"
-}
-
-food_color.each_key { |food|
- puts "#{food} is #{food_color[food]}"
-}
-
-# IMO this demonstrates that OO style is by far more readable
-food_color.keys.sort.each { |food|
- puts "#{food} is #{food_color[food]}."
-}
-
-#-----------------------------
-#!/usr/bin/ruby
-# countfrom - count number of messages from each sender
-
-# Default value is 0
-from = Hash.new(0)
-while gets
- /^From: (.*)/ and from[$1] += 1
-end
-
-# More useful to sort by number of received mail by person
-from.sort {|a,b| b[1]<=>a[1]}.each { |v|
- puts "#{v[1]}: #{v[0]}"
-}
-#-----------------------------
-
-
-# @@PLEAC@@_5.5
-# You may use the built-in 'inspect' method this way:
-p hash
-
-# Or do it the Cookbook way:
-hash.each { |k,v| puts "#{k} => #{v}" }
-
-# Sorted by keys
-hash.sort.each { |e| puts "#{e[0]} => #{e[1]}" }
-# Sorted by values
-hash.sort{|a,b| a[1]<=>b[1]}.each { |e| puts "#{e[0]} => #{e[1]}" }
-
-
-# @@PLEAC@@_5.7
-ttys = Hash.new
-for i in `who`
- user, tty = i.split
- (ttys[user] ||= []) << tty # see problems_ruby for more infos
-end
-ttys.keys.sort.each { |k|
- puts "#{k}: #{commify_series(ttys[k])}" # from 4.2
-}
-
-
-# @@PLEAC@@_5.8
-surname = { "Mickey" => "Mantle", "Babe" => "Ruth" }
-puts surname.index("Mantle")
-
-# If you really needed to 'invert' the whole hash, use Hash#invert
-
-#-----------------------------
-#!/usr/bin/ruby -w
-# foodfind - find match for food or color
-
-given = ARGV.shift or raise "usage: foodfind food_or_color"
-
-color = {
- "Apple" => "red",
- "Banana" => "yellow",
- "Lemon" => "yellow",
- "Carrot" => "orange",
-}
-
-if (color.has_key?(given))
- puts "#{given} is a food with color #{color[given]}."
-end
-if (color.has_value?(given))
- puts "#{color.index(given)} is a food with color #{given}."
-end
-#-----------------------------
-
-
-# @@PLEAC@@_5.9
-# Sorted by keys (Hash#sort gives an Array of pairs made of each key,value)
-food_color.sort.each { |f|
- puts "#{f[0]} is #{f[1]}."
-}
-
-# Sorted by values
-food_color.sort { |a,b| a[1] <=> b[1] }.each { |f|
- puts "#{f[0]} is #{f[1]}."
-}
-
-# Sorted by length of values
-food_color.sort { |a,b| a[1].length <=> b[1].length }.each { |f|
- puts "#{f[0]} is #{f[1]}."
-}
-
-
-# @@PLEAC@@_5.10
-merged = a.clone.update(b) # because Hash#update changes object in place
-
-drink_color = { "Galliano" => "yellow", "Mai Tai" => "blue" }
-ingested_color = drink_color.clone.update(food_color)
-
-substance_color = {}
-for i in [ food_color, drink_color ]
- i.each_key { |k|
- if substance_color.has_key?(k)
- puts "Warning: #{k} seen twice. Using the first definition."
- next
- end
- substance_color[k] = 1
- }
-end
-
-
-# @@PLEAC@@_5.11
-common = hash1.keys & hash2.keys
-
-this_not_that = hash1.keys - hash2.keys
-
-
-# @@PLEAC@@_5.12
-# no problem here, Ruby handles any kind of object for key-ing
-# (it takes Object#hash, which defaults to Object#id)
-
-
-# @@PLEAC@@_5.13
-# AFAIK, not possible in Ruby
-
-
-# @@PLEAC@@_5.14
-# Be careful, the following is possible only because Fixnum objects are
-# special (documentation says: there is effectively only one Fixnum object
-# instance for any given integer value).
-count = Hash.new(0)
-array.each { |e|
- count[e] += 1
-}
-
-
-# @@PLEAC@@_5.15
-father = {
- "Cain" , "Adam",
- "Abel" , "Adam",
- "Seth" , "Adam",
- "Enoch" , "Cain",
- "Irad" , "Enoch",
- "Mehujael" , "Irad",
- "Methusael" , "Mehujael",
- "Lamech" , "Methusael",
- "Jabal" , "Lamech",
- "Jubal" , "Lamech",
- "Tubalcain" , "Lamech",
- "Enos" , "Seth",
-}
-
-while gets
- chomp
- begin
- print $_, " "
- end while $_ = father[$_]
- puts
-end
-
-children = {}
-father.each { |k,v|
- (children[v] ||= []) << k
-}
-while gets
- chomp
- puts "#{$_} begat #{(children[$_] || ['Nobody']).join(', ')}.\n"
-end
-
-includes = {}
-files.each { |f|
- begin
- for l in IO.readlines(f)
- next unless l =~ /^\s*#\s*include\s*<([^>]+)>/
- (includes[$1] ||= []) << f
- end
- rescue SystemCallError
- $stderr.puts "#$! (skipping)"
- end
-}
-
-include_free = includes.values.flatten.uniq - includes.keys
-
-
-# @@PLEAC@@_5.16
-# dutree - print sorted intented rendition of du output
-#% dutree
-#% dutree /usr
-#% dutree -a
-#% dutree -a /bin
-
-# The DuNode class collects all information about a directory,
-# and provides some convenience methods
-class DuNode
-
- attr_reader :name
- attr_accessor :size
- attr_accessor :kids
-
- def initialize(name)
- @name = name
- @kids = []
- @size = 0
- end
-
- # support for sorting nodes with side
- def size_compare(node2)
- @size <=> node2.size
- end
-
- def basename
- @name.sub(/.*\//, "")
- end
-
- #returns substring before last "/", nil if not there
- def parent
- p = @name.sub(/\/[^\/]+$/,"")
- if p == @name
- nil
- else
- p
- end
- end
-
-end
-
-# The DuTree does the acdtual work of
-# getting the input, parsing it, builging up a tree
-# and format it for output
-class Dutree
-
- attr_reader :topdir
-
- def initialize
- @nodes = Hash.new
- @dirsizes = Hash.new(0)
- @kids = Hash.new([])
- end
-
- # get a node by name, create it if it does not exist yet
- def get_create_node(name)
- if @nodes.has_key?(name)
- @nodes[name]
- else
- node = DuNode.new(name)
- @nodes[name] = node
- node
- end
- end
-
- # run du, read in input, save sizes and kids
- # stores last directory read in instance variable topdir
- def input(arguments)
- name = ""
- cmd = "du " + arguments.join(" ")
- IO.popen(cmd) { |pipe|
- pipe.each { |line|
- size, name = line.chomp.split(/\s+/, 2)
- node = get_create_node(name)
- node.size = size.to_i
- @nodes[name] = node
- parent = node.parent
- if parent
- get_create_node(parent).kids.push(node)
- end
- }
- }
- @topdir = @nodes[name]
- end
-
- # figure out how much is taken in each directory
- # that isn't stored in the subdirectories. Add a new
- # fake kid called "." containing that much.
- def get_dots(node)
- cursize = node.size
- for kid in node.kids
- cursize -= kid.size
- get_dots(kid)
- end
- if node.size != cursize
- newnode = get_create_node(node.name + "/.")
- newnode.size = cursize
- node.kids.push(newnode)
- end
- end
-
- # recursively output everything
- # passing padding and number width as well
- # on recursive calls
- def output(node, prefix="", width=0)
- line = sprintf("%#{width}d %s", node.size, node.basename)
- puts(prefix + line)
- prefix += line.sub(/\d /, "| ")
- prefix.gsub!(/[^|]/, " ")
- if node.kids.length > 0 # not a bachelor node
- kids = node.kids
- kids.sort! { |a,b|
- b.size_compare(a)
- }
- width = kids[0].size.to_s.length
- for kid in kids
- output(kid, prefix, width)
- end
- end
- end
-
-end
-
-tree = Dutree.new
-tree.input(ARGV)
-tree.get_dots(tree.topdir)
-tree.output(tree.topdir)
-
-
-# @@PLEAC@@_6.0
-# The verbose version are match, sub, gsub, sub! and gsub!;
-# pattern needs to be a Regexp object; it yields a MatchData
-# object.
-pattern.match(string)
-string.sub(pattern, replacement)
-string.gsub(pattern, replacement)
-# As usual in Ruby, sub! does the same as sub but also modifies
-# the object, the same for gsub!/gsub.
-
-# Sugared syntax yields the position of the match (or nil if no
-# match). Note that the object at the right of the operator needs
-# not to be a Regexp object (it can be a String). The "dont
-# match" operator yields true or false.
-meadow =~ /sheep/ # position of the match, nil if no match
-meadow !~ /sheep/ # true if doesn't match, false if it does
-# There is no sugared version for the substitution
-
-meadow =~ /\bovines?\b/i and print "Here be sheep!"
-
-string = "good food"
-string.sub!(/o*/, 'e')
-
-# % echo ababacaca | ruby -ne 'puts $& if /(a|ba|b)+(a|ac)+/'
-# ababa
-
-# The "global" (or "multiple") match is handled by String#scan
-scan (/(\d+)/) {
- puts "Found number #{$1}"
-}
-
-# String#scan yields an Array if not used with a block
-numbers = scan(/\d+/)
-
-digits = "123456789"
-nonlap = digits.scan(/(\d\d\d)/)
-yeslap = digits.scan(/(?=(\d\d\d))/)
-puts "Non-overlapping: #{nonlap.join(' ')}"
-puts "Overlapping: #{yeslap.join(' ')}";
-# Non-overlapping: 123 456 789
-# Overlapping: 123 234 345 456 567 678 789
-
-string = "And little lambs eat ivy"
-string =~ /l[^s]*s/
-puts "(#$`) (#$&) (#$')"
-# (And ) (little lambs) ( eat ivy)
-
-
-# @@PLEAC@@_6.1
-# Ruby doesn't have the same problem:
-dst = src.sub('this', 'that')
-
-progname = $0.sub('^.*/', '')
-
-bindirs = %w(/usr/bin /bin /usr/local/bin)
-libdirs = bindirs.map { |l| l.sub('bin', 'lib') }
-
-
-# @@PLEAC@@_6.3
-/\S+/ # as many non-whitespace bytes as possible
-/[A-Za-z'-]+/ # as many letters, apostrophes, and hyphens
-
-/\b([A-Za-z]+)\b/ # usually best
-/\s([A-Za-z]+)\s/ # fails at ends or w/ punctuation
-
-
-# @@PLEAC@@_6.4
-require 'socket'
-str = 'www.ruby-lang.org and www.rubygarden.org'
-re = /
- ( # capture the hostname in $1
- (?: # these parens for grouping only
- (?! [-_] ) # lookahead for neither underscore nor dash
- [\w-] + # hostname component
- \. # and the domain dot
- ) + # now repeat that whole thing a bunch of times
- [A-Za-z] # next must be a letter
- [\w-] + # now trailing domain part
- ) # end of $1 capture
- /x # /x for nice formatting
-
-str.gsub! re do # pass a block to execute replacement
- host = TCPsocket.gethostbyname($1)
- "#{$1} [#{host[3]}]"
-end
-
-puts str
-#-----------------------------
-# to match whitespace or #-characters in an extended re you need to escape
-# them.
-
-foo = 42
-str = 'blah #foo# blah'
-str.gsub! %r/ # replace
- \# # a pound sign
- (\w+) # the variable name
- \# # another pound sign
- /x do
- eval $1 # with the value of a local variable
- end
-puts str # => blah 42 blah
-
-
-# @@PLEAC@@_6.5
-# The 'g' modifier doesn't exist in Ruby, a regexp can't be used
-# directly in a while loop; instead, use String#scan { |match| .. }
-fish = 'One fish two fish red fish blue fish'
-WANT = 3
-count = 0
-fish.scan(/(\w+)\s+fish\b/i) {
- if (count += 1) == WANT
- puts "The third fish is a #{$1} one."
- end
-}
-
-if fish =~ /(?:\w+\s+fish\s+){2}(\w+)\s+fish/i
- puts "The third fish is a #{$1} one."
-end
-
-pond = 'One fish two fish red fish blue fish'
-# String#scan without a block gives an array of matches, each match
-# being an array of all the specified groups
-colors = pond.scan(/(\w+)\s+fish\b/i).flatten # get all matches
-color = colors[2] # then the one we want
-# or without a temporary array
-color = pond.scan(/(\w+)\s+fish\b/i).flatten[2] # just grab element 3
-puts "The third fish in the pond is #{color}."
-
-count = 0
-fishes = 'One fish two fish red fish blue fish'
-evens = fishes.scan(/(\w+)\s+fish\b/i).select { (count+=1) % 2 == 0 }
-print "Even numbered fish are #{evens.join(' ')}."
-
-count = 0
-fishes.gsub(/
- \b # makes next \w more efficient
- ( \w+ ) # this is what we\'ll be changing
- (
- \s+ fish \b
- )
- /x) {
- if (count += 1) == 4
- 'sushi' + $2
- else
- $1 + $2
- end
-}
-
-pond = 'One fish two fish red fish blue fish swim here.'
-puts "Last fish is #{pond.scan(/\b(\w+)\s+fish\b/i).flatten[-1]}"
-
-/
- A # find some pattern A
- (?! # mustn\'t be able to find
- .* # something
- A # and A
- )
- $ # through the end of the string
-/x
-
-# The "s" perl modifier is "m" in Ruby (not very nice since there is
-# also an "m" in perl..)
-pond = "One fish two fish red fish blue fish swim here."
-if (pond =~ /
- \b ( \w+) \s+ fish \b
- (?! .* \b fish \b )
- /mix)
- puts "Last fish is #{$1}."
-else
- puts "Failed!"
-end
-
-
-# @@PLEAC@@_6.6
-#-----------------------------
-#!/usr/bin/ruby -w
-# killtags - very bad html killer
-$/ = nil; # each read is whole file
-while file = gets() do
- file.gsub!(/<.*?>/m,''); # strip tags (terribly)
- puts file # print file to STDOUT
-end
-#-----------------------------
-#!/usr/bin/ruby -w
-#headerfy - change certain chapter headers to html
-$/ = ''
-while file = gets() do
- pattern = /
- \A # start of record
- ( # capture in $1
- Chapter # text string
- \s+ # mandatory whitespace
- \d+ # decimal number
- \s* # optional whitespace
- : # a real colon
- . * # anything not a newline till end of line
- )
- /x
- puts file.gsub(pattern,'<H1>\1</H1>')
-end
-#-----------------------------
-#% ruby -00pe "gsub!(/\A(Chapter\s+\d+\s*:.*)/,'<H1>\1</H1>')" datafile
-
-#!/usr/bin/ruby -w
-#-----------------------------
-for file in ARGV
- file = File.open(ARGV.shift)
- while file.gets('') do # each read is a paragraph
- print "chunk #{$.} in $ARGV has <<#{$1}>>\n" while /^START(.*?)^END/m
- end # /m activates the multiline mode
-end
-#-----------------------------
-
-# @@PLEAC@@_6.7
-#-----------------------------
-$/ = nil;
-file = File.open("datafile")
-chunks = file.gets.split(/pattern/)
-#-----------------------------
-# .Ch, .Se and .Ss divide chunks of STDIN
-chunks = gets(nil).split(/^\.(Ch|Se|Ss)$/)
-print "I read #{chunks.size} chunks.\n"
-#-----------------------------
-
-
-# @@PLEAC@@_6.8
-while gets
- if ~/BEGIN/ .. ~/END/
- # line falls between BEGIN and END inclusive
- end
-end
-
-while gets
- if ($. == firstnum) .. ($. == lastnum)
- # operate between firstnum and lastnum line number
- end
-end
-
-# in ruby versions prior to 1.8, the above two conditional
-# expressions could be shortened to:
-# if /BEGIN/ .. /END/
-# and
-# if firstnum .. lastnum
-# but these now only work this way from the command line
-
-#-----------------------------
-
-while gets
- if ~/BEGIN/ ... ~/END/
- # line falls between BEGIN and END on different lines
- end
-end
-
-while gets
- if ($. == first) ... ($. == last)
- # operate between first and last line number on different lines
- end
-end
-
-#-----------------------------
-# command-line to print lines 15 through 17 inclusive (see below)
-ruby -ne 'print if 15 .. 17' datafile
-
-# print out all <XMP> .. </XMP> displays from HTML doc
-while gets
- print if ~%r#<XMP>#i .. ~%r#</XMP>#i;
-end
-
-# same, but as shell command
-# ruby -ne 'print if %r#<XMP>#i .. %r#</XMP>#i' document.html
-#-----------------------------
-# ruby -ne 'BEGIN { $top=3; $bottom=5 }; \
-# print if $top .. $bottom' /etc/passwd # FAILS
-# ruby -ne 'BEGIN { $top=3; $bottom=5 }; \
-# print if $. == $top .. $. == $bottom' /etc/passwd # works
-# ruby -ne 'print if 3 .. 5' /etc/passwd # also works
-#-----------------------------
-print if ~/begin/ .. ~/end/;
-print if ~/begin/ ... ~/end/;
-#-----------------------------
-while gets
- $in_header = $. == 1 .. ~/^$/ ? true : false
- $in_body = ~/^$/ .. ARGF.eof ? true : false
-end
-#-----------------------------
-seen = {}
-ARGF.each do |line|
- next unless line =~ /^From:?\s/i .. line =~ /^$/;
- line.scan(%r/([^<>(),;\s]+\@[^<>(),;\s]+)/).each do |addr|
- puts addr unless seen[addr]
- seen[addr] ||= 1
- end
-end
-
-
-# @@PLEAC@@_6.9
-def glob2pat(globstr)
- patmap = {
- '*' => '.*',
- '?' => '.',
- '[' => '[',
- ']' => ']',
- }
- globstr.gsub!(/(.)/) { |c| patmap[c] || Regexp::escape(c) }
- '^' + globstr + '$'
-end
-
-
-# @@PLEAC@@_6.10
-# avoid interpolating patterns like this if the pattern
-# isn't going to change:
-pattern = ARGV.shift
-ARGF.each do |line|
- print line if line =~ /#{pattern}/
-end
-
-# the above creates a new regex each iteration. Instead,
-# use the /o modifier so the regex is compiled only once
-
-pattern = ARGV.shift
-ARGF.each do |line|
- print line if line =~ /#{pattern}/o
-end
-
-#-----------------------------
-
-#!/usr/bin/ruby
-# popgrep1 - grep for abbreviations of places that say "pop"
-# version 1: slow but obvious way
-popstates = %w(CO ON MI WI MN)
-ARGF.each do |line|
- popstates.each do |state|
- if line =~ /\b#{state}\b/
- print line
- last
- end
- end
-end
-
-#-----------------------------
-#!/usr/bin/ruby
-# popgrep2 - grep for abbreviations of places that say "pop"
-# version 2: eval strings; fast but hard to quote
-popstates = %w(CO ON MI WI MN)
-code = "ARGF.each do |line|\n"
-popstates.each do |state|
- code += "\tif line =~ /\\b#{state}\\b/; print(line); next; end\n"
-end
-code += "end\n"
-print "CODE IS\n---\n#{code}\n---\n" if false # turn on for debugging
-eval code
-
-# CODE IS
-# ---
-# ARGF.each do |line|
-# if line =~ /\bCO\b/; print(line); next; end
-# if line =~ /\bON\b/; print(line); next; end
-# if line =~ /\bMI\b/; print(line); next; end
-# if line =~ /\bWI\b/; print(line); next; end
-# if line =~ /\bMN\b/; print(line); next; end
-# end
-#
-# ---
-
-## alternatively, the same idea as above but compiling
-## to a case statement: (not in perlcookbook)
-#!/usr/bin/ruby -w
-# popgrep2.5 - grep for abbreviations of places that say "pop"
-# version 2.5: eval strings; fast but hard to quote
-popstates = %w(CO ON MI WI MN)
-code = "ARGF.each do |line|\n case line\n"
-popstates.each do |state|
- code += " when /\\b#{state}\\b/ : print line\n"
-end
-code += " end\nend\n"
-print "CODE IS\n---\n#{code}\n---\n" if false # turn on for debugging
-eval code
-
-# CODE IS
-# ---
-# ARGF.each do |line|
-# case line
-# when /\bCO\b/ : print line
-# when /\bON\b/ : print line
-# when /\bMI\b/ : print line
-# when /\bWI\b/ : print line
-# when /\bMN\b/ : print line
-# end
-# end
-#
-# ---
-
-# Note: (above) Ruby 1.8+ allows the 'when EXP : EXPR' on one line
-# with the colon separator.
-
-#-----------------------------
-#!/usr/bin/ruby
-# popgrep3 - grep for abbreviations of places that say "pop"
-# version3: build a match_any function
-popstates = %w(CO ON MI WI MN)
-expr = popstates.map{|e|"line =~ /\\b#{e}\\b/"}.join('||')
-eval "def match_any(line); #{expr};end"
-ARGF.each do |line|
- print line if match_any(line)
-end
-#-----------------------------
-
-## building a match_all function is a trivial
-## substitution of && for ||
-## here is a generalized example:
-#!/usr/bin/ruby -w
-## grepauth - print lines that mention both foo and bar
-class MultiMatch
- def initialize(*patterns)
- _any = build_match('||',patterns)
- _all = build_match('&&',patterns)
- eval "def match_any(line);#{_any};end\n"
- eval "def match_all(line);#{_all};end\n"
- end
- def build_match(sym,args)
- args.map{|e|"line =~ /#{e}/"}.join(sym)
- end
-end
-
-mm = MultiMatch.new('foo','bar')
-ARGF.each do |line|
- print line if mm.match_all(line)
-end
-#-----------------------------
-
-#!/usr/bin/ruby
-# popgrep4 - grep for abbreviations of places that say "pop"
-# version4: pretty fast, but simple: compile all re's first:
-popstates = %w(CO ON MI WI MN)
-popstates = popstates.map{|re| %r/\b#{re}\b/}
-ARGF.each do |line|
- popstates.each do |state_re|
- if line =~ state_re
- print line
- break
- end
- end
-end
-
-## speeds trials on the jargon file(412): 26006 lines, 1.3MB
-## popgrep1 => 7.040s
-## popgrep2 => 0.656s
-## popgrep2.5 => 0.633s
-## popgrep3 => 0.675s
-## popgrep4 => 1.027s
-
-# unless speed is criticial, the technique in popgrep4 is a
-# reasonable balance between speed and logical simplicity.
-
-
-# @@PLEAC@@_6.11
-begin
- print "Pattern? "
- pat = $stdin.gets.chomp
- Regexp.new(pat)
-rescue
- warn "Invalid Pattern"
- retry
-end
-
-
-# @@PLEAC@@_6.13
-# uses the 'amatch' extension found on:
-# http://raa.ruby-lang.org/project/amatch/
-require 'amatch'
-matcher = Amatch.new('balast')
-#$relative, $distance = 0, 1
-File.open('/usr/share/dict/words').each_line do |line|
- print line if matcher.search(line) <= 1
-end
-__END__
-#CODE
-ballast
-ballasts
-balustrade
-balustrades
-blast
-blasted
-blaster
-blasters
-blasting
-blasts
-
-
-# @@PLEAC@@_6.14
-str.scan(/\G(\d)/).each do |token|
- puts "found #{token}"
-end
-#-----------------------------
-n = " 49 here"
-n.gsub!(/\G /,'0')
-puts n
-#-----------------------------
-str = "3,4,5,9,120"
-str.scan(/\G,?(\d+)/).each do |num|
- puts "Found number: #{num}"
-end
-#-----------------------------
-# Ruby doesn't have the String.pos or a /c re modifier like Perl
-# But it does have StringScanner in the standard library (strscn)
-# which allows similar functionality:
-
-require 'strscan'
-text = 'the year 1752 lost 10 days on the 3rd of September'
-sc = StringScanner.new(text)
-while sc.scan(/.*?(\d+)/)
- print "found: #{sc[1]}\n"
-end
-if sc.scan(/\S+/)
- puts "Found #{sc[0]} after last number"
-end
-#-----------------------------
-# assuming continuing from above:
-puts "The position in 'text' is: #{sc.pos}"
-sc.pos = 30
-puts "The position in 'text' is: #{sc.pos}"
-
-
-# @@PLEAC@@_6.15
-#-----------------------------
-# greedy pattern
-str.gsub!(/<.*>/m,'') # not good
-
-# non-greedy (minimal) pattern
-str.gsub!(/<.*?>/m,'') # not great
-
-
-#-----------------------------
-#<b><i>this</i> and <i>that</i> are important</b> Oh, <b><i>me too!</i></b>
-#-----------------------------
-%r{ <b><i>(.*?)</i></b> }mx
-#-----------------------------
-%r/BEGIN((?:(?!BEGIN).)*)END/
-#-----------------------------
-%r{ <b><i>( (?: (?!</b>|</i>). )* ) </i></b> }mx
-#-----------------------------
-%r{ <b><i>( (?: (?!</[ib]>). )* ) </i></b> }mx
-#-----------------------------
-%r{
- <b><i>
- [^<]* # stuff not possibly bad, and not possibly the end.
- (?:
- # at this point, we can have '<' if not part of something bad
- (?! </?[ib]> ) # what we can't have
- < # okay, so match the '<'
- [^<]* # and continue with more safe stuff
- ) *
- </i></b>
- }mx
-
-
-# @@PLEAC@@_6.16
-#-----------------------------
-$/ = ""
-ARGF.each do |para|
- para.scan %r/
- \b # start at word boundary
- (\S+) # find chunk of non-whitespace
- \b # until a word boundary
- (
- \s+ # followed by whitespace
- \1 # and that same chunk again
- \b # and a word boundary
- ) + # one or more times
- /xi do
- puts "dup word '#{$1}' at paragraph #{$.}"
- end
-end
-#-----------------------------
-astr = 'nobody'
-bstr = 'bodysnatcher'
-if "#{astr} #{bstr}" =~ /^(\w+)(\w+) \2(\w+)$/
- print "#{$2} overlaps in #{$1}-#{$2}-#{$3}"
-end
-#-----------------------------
-#!/usr/bin/ruby -w
-# prime_pattern -- find prime factors of argument using patterns
-ARGV << 180
-cap = 'o' * ARGV.shift
-while cap =~ /^(oo+?)\1+$/
- print $1.size, " "
- cap.gsub!(/#{$1}/,'o')
-end
-puts cap.size
-#-----------------------------
-#diophantine
-# solve for 12x + 15y + 16z = 281, maximizing x
-if ('o' * 281).match(/^(o*)\1{11}(o*)\2{14}(o*)\3{15}$/)
- x, y, z = $1.size, $2.size, $3.size
- puts "One solution is: x=#{x}; y=#{y}; z=#{z}"
-else
- puts "No solution."
-end
-# => One solution is: x=17; y=3; z=2
-
-#-----------------------------
-# using different quantifiers:
-('o' * 281).match(/^(o+)\1{11}(o+)\2{14}(o+)\3{15}$/)
-# => One solution is: x=17; y=3; z=2
-
-('o' * 281).match(/^(o*?)\1{11}(o*)\2{14}(o*)\3{15}$/)
-# => One solution is: x=0; y=7; z=11
-
-('o' * 281).match(/^(o+?)\1{11}(o*)\2{14}(o*)\3{15}$/)
-# => One solution is: x=1; y=3; z=14
-
-
-# @@PLEAC@@_6.17
-# alpha OR beta
-%r/alpha|beta/
-
-# alpha AND beta
-%r/(?=.*alpha)(?=.*beta)/m
-
-# alpha AND beta, no overlap
-%r/alpha.*beta|beta.*alpha/m
-
-# NOT beta
-%r/^(?:(?!beta).)*$/m
-
-# NOT bad BUT good
-%r/(?=(?:(?!BAD).)*$)GOOD/m
-#-----------------------------
-
-if !(string =~ /pattern/) # ugly
- something()
-end
-
-if string !~ /pattern/ # preferred
- something()
-end
-
-
-#-----------------------------
-if string =~ /pat1/ && string =~ /pat2/
- something()
-end
-#-----------------------------
-if string =~ /pat1/ || string =~ /pat2/
- something()
-end
-#-----------------------------
-#!/usr/bin/ruby -w
-# minigrep - trivial grep
-pat = ARGV.shift
-ARGF.each do |line|
- print line if line =~ /#{pat}/o
-end
-#-----------------------------
- "labelled" =~ /^(?=.*bell)(?=.*lab)/m
-#-----------------------------
-$string =~ /bell/ && $string =~ /lab/
-#-----------------------------
-$murray_hill = "blah bell blah "
-if $murray_hill =~ %r{
- ^ # start of string
- (?= # zero-width lookahead
- .* # any amount of intervening stuff
- bell # the desired bell string
- ) # rewind, since we were only looking
- (?= # and do the same thing
- .* # any amount of intervening stuff
- lab # and the lab part
- )
- }mx # /m means . can match newline
-
- print "Looks like Bell Labs might be in Murray Hill!\n";
-end
-#-----------------------------
-"labelled" =~ /(?:^.*bell.*lab)|(?:^.*lab.*bell)/
-#-----------------------------
-$brand = "labelled";
-if $brand =~ %r{
- (?: # non-capturing grouper
- ^ .*? # any amount of stuff at the front
- bell # look for a bell
- .*? # followed by any amount of anything
- lab # look for a lab
- ) # end grouper
- | # otherwise, try the other direction
- (?: # non-capturing grouper
- ^ .*? # any amount of stuff at the front
- lab # look for a lab
- .*? # followed by any amount of anything
- bell # followed by a bell
- ) # end grouper
- }mx # /m means . can match newline
- print "Our brand has bell and lab separate.\n";
-end
-#-----------------------------
-$map =~ /^(?:(?!waldo).)*$/s
-#-----------------------------
-$map = "the great baldo"
-if $map =~ %r{
- ^ # start of string
- (?: # non-capturing grouper
- (?! # look ahead negation
- waldo # is he ahead of us now?
- ) # is so, the negation failed
- . # any character (cuzza /s)
- ) * # repeat that grouping 0 or more
- $ # through the end of the string
- }mx # /m means . can match newline
- print "There's no waldo here!\n";
-end
-=begin
- 7:15am up 206 days, 13:30, 4 users, load average: 1.04, 1.07, 1.04
-
-USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
-
-tchrist tty1 5:16pm 36days 24:43 0.03s xinit
-
-tchrist tty2 5:19pm 6days 0.43s 0.43s -tcsh
-
-tchrist ttyp0 chthon 7:58am 3days 23.44s 0.44s -tcsh
-
-gnat ttyS4 coprolith 2:01pm 13:36m 0.30s 0.30s -tcsh
-=end
-#% w | minigrep '^(?!.*ttyp).*tchrist'
-#-----------------------------
-%r{
- ^ # anchored to the start
- (?! # zero-width look-ahead assertion
- .* # any amount of anything (faster than .*?)
- ttyp # the string you don't want to find
- ) # end look-ahead negation; rewind to start
- .* # any amount of anything (faster than .*?)
- tchrist # now try to find Tom
-}x
-#-----------------------------
-#% w | grep tchrist | grep -v ttyp
-#-----------------------------
-#% grep -i 'pattern' files
-#% minigrep '(?i)pattern' files
-#-----------------------------
-
-
-# @@PLEAC@@_6.20
-ans = $stdin.gets.chomp
-re = %r/^#{Regexp.quote(ans)}/
-case
- when "SEND" =~ re : puts "Action is send"
- when "STOP" =~ re : puts "Action is stop"
- when "ABORT" =~ re : puts "Action is abort"
- when "EDIT" =~ re : puts "Action is edit"
-end
-#-----------------------------
-require 'abbrev'
-table = Abbrev.abbrev %w-send stop abort edit-
-loop do
- print "Action: "
- ans = $stdin.gets.chomp
- puts "Action for #{ans} is #{table[ans.downcase]}"
-end
-
-
-#-----------------------------
-# dummy values are defined for 'file', 'PAGER', and
-# the 'invoke_editor' and 'deliver_message' methods
-# do not do anything interesting in this example.
-#!/usr/bin/ruby -w
-require 'abbrev'
-
-file = 'pleac_ruby.data'
-PAGER = 'less'
-
-def invoke_editor
- puts "invoking editor"
-end
-
-def deliver_message
- puts "delivering message"
-end
-
-actions = {
- 'edit' => self.method(:invoke_editor),
- 'send' => self.method(:deliver_message),
- 'list' => proc {system(PAGER, file)},
- 'abort' => proc {puts "See ya!"; exit},
- "" => proc {puts "Unknown Command"}
-}
-
-dtable = Abbrev.abbrev(actions.keys)
-loop do
- print "Action: "
- ans = $stdin.gets.chomp.delete(" \t")
- actions[ dtable[ans.downcase] || "" ].call
-end
-
-
-# @@PLEAC@@_6.19
-#-----------------------------
-# basically, the Perl Cookbook categorizes this as an
-# unsolvable problem ...
-#-----------------------------
-1 while addr.gsub!(/\([^()]*\)/,'')
-#-----------------------------
-Dear someuser@host.com,
-
-Please confirm the mail address you gave us Wed May 6 09:38:41
-MDT 1998 by replying to this message. Include the string
-"Rumpelstiltskin" in that reply, but spelled in reverse; that is,
-start with "Nik...". Once this is done, your confirmed address will
-be entered into our records.
-
-
-# @@PLEAC@@_6.21
-#-----------------------------
-#% gunzip -c ~/mail/archive.gz | urlify > archive.urlified
-#-----------------------------
-#% urlify ~/mail/*.inbox > ~/allmail.urlified
-#-----------------------------
-#!/usr/bin/ruby -w
-# urlify - wrap HTML links around URL-like constructs
-
-urls = '(https?|telnet|gopher|file|wais|ftp)';
-ltrs = '\w';
-gunk = '/#~:.?+=&%@!\-';
-punc = '.:?\-';
-any = "#{ltrs}#{gunk}#{punc}";
-
-ARGF.each do |line|
- line.gsub! %r/
- \b # start at word boundary
- ( # begin $1 {
- #{urls} : # need resource and a colon
- [#{any}] +? # followed by on or more
- # of any valid character, but
- # be conservative and take only
- # what you need to....
- ) # end $1 }
- (?= # look-ahead non-consumptive assertion
- [#{punc}]* # either 0 or more punctuation
- [^#{any}] # followed by a non-url char
- | # or else
- $ # then end of the string
- )
- /iox do
- %Q|<A HREF="#{$1}">#{$1}</A>|
- end
- print line
-end
-
-
-# @@PLEAC@@_6.23
-%r/^m*(d?c{0,3}|c[dm])(l?x{0,3}|x[lc])(v?i{0,3}|i[vx])$/i
-#-----------------------------
-str.sub!(/(\S+)(\s+)(\S+)/, '\3\2\1')
-#-----------------------------
-%r/(\w+)\s*=\s*(.*)\s*$/ # keyword is $1, value is $2
-#-----------------------------
-%r/.{80,}/
-#-----------------------------
-%r|(\d+)/(\d+)/(\d+) (\d+):(\d+):(\d+)|
-#-----------------------------
-str.gsub!(%r|/usr/bin|,'/usr/local/bin')
-#-----------------------------
-str.gsub!(/%([0-9A-Fa-f][0-9A-Fa-f])/){ $1.hex.chr }
-#-----------------------------
-str.gsub!(%r{
- /\* # Match the opening delimiter
- .*? # Match a minimal number of characters
- \*/ # Match the closing delimiter
-}xm,'')
-#-----------------------------
-str.sub!(/^\s+/, '')
-str.sub!(/\s+$/, '')
-
-# but really, in Ruby we'd just do:
-str.strip!
-#-----------------------------
-str.gsub!(/\\n/,"\n")
-#-----------------------------
-str.sub!(/^.*::/, '')
-#-----------------------------
-%r/^([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])\.
- ([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])$/x
-#-----------------------------
-str.sub!(%r|^.*/|, '')
-#-----------------------------
-cols = ( (ENV['TERMCAP'] || " ") =~ /:co#(\d+):/ ) ? $1 : 80;
-#-----------------------------
-name = " #{$0} #{ARGV}".gsub(%r| /\S+/|, ' ')
-#-----------------------------
-require 'rbconfig'
-include Config
-raise "This isn't Linux" unless CONFIG['target_os'] =~ /linux/i;
-#-----------------------------
-str.gsub!(%r/\n\s+/, ' ')
-#-----------------------------
-nums = str.scan(/(\d+\.?\d*|\.\d+)/)
-#-----------------------------
-capwords = str.scan(%r/(\b[^\Wa-z0-9_]+\b)/)
-#-----------------------------
-lowords = str.scan(%r/(\b[^\WA-Z0-9_]+\b)/)
-#-----------------------------
-icwords = str.scan(%r/(\b[^\Wa-z0-9_][^\WA-Z0-9_]*\b)/)
-#-----------------------------
-links = str.scan(%r/<A[^>]+?HREF\s*=\s*["']?([^'" >]+?)[ '"]?>/mi)
-#-----------------------------
-initial = str =~ /^\S+\s+(\S)\S*\s+\S/ ? $1 : ""
-#-----------------------------
-str.gsub!(%r/"([^"]*)"/, %q-``\1''-)
-#-----------------------------
-
-$/ = ""
-sentences = []
-ARGF.each do |para|
- para.gsub!(/\n/, ' ')
- para.gsub!(/ {3,}/,' ')
- sentences << para.scan(/(\S.*?[!?.])(?= |\Z)/)
-end
-
-#-----------------------------
-%r/(\d{4})-(\d\d)-(\d\d)/ # YYYY in $1, MM in $2, DD in $3
-#-----------------------------
-%r/ ^
- (?:
- 1 \s (?: \d\d\d \s)? # 1, or 1 and area code
- | # ... or ...
- \(\d\d\d\) \s # area code with parens
- | # ... or ...
- (?: \+\d\d?\d? \s)? # optional +country code
- \d\d\d ([\s\-]) # and area code
- )
- \d\d\d (\s|\1) # prefix (and area code separator)
- \d\d\d\d # exchange
- $
- /x
-#-----------------------------
-%r/\boh\s+my\s+gh?o(d(dess(es)?|s?)|odness|sh)\b/i
-#-----------------------------
-lines = []
-lines << $1 while input.sub!(/^([^\012\015]*)(\012\015?|\015\012?)/,'')
-
-
-# @@PLEAC@@_7.0
-# An IO object being Enumerable, we can use 'each' directly on it
-File.open("/usr/local/widgets/data").each { |line|
- puts line if line =~ /blue/
-}
-
-logfile = File.new("/var/log/rubylog.txt", "w")
-mysub($stdin, logfile)
-
-# The method IO#readline is similar to IO#gets
-# but throws an exception when it reaches EOF
-f = File.new("bla.txt")
-begin
- while (line = f.readline)
- line.chomp
- $stdout.print line if line =~ /blue/
- end
-rescue EOFError
- f.close
-end
-
-while $stdin.gets # reads from STDIN
- unless (/\d/)
- $stderr.puts "No digit found." # writes to STDERR
- end
- puts "Read: #{$_}" # writes to STDOUT
-end
-
-logfile = File.new("/tmp/log", "w")
-
-logfile.close
-
-# $defout (or its synonym '$>') is the destination of output
-# for Kernel#print, Kernel#puts, and family functions
-logfile = File.new("log.txt", "w")
-old = $defout
-$defout = logfile # switch to logfile for output
-puts "Countdown initiated ..."
-$defout = old # return to original output
-puts "You have 30 seconds to reach minimum safety distance."
-
-
-# @@PLEAC@@_7.1
-source = File.new(path, "r") # open file "path" for reading only
-sink = File.new(path, "w") # open file "path" for writing only
-
-source = File.open(path, File::RDONLY) # open file "path" for reading only
-sink = File.open(path, File::WRONLY) # open file "path" for writing only
-
-file = File.open(path, "r+") # open "path" for reading and writing
-file = File.open(path, flags) # open "path" with the flags "flags" (see examples below for flags)
-
-# open file "path" read only
-file = File.open(path, "r")
-file = File.open(path, File::RDONLY)
-
-# open file "path" write only, create it if it does not exist
-# truncate it to zero length if it exists
-file = File.open(path, "w")
-file = File.open(path, File::WRONLY|File::TRUNC|File::CREAT)
-file = File.open(path, File::WRONLY|File::TRUNC|File::CREAT, 0666) # with permission 0666
-
-# open file "path" write only, fails if file exists
-file = File.open(path, File::WRONLY|File::EXCL|File::CREAT)
-file = File.open(path, File::WRONLY|File::EXCL|File::CREAT, 0666)
-
-# open file "path" for appending
-file = File.open(path, "a")
-file = File.open(path, File::WRONLY|File::APPEND|File::CREAT)
-file = File.open(path, File::WRONLY|File::APPEND|File::CREAT, 0666)
-
-# open file "path" for appending only when file exists
-file = File.open(path, File::WRONLY|File::APPEND)
-
-# open file "path" for reading and writing
-file = File.open(path, "r+")
-file = File.open(path, File::RDWR)
-
-# open file for reading and writing, create a new file if it does not exist
-file = File.open(path, File::RDWR|File::CREAT)
-file = File.open(path, File::RDWR|File::CREAT, 0600)
-
-# open file "path" reading and writing, fails if file exists
-file = File.open(path, File::RDWR|File::EXCL|File::CREAT)
-file = File.open(path, File::RDWR|File::EXCL|File::CREAT, 0600)
-
-
-# @@PLEAC@@_7.2
-# No problem with Ruby since the filename doesn't contain characters with
-# special meaning; like Perl's sysopen
-File.open(filename, 'r')
-
-
-# @@PLEAC@@_7.3
-File.expand_path('~root/tmp')
-#=> "/root/tmp"
-File.expand_path('~rpcuser')
-#=> "/var/lib/nfs"
-
-# To expand ~/.. it explicitely needs the environment variable HOME
-File.expand_path('~/tmp')
-#=> "/home/gc/tmp"
-
-
-# @@PLEAC@@_7.4
-# The exception raised in Ruby reports the filename
-File.open('afile')
-
-
-# @@PLEAC@@_7.5
-# Standard Ruby distribution provides the following useful extension
-require 'tempfile'
-# With the Tempfile class, the file is automatically deleted on garbage
-# collection, so you won't need to remove it, later on.
-tf = Tempfile.new('tmp') # a name is required to create the filename
-
-# If you need to pass the filename to an external program you can use
-# File#path, but don't forget to File#flush in order to flush anything
-# living in some buffer somewhere.
-tf.flush
-system("/usr/bin/dowhatever #{tf.path}")
-
-fh = Tempfile.new('tmp')
-fh.sync = true # autoflushes
-10.times { |i| fh.puts i }
-fh.rewind
-puts 'Tmp file has: ', fh.readlines
-
-
-# @@PLEAC@@_7.6
-while (DATA.gets) do
- # process the line
-end
-__END__
-# your data goes here
-# __DATA__ doesn't exist in Ruby
-
-#CODE
-# get info about the script (size, date of last modification)
-kilosize = DATA.stat.size / 1024
-last_modif = DATA.stat.mtime
-puts "<P>Script size is #{kilosize}"
-puts "<P>Last script update: #{last_modif}"
-__END__
-# DO NOT REMOVE THE PRECEEDING LINE.
-# Everything else in this file will be ignored.
-#CODE
-
-
-# @@PLEAC@@_7.7
-while line = gets do
- # do something with line.
-end
-
-# or
-while gets do
- # do something with $_
-end
-
-# or more rubyish
-$stdun.each do |line|
- # do stuff with line
-end
-
-
-# ARGF may makes this more easy
-# this is skipped if ARGV.size==0
-ARGV.each do |filename|
- # closing and exception handling are done by the block
- open(filename) do |fd|
- fd.each do |line|
- # do stuff with line
- end
- end rescue abort("can't open %s" % filename)
-end
-
-# globbing is done in the Dir module
-ARGV = Dir["*.[Cch]"] if ARGV.empty?
-
-# note: optparse is the preferred way to handle this
-if (ARGV[0] == '-c')
- chop_first += 1
- ARGV.shift
-end
-
-
-# processing numerical options
-if ARGV[0] =~ /^-(\d+)$/
- columns = $1
- ARGV.shift
-end
-
-# again, better to use optparse:
-require 'optparse'
-nostdout = 0
-append = 0
-unbuffer = 0
-ignore_ints = 0
-ARGV.options do |opt|
- opt.on('-n') { nostdout +=1 }
- opt.on('-a') { append +=1 }
- opt.on('-u') { unbuffer +=1 }
- opt.on('-i') { ignore_ints +=1 }
- opt.parse!
-end or abort("usage: " + __FILE__ + " [-ainu] [filenames]")
-
-# no need to do undef $/, we have File.read
-str = File.read(ARGV[0])
-
-# again we have File.read
-str = File.read(ARGV[0])
-
-# not sure what this should do:
-# I believe open the file, print filename, lineno and line:
-ARGF.each_with_index do |line, idx|
- print ARGF.filename, ":", idx, ";", line
-end
-
-# print all the lines in every file passed via command line that contains login
-ARGF.each do |line|
- puts line if line =~ /login/
-end
-#
-# even this would fit
-#%ruby -ne "print if /f/" 2.log
-#
-
-ARGF.each { |l| puts l.downcase! }
-
-#------------------
-#!/usr/bin/ruby -p
-# just like perl's -p
-$_.downcase!
-#
-
-# I don't know who should I trust.
-# perl's version splits on \w+ while python's on \w.
-
-chunks = 0
-
-File.read(ARGV[0]).split.each do |word|
- next if word =~ /^#/
- break if ["__DATA__", "__END__"].member? word
- chunks += 1
-end
-
-print "Found ", chunks, " chunks\n"
-
-
-# @@PLEAC@@_7.8
-old = File.open(old_file)
-new = File.open(new_file, "w")
-while old.gets do
- # change $_, then...
- new.print $_
-end
-old.close
-new.close
-File.rename(old_file, "old.orig")
-File.rename(new_file, old_file)
-
-while old.gets do
- if $. == 20 then # we are at the 20th line
- new.puts "Extra line 1"
- new.puts "Extra line 2"
- end
- new.print $_
-end
-
-while old.gets do
- next if 20..30 # skip the 20th line to the 30th
- # Ruby (and Perl) permit to write if 20..30
- # instead of if (20 <= $.) and ($. <= 30)
- new.print $_
-end
-
-
-# @@PLEAC@@_7.9
-#% ruby -i.orig -pe 'FILTER COMMAND' file1 file2 file3 ...
-#
-#-----------------------------
-##!/usr/bin/ruby -i.orig -p
-# filter commands go here
-#-----------------------------
-
-#% ruby -pi.orig -e 'gsub!(/DATE/){Time.now)'
-
-# effectively becomes:
-ARGV << 'I'
-oldfile = ""
-while gets
- if ARGF.filename != oldfile
- newfile = ARGF.filename
- File.rename(newfile, newfile + ".orig")
- $stdout = File.open(newfile,'w')
- oldfile = newfile
- end
- gsub!(/DATE/){Time.now}
- print
-end
-$stdout = STDOUT
-#-----------------------------
-#% ruby -i.old -pe 'gsub!(%r{\bhisvar\b}, 'hervar')' *.[Cchy]
-
-#-----------------------------
-# set up to iterate over the *.c files in the current directory,
-# editing in place and saving the old file with a .orig extension
-$-i = '.orig' # set up -i mode
-ARGV.replace(Dir['*.[Cchy]'])
-while gets
- if $. == 1
- print "This line should appear at the top of each file\n"
- end
- gsub!(/\b(p)earl\b/i, '\1erl') # Correct typos, preserving case
- print
- ARGF.close if ARGF.eof
-end
-
-
-# @@PLEAC@@_7.10
-File.open('itest', 'r+') do |f| # open file for update
- lines = f.readlines # read into array of lines
- lines.each do |it| # modify lines
- it.gsub!(/foo/, 'QQQ')
- end
- f.pos = 0 # back to start
- f.print lines # write out modified lines
- f.truncate(f.pos) # truncate to new length
-end # file is automatically closed
-#-----------------------------
-File.open('itest', 'r+') do |f|
- out = ""
- f.each do |line|
- out << line.gsub(/DATE/) {Time.now}
- end
- f.pos = 0
- f.print out
- f.truncate(f.pos)
-end
-
-# @@PLEAC@@_7.11
-File.open('infile', 'r+') do |f|
- f.flock File::LOCK_EX
- # update file
-end
-#-----------------------------
-File::LOCK_SH # shared lock (for reading)
-File::LOCK_EX # exclusive lock (for writing)
-File::LOCK_NB # non-blocking request
-File::LOCK_UN # free lock
-#-----------------------------
-unless f.flock File::LOCK_EX | File::LOCK_NB
- warn "can't get immediate lock: blocking ..."
- f.flock File::LOCK_EX
-end
-#-----------------------------
-File.open('numfile', File::RDWR|File::CREAT) do |f|
- f.flock(File::LOCK_EX)
- num = f.gets.to_i || 0
- f.pos = 0
- f.truncate 0
- f.puts num + 1q
-end
-
-
-# @@PLEAC@@_7.12
-output_handle.sync = true
-# Please note that like in Perl, $stderr is already unbuffered
-#-----------------------------
-#!/usr/bin/ruby -w
-# seeme - demo stdio output buffering
-$stdout.sync = ARGV.size > 0
-print "Now you don't see it..."
-sleep 2
-puts "now you do"
-#-----------------------------
-$stderr.sync = true
-afile.sync = false
-#-----------------------------
-# assume 'remote_con' is an interactive socket handle,
-# but 'disk_file' is a handle to a regular file.
-remote_con.sync = true # unbuffer for clarity
-disk_file.sync = false # buffered for speed
-#-----------------------------
-require 'socket'
-sock = TCPSocket.new('www.ruby-lang.org', 80)
-sock.sync = true
-sock.puts "GET /en/ HTTP/1.0 \n\n"
-resp = sock.read
-print "DOC IS: #{resp}\n"
-
-
-# @@PLEAC@@_7.13
-#-----------------------------
-# assumes fh1, fh2, fh2 are oen IO objects
-nfound = select([$stdin, fh1, fh2, fh3], nil, nil, 0)
-nfound[0].each do |file|
- case file
- when fh1
- # do something with fh1
- when fh2
- # do something with fh2
- when fh3
- # do something with fh3
- end
-end
-#-----------------------------
-input_files = []
-# repeat next line for all in-files to poll
-input_files << fh1
-if nfound = select(input_files, nil, nil, 0)
- # input ready on files in nfound[0]
-end
-
-
-# @@PLEAC@@_8.0
-#-----------------------------
-# datafile is a file or IO object
-datafile.readlines.each { |line|
- line.chomp!
- size = line.length
- puts size
-}
-#-----------------------------
-datafile.readlines.each { |line|
- puts line.chomp!.length
-}
-#-----------------------------
-lines = datafile.readlines
-#-----------------------------
-whole_file = file.read
-#-----------------------------
-# ruby -040 -e 'word = gets; puts "First word is #{word}"'
-#-----------------------------
-# ruby -ne 'BEGIN { $/="%%\n" }; $_.chomp; puts $_ if( $_=~/Unix/i)' fortune.dat
-#-----------------------------
-handle.print "one", "two", "three" # "onetwothree"
-puts "Baa baa black sheep." # sent to $stdout
-#-----------------------------
-buffer = handle.read(4096)
-rv = buffer.length
-#-----------------------------
-handle.truncate(length)
-open("/tmp#{$$}.pid", 'w') { |handle| handle.truncate(length) }
-#-----------------------------
-pos = datafile.pos # tell is an alias of pos
-puts "I'm #{pos} bytes from the start of datafile"
-#-----------------------------
-logfile.seek(0, IO::SEEK_END)
-datafile.seek(pos) # IO::SEEK_SET is the default
-out.seek(-20, IO::SEEK_CUR)
-#-----------------------------
-written = datafile.syswrite(mystring)
-raise RunTimeError unless written == mystring.length
-block = infile.sysread(256) # no equivalent to perl offset parameter in sysread
-puts "only read #{block.length} bytes" if 256 != block.length
-#-----------------------------
-pos = handle.sysseek(0, IO::SEEK_CUR) # don't change position
-
-
-# @@PLEAC@@_8.1
-while (line = fh.gets)
- line.chomp!
- nextline = nil
- line.gsub!(/\\$/) { |match| nextline = fh.gets; '' }
- if (nextline != nil)
- line += nextline
- redo
- end
- # process full record in line here
-end
-#-----------------------------
-# DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) \
-# $(TEXINFOS) $(INFOS) $(MANS) $(DATA)
-# DEP_DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) \
-# $(TEXINFOS) $(INFO_DEPS) $(MANS) $(DATA) \
-# $(EXTRA_DIST)
-#-----------------------------
-line.gsub!(/\\\s*$/, '') {
- # as before
-}
-
-
-# @@PLEAC@@_8.2
-#-----------------------------
-count = `wc -l < #{filename}`
-fail "wc failed: #{$?}" if $? != 0
-count.chomp!
-#-----------------------------
-count = 0
-File.open(file, 'r') { |fh|
- count += 1 while fh.gets
-}
-# count now holds the number of lines read
-#-----------------------------
-count = 0
-while (chunk = file.sysread(2**16))
- count += chunk.count("\n")
-end rescue EOFError
-#-----------------------------
-File.open(filename,'r') { |fh|
- count += 1 while fh.gets
-}
-# count now holds the number of lines read
-#-----------------------------
-# As ruby doesn't quite have an equivalent to using a for
-# statement as in perl, I threw this in
-count = File.readlines(filename).size
-#-----------------------------
-1 while file.gets
-count = $.
-#-----------------------------
-$/ = ''
-open(filename, 'r') { |fh|
- 1 while fh.gets
- para_count = $.
-} rescue fail("can't open #{filename}: $!")
-#-----------------------------
-
-
-# ^^PLEAC^^_8.3
-#-----------------------------
-while (gets)
- split.each { |chunk|
- # do something with chunk
- }
-end
-#-----------------------------
-while (gets)
- gsub(/(\w[\w'-]*)/) { |word|
- # do something with word
- }
-end
-#-----------------------------
-# Make a word frequency count
-# normally hashes can be created using {} or just Hash.new
-# but we want the default value of an entry to be 0 instead
-# of nil. (nil can't be incremented)
-seen = Hash.new(0)
-while (gets)
- gsub(/(\w[\w'-]*)/) { |word|
- seen[word.downcase] += 1
- }
-end
-# output hash in a descending numeric sort of its values
-seen.sort { |a,b| b[1] <=> a[1] }.each do |k,v|
- printf("%5d %s\n", v, k )
-end
-
-#-----------------------------
-# Line frequency count
-seen = Hash.new(0)
-while (gets)
- seen[$_.downcase] += 1
-end
-seen.sort { |a,b| b[1] <=> a[1] }.each do |k,v|
- printf("%5d %s\n", v, k )
-end
-#-----------------------------
-
-
-# @@PLEAC@@_8.4
-#-----------------------------
-# instead of file handle FILE, we can just
-# use a string containing the filename
-File.readlines(file).each { |line|
- # do something with line
-}
-#-----------------------------
-File.readlines(file).reverse_each { |line|
- # do something with line
-}
-#-----------------------------
-# the variable lines might have been created
-# this way
-# lines = File.readlines(file)
-#
-# normally one would use the reverse_each, but
-# if you insist on using a numerical index to
-# iterate over the lines array...
-(lines.size - 1).downto(0) { |i|
- line = lines[i]
-}
-#-----------------------------
-# the second readlines argument is a the
-# record separator $/, just like perl, a blank
-# separator splits the records into paragraphs
-File.readlines(file, '').each { |paragraph|
- # do something with paragraph
- puts "->Paragraph #{paragraph}"
-}
-#-----------------------------
-
-
-# @@PLEAC@@_8.6
-
-$/ = "%\n";
-srand;
-
-File.open('/usr/share/fortune/humorists').each do |line|
- adage = line if rand($.) < 1
-end
-
-puts adage;
-
-
-# @@PLEAC@@_8.10
-begin
- fh = File.open(file, "r+")
- addr = fh.tell unless fh.eof while fh.gets
- fh.truncate(addr)
-rescue SystemCallError
- $stderr.puts "#$!"
-end
-
-
-# @@PLEAC@@_9.0
-entry = File.stat("/usr/bin/vi")
-entry = File.stat("/usr/bin")
-entry = File.stat(INFILE)
-
-entry = File.stat("/usr/bin/vi")
-ctime = entry.ctime
-size = entry.size
-
-f = File.open(filename, "r")
-
-## There is no -T equivalent in Ruby, but we can still test emptiness
-if test(?s, filename)
- puts "#{filename} doesn't have text in it."
- exit
-end
-
-Dir.new("/usr/bin").each do |filename|
- puts "Inside /usr/bin is something called #{filename}"
-end
-
-
-# @@PLEAC@@_9.1
-file = File.stat("filename")
-readtime, writetime = file.atime, file.mtime
-file.utime(readtime, writetime)
-
-SECONDS_PER_DAY = 60 * 60 * 24
-file = File.stat("filename")
-atime, mtime = file.atime, file.mtime
-
-atime -= 7 * SECONDS_PER_DAY
-mtime -= 7 * SECONDS_PER_DAY
-
-File.utime(atime, mtime, file)
-mtime = File.stat(file).mtime
-File.utime(Time.new, mtime, file)
-File.utime(Time.new, File.stat("testfile").mtime, file)
-
-#-----------------------------
-#!/usr/bin/ruby -w
-## uvi - vi a file without changing it's access times
-
-if ARGV.length != 1
- puts "usage: uvi filename"
- exit
-end
-file = ARGV[0]
-atime, mtime = File.stat(file).atime, File.stat(file).mtime
-system(ENV["EDITOR"] || "vi", file)
-File.utime(atime, mtime, file)
-#-----------------------------
-
-
-# @@PLEAC@@_9.2
-File.unlink(FILENAME)
-
-err_flg = false
-filenames.each do |file|
- begin
- File.unlink(file)
- rescue
- err_flg = $!
- end
-end
-err_flg and raise "Couldn't unlink all of #{filenames.join(" ")}: #{err_flg}"
-
-File.unlink(file)
-
-count = filenames.length
-filenames.each do |file|
- begin
- File.unlink(file)
- rescue
- count -= 1
- end
-end
-if count != filenames.length
- STDERR.puts "could only delete #{count} of #{filenames.length} files"
-end
-
-
-# @@PLEAC@@_9.3
-require "ftools"
-File.copy(oldfile, newfile)
-
-infile = File.open(oldfile, "r")
-outfile = File.open(newfile, "w")
-
-blksize = infile.stat.blksize
-# This doesn't handle partial writes or ^Z
-# like the Perl version does.
-while (line = infile.read(blksize))
- outfile.write(line)
-end
-
-infile.close
-outfile.close
-
-system("cp #{oldfile} #{newfile}") # unix
-system("copy #{oldfile} #{newfile}") # dos, vms
-
-require "ftools"
-File.copy("datafile.dat", "datafile.bak")
-File.move("datafile.new", "datafile.dat")
-
-
-# @@PLEAC@@_9.4
-$seen = {} # must use global var to be seen inside of method below
-
-def do_my_thing(filename)
- dev, ino = File.stat(filename).dev, File.stat(filename).ino
- unless $seen[[dev, ino]]
- # do something with $filename because we haven't
- # seen it before
- end
- $seen[[dev, ino]] = $seen[[dev, ino]].to_i + 1
-end
-
-files.each do |filename|
- dev, ino = File.stat(filename).dev, File.stat(filename).ino
- if !$seen.has_key?([dev, ino])
- $seen[[dev, ino]] = []
- end
- $seen[[dev, ino]].push(filename)
-end
-
-$seen.keys.sort.each do |devino|
- ino, dev = devino
- if $seen[devino].length > 1
- # $seen[devino] is a list of filenames for the same file
- end
-end
-
-
-# @@PLEAC@@_9.5
-Dir.open(dirname) do |dir|
- dir.each do |file|
- # do something with dirname/file
- puts file
- end
-end
-# Dir.close is automatic
-
-# No -T equivalent in Ruby
-
-dir.each do |file|
- next if file =~ /^\.\.?$/
- # ...
-end
-
-def plainfiles(dir)
- dh = Dir.open(dir)
- dh.entries.grep(/^[^.]/).
- map {|file| "#{dir}/#{file}"}.
- find_all {|file| test(?f, file)}.
- sort
-end
-
-
-# @@PLEAC@@_9.6
-list = Dir.glob("*.c")
-
-dir = Dir.open(path)
-files = dir.entries.grep(/\.c$/)
-dir.close
-
-files = Dir.glob("*.c")
-files = Dir.open(path).entries.grep(/\.[ch]$/i)
-
-dir = Dir.new(path)
-files = dir.entries.grep(/\.[ch]$/i)
-
-begin
- d = Dir.open(dir)
-rescue Errno::ENOENT
- raise "Couldn't open #{dir} for reading: #{$!}"
-end
-
-files = []
-d.each do |file|
- puts file
- next unless file =~ /\.[ch]$/i
-
- filename = "#{dir}/#{file}"
- # There is no -T equivalent in Ruby, but we can still test emptiness
- files.push(filename) if test(?s, filename)
-end
-
-dirs.entries.grep(/^\d+$/).
- map { |file| [file, "#{path}/#{file}"]} .
- select { |file| test(?d, file[1]) }.
- sort { |a,b| a[0] <=> b[0] }.
- map { |file| file[1] }
-
-
-# @@PLEAC@@_9.7
-require 'find'
-Find.find(dirlist) do |file|
- # do whatever
-end
-
-require 'find'
-argv = ARGV.empty? ? %w{.} : ARGV
-Find.find(*argv) do |file|
- print file, (test(?d, file) ? "/\n" : "\n")
-end
-
-require 'find'
-argv = ARGV.empty? ? %w{.} : ARGV
-sum = 0
-Find.find(*argv) do |file|
- size = test(?s, file) || 0
- sum += size
-end
-puts "#{argv.join(' ')} contains #{sum} bytes"
-
-require 'find'
-argv = ARGV.empty? ? %w{.} : ARGV
-saved_size, saved_name = -1, ""
-Find.find(*argv) do |file|
- size = test(?s, file) || 0
- next unless test(?f, file) && size > saved_size
- saved_size = size
- saved_name = file
-end
-puts "Biggest file #{saved_name} in #{argv.join(' ')} is #{saved_size}"
-
-require 'find'
-argv = ARGV.empty? ? %w{.} : ARGV
-age, name = nil
-Find.find(*argv) do |file|
- mtime = File.stat(file).mtime
- next if age && age > mtime
- age = mtime
- name = file
-end
-puts "#{name} #{age}"
-
-#-----------------------------
-#!/usr/bin/ruby -w
-# fdirs - find all directories
-require 'find'
-argv = ARGV.empty? ? %w{.} : ARGV
-File.find(*argv) { |file| puts file if test(?d, file) }
-#-----------------------------
-
-
-# @@PLEAC@@_9.8
-require 'fileutils'
-
-puts "Usage #{$0} dir ..." if ARGV.empty?
-ARGV.each do |dir|
- FileUtils.rmtree(dir)
-end
-
-
-# @@PLEAC@@_9.9
-require 'ftools'
-names.each do |file|
- newname = file
- begin
- File.move(file, newname)
- rescue Errno::EPERM
- $stderr.puts "Couldn't rename #{file} to #{newname}: #{$!}"
- end
-end
-
-require 'ftools'
-op = ARGV.empty? ? (raise "Usage: rename expr [files]\n") : ARGV.shift
-argv = ARGV.empty? ? $stdin.readlines.map { |f| f.chomp } : ARGV
-argv.each do |file|
- was = file
- file = eval("file.#{op}")
- File.move(was, file) unless was == file
-end
-
-
-# @@PLEAC@@_9.10
-base = File.basename(path)
-dir = File.dirname(path)
-# ruby has no fileparse equivalent
-dir, base = File.split(path)
-ext = base.scan(/\..*$/).to_s
-
-path = '/usr/lib/libc.a'
-file = File.basename(path)
-dir = File.dirname(path)
-
-puts "dir is #{dir}, file is #{file}"
-# dir is /usr/lib, file is libc.a
-
-path = '/usr/lib/libc.a'
-dir, filename = File.split(path)
-name, ext = filename.split(/(?=\.)/)
-puts "dir is #{dir}, name is #{name}, ext is #{ext}"
-# NOTE: The Ruby code prints
-# dir is /usr/lib, name is libc, extension is .a
-# while the Perl code prints a '/' after the directory name
-# dir is /usr/lib/, name is libc, extension is .a
-
-# No fileparse_set_fstype() equivalent in ruby
-
-def extension(path)
- ext = path.scan(/\..*$/).to_s
- ext.sub(/^\./, "")
-end
-
-
-# @@PLEAC@@_9.11
-#-----------------------------
-#!/usr/bin/ruby -w
-# symirror - build spectral forest of symlinks
-
-require 'find'
-require 'fileutils'
-
-raise "usage: #{$0} realdir mirrordir" unless ARGV.size == 2
-
-srcdir,dstdir = ARGV
-srcmode = File::stat(srcdir).mode
-Dir.mkdir(dstdir, srcmode & 07777) unless test(?d, dstdir)
-
-# fix relative paths
-Dir.chdir(srcdir) {srcdir = Dir.pwd}
-Dir.chdir(dstdir) {dstdir = Dir.pwd}
-
-Find.find(srcdir) do |srcfile|
- if test(?d, srcfile)
- dest = srcfile.sub(/^#{srcdir}/, dstdir)
- dmode = File::stat(srcfile).mode & 07777
- Dir.mkdir(dest, dmode) unless test(?d, dest)
- a = Dir["#{srcfile}/*"].reject{|f| test(?d, f)}
- FileUtils.ln_s(a, dest)
- end
-end
-
-
-# @@PLEAC@@_9.12
-# we use the Getopt/Declare library here for convenience:
-# http://raa.ruby-lang.org/project/getoptdeclare/
-#-----------------------------
-#!/usr/bin/ruby -w
-# lst - list sorted directory contents (depth first)
-
-require 'find'
-require 'etc'
-require "Getopt/Declare"
-
-# Note: in the option-spec below there must by at least one hard
-# tab in between each -option and its description. For example
-# -i <tab> read from stdin
-
-opts = Getopt::Declare.new(<<'EOPARAM')
- ============
- Input Format:
- -i read from stdin
- ============
- Output Format:
- -l long listing
- -r reverse listing
- ============
- Sort on: (one of)
- -m mtime (modify time - default)
- {$sort_criteria = :mtime}
- -u atime (access time)
- {$sort_criteria = :atime}
- -c ctime (inode change time)
- {$sort_criteria = :ctime}
- -s size
- {$sort_criteria = :size}
- [mutex: -m -u -c -s]
-
-EOPARAM
-
-$sort_criteria ||= :mtime
-files = {}
-DIRS = opts['-i'] ? $stdin.readlines.map{|f|f.chomp!} : ARGV
-DIRS.each do |dir|
- Find.find(dir) do |ent|
- files[ent] = File::stat(ent)
- end
-end
-entries = files.keys.sort_by{|f| files[f].send($sort_criteria)}
-entries = entries.reverse unless opts['-r']
-
-entries.each do |ent|
- unless opts['-l']
- puts ent
- next
- end
- stats = files[ent]
- ftime = stats.send($sort_criteria == :size ? :mtime : $sort_criteria)
- printf "%6d %04o %6d %8s %8s %8d %s %s\n",
- stats.ino,
- stats.mode & 07777,
- stats.nlink,
- ETC::PASSWD[stats.uid].name,
- ETC::GROUP[stats.gid].name,
- stats.size,
- ftime.strftime("%a %b %d %H:%M:%S %Y"),
- ent
-end
-
-
-# @@PLEAC@@_10.0
-def hello
- $greeted += 1 # in Ruby, a variable beginning with $ is global (can be any type of course)
- puts "hi there!"
-end
-
-# We need to initialize $greeted before it can be used, because "+=" is waiting a Numeric object
-$greeted = 0
-hello # note that appending () is optional to function calls with no parameters
-
-
-# @@PLEAC@@_10.1
-# In Ruby, parameters are named anyway
-def hypotenuse(side1, side2)
- Math.sqrt(side1**2 + side2**2) # the sqrt function comes from the Math module
-end
-diag = hypotenuse(3, 4)
-
-puts hypotenuse(3, 4)
-
-a = [3, 4]
-print hypotenuse(*a) # the star operator will magically convert an Array into a "tuple"
-
-both = men + women
-
-# In Ruby, all objects are references, so the same problem arises; we then return a new object
-nums = [1.4, 3.5, 6.7]
-def int_all(n)
- n.collect { |v| v.to_i }
-end
-ints = int_all(nums)
-
-nums = [1.4, 3.5, 6.7]
-def trunc_em(n)
- n.collect! { |v| v.to_i } # the bang-version of collect modifies the object
-end
-trunc_em(nums)
-
-# Ruby has two chomp version:
-# ``chomp'' chomps the record separator and returns what's expected
-# ``chomp!'' does the same but also modifies the parameter object
-
-
-# @@PLEAC@@_10.2
-def somefunc
- variable = something # variable is local by default
-end
-
-name, age = ARGV
-start = fetch_time
-
-a, b = pair # will succeed if pair is an Array object (like ARGV is)
-c = fetch_time
-
-# In ruby, run_check can't access a, b, or c until they are
-# explicitely defined global (using leading $), even if they are
-# both defined in the same scope
-
-def check_x(x)
- y = "whatever"
- run_check
- if $condition
- puts "got $x"
- end
-end
-
-# The following will keep a reference to the array, though the
-# results will be slightly different from perl: the last element
-# of $global_array will be itself an array
-def save_array(ary)
- $global_array << ary
-end
-
-# The following gives the same results as in Perl for $global_array,
-# though it doesn't illustrate anymore the way to keep a reference
-# to an object: $global_array is extended with the elements of ary
-def save_array(ary)
- $global_array += ary
-end
-
-
-# @@PLEAC@@_10.3
-# In Ruby, AFAIK a method cannot access "local variables" defined
-# upper scope; mostly because everything is an object, so you'll
-# do the same by defining an attribute or a static attribute
-
-# In Ruby the BEGIN also exists:
-BEGIN { puts "hello from BEGIN" }
-puts "hello from main"
-BEGIN { puts "hello from 2nd BEGIN" }
-# gives:
-# hello from BEGIN
-# hello from 2nd BEGIN
-# hello from main
-
-# In Ruby, it can be written as a static method and a static
-# variable
-class Counter
- @@counter = 0
- def Counter.next_counter; @@counter += 1; end
-end
-
-# There is no need of BEGIN since the variable will get
-# initialized when parsing
-class Counter
- @@counter = 42
- def Counter.next_counter; @@counter += 1; end
- def Counter.prev_counter; @@counter -= 1; end
-end
-
-
-# @@PLEAC@@_10.4
-# You can either get the whole trace as an array of strings, each
-# string telling which file, line and method is calling:
-caller
-
-# ...or only the last caller
-caller[0]
-
-# We need to extract just the method name of the backtrace:
-def whoami; caller()[0] =~ /in `([^']+)'/ ? $1 : '(anonymous)'; end
-def whowasi; caller()[1] =~ /in `([^']+)'/ ? $1 : '(anonymous)'; end
-
-
-# @@PLEAC@@_10.5
-# In Ruby, every value is a reference on an object, thus there is
-# no such problem
-array_diff(array1, array2)
-
-def add_vecpair(a1, a2)
- results = []
- a1.each_index { |i| results << (a1[i] + a2[i]) }
- results
-end
-a = [1, 2]
-b = [5, 8]
-c = add_vecpair(a, b)
-p c
-
-# Add this to the beginning of the function to check if we were
-# given two arrays
-a1.type == Array && a2.type == Array or
- raise "usage: add_vecpair array1 array2 (was used with: #{a1.type} #{a2.type})"
-
-
-# @@PLEAC@@_10.6
-# There is no return context in Ruby
-
-
-# @@PLEAC@@_10.7
-# Like in Perl, we need to fake with a hash, but it's dirty :-(
-def thefunc(param_args)
- args = { 'INCREMENT' => '10s', 'FINISH' => '0', 'START' => 0 }
- args.update(param_args)
- if (args['INCREMENT'] =~ /m$/ )
- # .....
- end
-end
-
-thefunc({ 'INCREMENT' => '20s', 'START' => '+5m', 'FINISH' => '+30m' })
-thefunc({})
-
-
-# @@PLEAC@@_10.8
-# there is no "undef" direct equivalent but there is the slice equiv:
-a, c = func.indexes(0, 2)
-
-
-# @@PLEAC@@_10.9
-# Ruby has no such limitation:
-def somefunc
- ary = []
- hash = {}
- # ...
- return ary, hash
-end
-arr, dict = somefunc
-
-array_of_hashes = fn
-h1, h2, h3 = fn
-
-
-# @@PLEAC@@_10.10
-return
-# or (equivalent)
-return nil
-
-
-# @@PLEAC@@_10.11
-# You can't prototype in Ruby regarding types :-(
-# Though, you can force the number of arguments:
-def func_with_no_arg; end
-def func_with_no_arg(); end
-def func_with_one_arg(a1); end
-def func_with_two_args(a1, a2); end
-def func_with_any_number_of_args(*args); end
-
-
-# @@PLEAC@@_10.12
-raise "some message" # raise exception
-
-begin
- val = func
-rescue Exception => msg
- $stderr.puts "func raised an exception: #{msg}"
-end
-
-# In Ruby the rescue statement uses an exception class, every
-# exception which is not matched is still continuing
-begin
- val = func
-rescue FullMoonError
- ...
-end
-
-
-# @@PLEAC@@_10.13
-# Saving Global Values
-# Of course we can just save the value and restore it later:
-def print_age
- puts "Age is #{$age}"
-end
-
-$age = 18 # global variable
-print_age()
-if condition
- safeage = $age
- $age = 23
- print_age()
- $age = safeage
-end
-
-# We can also use a method that saves the global variable and
-# restores it automatically when the block is left:
-
-def local(var)
- eval("save = #{var.id2name}")
- begin
- result = yield
- ensure
- # we want to call this even if we got an exception
- eval("#{var.id2name} = save")
- end
- result
-end
-
-condition = true
-$age = 18
-print_age()
-if condition
- local(:$age) {
- $age = 23
- print_age()
- }
-end
-print_age()
-
-# There is no need to use local() for filehandles or directory
-# handles in ruby because filehandles are normal objects.
-
-
-# @@PLEAC@@_10.14
-# In Ruby you may redefine a method [but not overload it :-(]
-# just by defining again with the same name.
-def foo; puts 'foo'; end
-def foo; puts 'bar'; end
-foo
-#=> bar
-
-# You can also take a reference to an existing method before
-# redefining a new one, using the `alias' keyword
-def foo; puts 'foo'; end
-alias foo_orig foo
-def foo; puts 'bar'; end
-foo_orig
-foo
-#=> foo
-#=> bar
-
-# AFAIK, there is no direct way to create a new method whose name
-# comes from a variable, so use "eval"
-colors = %w(red blue green yellow orange purple violet)
-colors.each { |c|
- eval <<-EOS
- def #{c}(*a)
- "<FONT COLOR='#{c}'>" + a.to_s + "</FONT>"
- end
- EOS
-}
-
-
-# @@PLEAC@@_10.15
-def method_missing(name, *args)
- "<FONT COLOR='#{name}'>" + args.join(' ') + "</FONT>"
-end
-puts chartreuse("stuff")
-
-
-# @@PLEAC@@_10.16
-def outer(arg)
- x = arg + 35
- inner = proc { x * 19 }
- x + inner.call()
-end
-
-
-# @@PLEAC@@_10.17
-#!/usr/bin/ruby -w
-# mailsort - sort mbox by different criteria
-require 'English'
-require 'Date'
-
-# Objects of class Mail represent a single mail.
-class Mail
- attr_accessor :no
- attr_accessor :subject
- attr_accessor :fulltext
- attr_accessor :date
-
- def initialize
- @fulltext = ""
- @subject = ""
- end
-
- def append(para)
- @fulltext << para
- end
-
- # this is called if you call puts(mail)
- def to_s
- @fulltext
- end
-end
-
-# represents a list of mails.
-class Mailbox < Array
-
- Subjectpattern = Regexp.new('Subject:\s*(?:Re:\s*)*(.*)\n')
- Datepattern = Regexp.new('Date:\s*(.*)\n')
-
- # reads mails from open file and stores them
- def read(file)
- $INPUT_RECORD_SEPARATOR = '' # paragraph reads
- msgno = -1
- file.each { |para|
- if para =~ /^From/
- mail = Mail.new
- mail.no = (msgno += 1)
- md = Subjectpattern.match(para)
- if md
- mail.subject = md[1]
- end
- md = Datepattern.match(para)
- if md
- mail.date = DateTime.parse(md[1])
- else
- mail.date = DateTime.now
- end
- self.push(mail)
- end
- mail.append(para) if mail
- }
- end
-
- def sort_by_subject_and_no
- self.sort_by { |m|
- [m.subject, m.no]
- }
- end
-
- # sorts by a list of attributs of mail, given as symbols
- def sort_by_attributs(*attrs)
- # you can sort an Enumerable by an array of
- # values, they would be compared
- # from ary[0] to ary[n]t, say:
- # ['b',1] > ['a',10] > ['a',9]
- self.sort_by { |elem|
- attrs.map { |attr|
- elem.send(attr)
- }
- }
- end
-
-end
-
-mailbox = Mailbox.new
-mailbox.read(ARGF)
-
-# print only subjects sorted by subject and number
-for m in mailbox.sort_by_subject_and_no
- puts(m.subject)
-end
-
-# print complete mails sorted by date, then subject, then number
-for m in mailbox.sort_by_attributs(:date, :subject)
- puts(m)
-end
-
-
-# @@PLEAC@@_11.7
-def mkcounter(count)
- start = count
- bundle = {
- "NEXT" => proc { count += 1 },
- "PREV" => proc { count -= 1 },
- "RESET" => proc { count = start }
- }
- bundle["LAST"] = bundle["PREV"]
- return bundle
-end
-
-c1 = mkcounter(20)
-c2 = mkcounter(77)
-
-puts "next c1: #{c1["NEXT"].call}" # 21
-puts "next c2: #{c2["NEXT"].call}" # 78
-puts "next c1: #{c1["NEXT"].call}" # 22
-puts "last c1: #{c1["PREV"].call}" # 21
-puts "last c1: #{c1["LAST"].call}" # 20
-puts "old c2: #{c2["RESET"].call}" # 77
-
-
-# @@PLEAC@@_11.15
-class Binary_tree
- def initialize(val)
- @value = val
- @left = nil
- @right = nil
- end
-
- # insert given value into proper point of
- # provided tree. If no tree provided,
- # use implicit pass by reference aspect of @_
- # to fill one in for our caller.
- def insert(val)
- if val < @value then
- if @left then
- @left.insert(val)
- else
- @left = Binary_tree.new(val)
- end
- elsif val > @value then
- if @right then
- @right.insert(val)
- else
- @right = Binary_tree.new(val)
- end
- else
- puts "double"
- # do nothing, no double values
- end
- end
-
- # recurse on left child,
- # then show current value,
- # then recurse on right child.
- def in_order
- @left.in_order if @left
- print @value, " "
- @right.in_order if @right
- end
-
- # show current value,
- # then recurse on left child,
- # then recurse on right child.
- def pre_order
- print @value, " "
- @left.pre_order if @left
- @right.pre_order if @right
- end
-
- # recurse on left child,
- # then recurse on right child,
- # then show current value.
- def post_order
- @left.post_order if @left
- @right.post_order if @right
- print @value, " "
- end
-
- # find out whether provided value is in the tree.
- # if so, return the node at which the value was found.
- # cut down search time by only looking in the correct
- # branch, based on current value.
- def search(val)
- if val == @value then
- return self
- elsif val < @value then
- return @left.search(val) if @left
- return nil
- else
- return @right.search(val) if @right
- return nil
- end
- end
-end
-
-# first generate 20 random inserts
-test = Binary_tree.new(0)
-for a in 0..20
- test.insert(rand(1000))
-end
-
-# now dump out the tree all three ways
-print "Pre order: "; test.pre_order; puts ""
-print "In order: "; test.in_order; puts ""
-print "Post order: "; test.post_order; puts ""
-
-print "search?"
-while gets
- print test.search($_.to_i)
- print "\nsearch?"
-end
-
-
-# @@PLEAC@@_12.0
-# class and module names need to have the first letter capitalized
-module Alpha
- NAME = 'first'
-end
-module Omega
- NAME = 'last'
-end
-puts "Alpha is #{Alpha::NAME}, Omega is #{Omega::NAME}"
-
-# ruby doesn't differentiate beteen compile-time and run-time
-require 'getoptlong.rb'
-require 'getoptlong' # assumes the .rb
-require 'cards/poker.rb'
-require 'cards/poker' # assumes the .rb
-load 'cards/poker' # require only loads the file once
-
-module Cards
- module Poker
- @card_deck = Array.new # or @card_deck = []
- def shuffle
- end
- end
-end
-
-
-# @@PLEAC@@_12.1
-# a module exports all of its functions
-module Your_Module
- def self.function
- # this would be called as Your_Module.function
- end
-
- def Your_Module.another
- # this is the same as above, but more specific
- end
-end
-
-# @@PLEAC@@_12.2
-begin
- require 'nonexistent'
-rescue LoadError
- puts "Couldn't load #{$!}" # $! contains the last error string
-end
-
-# @@PLEAC@@_12.4
-# module variables are private unless access functions are defined
-module Alpha
- @aa = 10
- @bb = 11
-
- def self.put_aa
- puts @aa
- end
-
- def self.bb=(val)
- @bb = val
- end
-end
-
-Alpha.bb = 12
-# Alpha.aa = 10 # error, no aa=method
-
-
-# @@PLEAC@@_12.5
-# caller provides a backtrace of the call stack
-module MyModule
- def find_caller
- caller
- end
-
- def find_caller2(i)
- caller(i) # an argument limits the size of the stack returned
- end
-end
-
-
-# @@PLEAC@@_12.6
-BEGIN {
- $logfile = '/tmp/mylog' unless defined? $logfile
- $LF = File.open($logfile, 'a')
-}
-
-module Logger
- def self.logmsg(msg)
- $LF.puts msg
- end
-
- logmsg('startup')
-end
-
-END {
- Logger::logmsg('shutdown')
- $LF.close
-}
-
-
-# @@PLEAC@@_12.7
-#-----------------------------
-# results may be different on your system
-# % ruby -e "$LOAD_PATH.each_index { |i| printf("%d %s\n", i, $LOAD_PATH[i] }
-#0 /usr/local/lib/site_ruby/1.6
-#1 /usr/local/lib/site_ruby/1.6/i386-linux
-#2 /usr/local/lib/site_ruby/
-#3 /usr/lib/ruby/1.6
-#4 /usr/lib/ruby/1.6/i136-linux
-#5 .
-#-----------------------------
-# syntax for sh, bash, ksh, or zsh
-#$ export RUBYLIB=$HOME/rubylib
-
-# syntax for csh or tcsh
-# % setenv RUBYLIB ~/rubylib
-#-----------------------------
-$LOAD_PATH.unshift "/projects/spectre/lib";
-
-
-# @@PLEAC@@_12.8
-# equivalents in ruby are mkmf, SWIG, or Ruby/DL depending on usage
-
-
-# @@PLEAC@@_12.9
-# no equivalent in ruby
-
-
-# @@PLEAC@@_12.10
-# no equivalent in ruby
-
-
-# @@PLEAC@@_12.11
-module FineTime
- def self.time
- # to be defined later
- end
-end
-
-
-module FineTime
- def self.time
- "its a fine time"
- end
-end
-
-puts FineTime.time #=> "its a fine time"
-
-
-# @@PLEAC@@_12.12
-def even_only(n)
- raise "#{n} is not even" if (n & 1) != 0 # one way to test
- # ...
-end
-def even_only(n)
- $stderr.puts "#{n} is not even" if (n & 1) != 0
- # ...
-end
-
-
-# @@PLEAC@@_12.17
-# The library archive for ruby is called Ruby Application archive,
-# or shorter RAA, and can be found at http://raa.ruby-lang.org.
-# A typical library is installed like this:
-# % gunzip some-module-4.54.tar.gz
-# % tar xf some-module-4.54.tar
-# % cd some-module-4.54.tar
-# % ruby install.rb config
-# % ruby install.rb setup
-# get superuser previleges here if needed for next step
-# % ruby install.rb install
-
-# Some modules use a different process,
-# you should find details in the documentation
-# Here is an example of such a different process
-# % ruby extconf.rb
-# % make
-# % make install
-
-# If you want the module installed in your own directory:
-# For ruby version specific libraries
-# % ruby install.rb config --site-ruby=~/lib
-# For version independent libraries
-# % ruby install.rb config --site-ruby-common=~/lib
-
-# Information about possible options for config
-# % ruby install.rb --help
-
-# If you have your own complete distribution
-# % ruby install.rb --prefix=path=~/ruby-private
-
-
-# @@PLEAC@@_13.0
-# Classes and objects in Ruby are rather straigthforward
-class Person
- # Class variables (also called static attributes) are prefixed by @@
- @@person_counter=0
-
- # object constructor
- def initialize(age, name, alive = true) # Default arg like in C++
- @age, @name, @alive = age, name, alive # Object attributes are prefixed by '@'
- @@person_counter += 1
- # There is no '++' operator in Ruby. The '++'/'--' operators are in fact
- # hidden assignments which affect variables, not objects. You cannot accomplish
- # assignment via method. Since everything in Ruby is object, '++' and '--'
- # contradict Ruby OO ideology. Instead '-=' and '+=' are used.
- end
-
- attr_accessor :name, :age # This creates setter and getter methods for @name
- # and @age. See 13.3 for detailes.
-
- # methods modifying the receiver object usually have the '!' suffix
- def die!
- @alive = false
- puts "#{@name} has died at the age of #{@age}."
- @alive
- end
-
- def kill(anotherPerson)
- print @name, ' is killing ', anotherPerson.name, ".\n"
- anotherPerson.die!
- end
-
- # methods used as queries
- # usually have the '?' suffix
- def alive?
- @alive && true
- end
-
- def year_of_birth
- Time.now.year - @age
- end
-
- # Class method (also called static method)
- def Person.number_of_people
- @@person_counter
- end
-end
-
-# Using the class:
-# Create objects of class Person
-lecter = Person.new(47, 'Hannibal')
-starling = Person.new(29, 'Clarice', true)
-pazzi = Person.new(40, 'Rinaldo', true)
-
-# Calling a class method
-print "There are ", Person.number_of_people, " Person objects\n"
-
-print pazzi.name, ' is ', (pazzi.alive?) ? 'alive' : 'dead', ".\n"
-lecter.kill(pazzi)
-print pazzi.name, ' is ', (pazzi.alive?) ? 'alive' : 'dead', ".\n"
-
-print starling.name , ' was born in ', starling.year_of_birth, "\n"
-
-
-# @@PLEAC@@_13.1
-# If you don't need any initialisation in the constructor,
-# you don't need to write a constructor.
-class MyClass
-end
-
-class MyClass
- def initialize
- @start = Time.new
- @age = 0
- end
-end
-
-class MyClass
- def initialize(inithash)
- @start = Time.new
- @age = 0
- for key, value in inithash
- instance_variable_set("@#{key}", value)
- end
- end
-end
-
-# @@PLEAC@@_13.2
-# Objects are destroyed by the garbage collector.
-# The time of destroying is not predictable.
-# The ruby garbage collector can handle circular references,
-# so there is no need to write destructor for that.
-
-# There is no direct support for destructor.
-# You can call a custom function, or more specific a proc object, when the
-# garbage collector is about to destruct the object, but it is unpredictable
-# when this occurs.
-# Also if such a finalizer object has a reference to the orignal object,
-# this may prevent the original object to get garbage collected.
-# Because of this problem the finalize method below is
-# a class method and not a instance method.
-# So if you need to free resources for an object, like
-# closing a socket or kill a spawned subprocess,
-# you should do it explicitly.
-
-class MyClass
- def initialize
- ObjectSpace.define_finalizer(self,
- self.class.method(:finalize).to_proc)
- end
- def MyClass.finalize(id)
- puts "Object #{id} dying at #{Time.new}"
- end
-end
-
-# test code
-3.times {
- MyClass.new
-}
-ObjectSpace.garbage_collect
-
-
-# @@PLEAC@@_13.3
-# You can write getter and setter methods in a natural way:
-class Person
- def name
- @name
- end
- def name=(name)
- @name = name
- end
-end
-
-# But there is a better and shorter way
-class Person
- attr_reader :age
- attr_writer :name
- # attr_reader and attr_writer are actually methods in class Class
- # which set getter and setter methods for you.
-end
-
-# There is also attr_accessor to create both setters and getters
-class Person
- attr_accessor :age, :name
-end
-
-
-# @@PLEAC@@_13.4
-class Person
- # Class variables (also called static attributes) are prefixed by @@
- @@person_counter = 0
-
- def Person.population
- @@person_counter
- end
- def initialize
- @@person_counter += 1
- ObjectSpace.define_finalizer(self,
- self.class.method(:finalize).to_proc)
- end
- def Person.finalize(id)
- @@person_counter -= 1
- end
-end
-people = []
-10.times {
- people.push(Person.new)
-}
-printf("There are %d people alive", Person.population)
-
-
-FixedArray.class_max_bounds = 100
-alpha = FixedArray.new
-puts "Bound on alpha is #{alpha.max_bounds}"
-
-beta = FixedArray.new
-beta.max_bounds = 50 # calls the instance method
-beta.class.class_max_bounds = 50 # alternative, calls the class method
-puts "Bound on alpha is #{alpha.max_bounds}"
-
-class FixedArray
- @@bounds = 7
-
- def max_bounds
- @@max_bounds
- end
- # instance method, which sets the class variable
- def max_bounds=(value)
- @@max_bounds = value
- end
- # class method. This can only be called on a class,
- # but not on the instances
- def FixedArray.class_max_bounds=(value)
- @@max_bounds = value
- end
-end
-
-
-# @@PLEAC@@_13.5
-PersonStruct = Struct.new("Person", :name, :age, :peers)
-# creates a class "Person::Struct", which is accessiable with the
-# constant "PersonStruct"
-p = PersonStruct.new
-p = Struct::Person.new # alternative using the classname
-p.name = "Jason Smythe"
-p.age = 13
-p.peers = ["Wilbur", "Ralph", "Fred"]
-p[:peers] = ["Wilbur", "Ralph", "Fred"] # alternative access using symbol
-p["peers"] = ["Wilbur", "Ralph", "Fred"] # alternative access using name of field
-p[2] = ["Wilbur", "Ralph", "Fred"] # alternative access using index of field
-puts "At age #{p.age}, #{p.name}'s first friend is #{p.peers[0]}"
-
-# The fields of a struct have no special type, like other ruby variables
-# you can put any objects in. Therefore the discussions how to specify
-# the types of the fields do not apply to ruby.
-
-FamilyStruct = Struct.new("Family", :head, :address, :members)
-folks = FamilyStruct.new
-folks.head = PersonStruct.new
-dad = folks.head
-dad.name = "John"
-dad.age = 34
-
-# supply of own accessor method for the struct for error checking
-class PersonStruct
- def age=(value)
- if !value.kind_of?(Integer)
- raise(ArgumentError, "Age #{value} isn't an Integer")
- elsif value > 150
- raise(ArgumentError, "Age #{value} is unreasonable")
- end
- @age = value
- end
-end
-
-
-# @@PLEAC@@_13.6
-# The ruby Object class defines a dup and a clone method.
-# The dup method is recommended for prototype object creation.
-# The default implementation makes a shallow copy,
-# but each class can override it, for example to make a deep copy.
-
-# If you want to call 'new' directly on the instances,
-# you can create a instance method "new", which returns a new duplicate.
-# This method is distinct from the class method new.
-#
-class A
- def new
- dup
- end
-end
-
-ob1 = A.new
-# later on
-ob2 = ob1.new
-
-
-# @@PLEAC@@_13.7
-methname = 'flicker'
-obj.send(methname, 10) # calls obj.flicker(10)
-
-# call three methods on the object, by name
-['start', 'run', 'stop'].each do |method_string|
- obj.send(method_string)
-end
-
-# Another way is to create a Method object
-method_obj = obj.method('flicker')
-# And then call it
-method_obj.call(10)
-
-
-# @@PLEAC@@_13.8
-# All classes in Ruby inherit from class Object
-# and thus all objects share methods defined in this class
-
-# the class of the object
-puts any_object.type
-
-# Ruby classes are actually objects of class Class and they
-# respond to methods defined in Object class as well
-
-# the superclass of this class
-puts any_object.class.superclass
-
-# ask an object whether it is an instance of particular class
-n = 4.7
-puts n.instance_of?(Float) # true
-puts n.instance_of?(Numeric) # false
-
-# ask an object whether it is an instance of class, one of the
-# superclasses of the object, or modules included in it
-puts n.kind_of?(Float) # true (the class)
-puts n.kind_of?(Numeric) # true (an ancestor class)
-puts n.kind_of?(Comparable) # true (a mixin module)
-puts n.kind_of?(String) # false
-
-# ask an object whether it can respond to a particular method
-puts n.respond_to?('+') # true
-puts n.respond_to?('length') # false
-
-# all methods an object can respond to
-'just a string'.methods.each { |m| puts m }
-
-
-# @@PLEAC@@_13.9
-# Actually any class in Ruby is inheritable
-class Person
- attr_accessor :age, :name
- def initialize
- @name
- @age
- end
-end
-#-----------------------------
-dude = Person.new
-dude.name = 'Jason'
-dude.age = 23
-printf "%s is age %d.\n", dude.name, dude.age
-#-----------------------------
-# Inheriting from Person
-class Employee < Person
- attr_accessor :salary
-end
-#-----------------------------
-empl = Employee.new
-empl.name = 'Jason'
-empl.age = 23
-empl.salary = 200
-printf "%s is age %d, the salary is %d.\n", empl.name, empl.age, empl.salary
-#-----------------------------
-# Any built-in class can be inherited the same way
-class WeirdString < String
- def initialize(obj)
- super obj
- end
- def +(anotherObj) # + method in this class is overridden
- # to return the sum of string lengths
- self.length + anotherObj.length # 'self' can be omitted
- end
-end
-#-----------------------------
-a = WeirdString.new('hello')
-b = WeirdString.new('bye')
-
-puts a + b # the overridden +
-#=> 8
-puts a.length # method from the superclass, String
-#=> 5
-
-
-# @@PLEAC@@_13.11
-# In ruby you can override the method_missing method
-# to have a solution similar to perls AUTOLOAD.
-class Person
-
- def initialize
- @ok_fields = %w(name age peers parent)
- end
-
- def valid_attribute?(name)
- @ok_fields.include?(name)
- end
-
- def method_missing(namesymbol, *params)
- name = namesymbol.to_s
- return if name =~ /^A-Z/
- if name.to_s[-1] == ('='[0]) # we have a setter
- isSetter = true
- name.sub!(/=$/, '')
- end
- if valid_attribute?(name)
- if isSetter
- instance_variable_set("@#{name}", *params)
- else
- instance_variable_get("@#{name}", *params)
- end
- else
- # if no annestor is responsible,
- # the Object class will throw a NoMethodError exception
- super(namesymbol, *params)
- end
- end
-
- def new
- kid = Person.new
- kid.parent = self
- kid
- end
-
-end
-
-dad = Person.new
-dad.name = "Jason"
-dad.age = 23
-kid = dad.new
-kid.name = "Rachel"
-kid.age = 2
-puts "Kid's parent is #{kid.parent.name}"
-puts dad
-puts kid
-
-class Employee < Person
- def initialize
- super
- @ok_fields.push("salary", "boss")
- end
- def ok_fields
- @ok_fields
- end
-end
-
-
-# @@PLEAC@@_13.13
-# The ruby garbage collector pretends to cope with circular structures.
-# You can test it with this code:
-class RingNode
- attr_accessor :next
- attr_accessor :prev
- attr_reader :name
-
- def initialize(aName)
- @name = aName
- ObjectSpace.define_finalizer(self,
- self.class.method(:finalize).to_proc)
- end
-
- def RingNode.finalize(id)
- puts "Node #{id} dying"
- end
-
- def RingNode.show_all_objects
- ObjectSpace.each_object {|id|
- puts id.name if id.class == RingNode
- }
- end
-end
-
-def create_test
- a = RingNode.new("Node A")
- b = RingNode.new("Node B")
- c = RingNode.new("Node C")
- a.next = b
- b.next = c
- c.next = a
- a.prev = c
- c.prev = b
- b.prev = a
-
- a = nil
- b = nil
- c = nil
-end
-
-create_test
-RingNode.show_all_objects
-ObjectSpace.garbage_collect
-puts "After garbage collection"
-RingNode.show_all_objects
-
-
-# @@PLEAC@@_13.14
-class String
- def <=>(other)
- self.casecmp other
- end
-end
-
-# There is no way to directly overload the '""' (stringify)
-# operator in Ruby. However, by convention, classes which
-# can reasonably be converted to a String will define a
-# 'to_s' method as in the TimeNumber class defined below.
-# The 'puts' method will automatcally call an object's
-# 'to_s' method as is demonstrated below.
-# Furthermore, if a class defines a to_str method, an object of that
-# class can be used most any place where the interpreter is looking
-# for a String value.
-
-#---------------------------------------
-# NOTE: Ruby has a builtin Time class which would usually be used
-# to manipulate time objects, the following is supplied for
-# educational purposes to demonstrate operator overloading.
-#
-class TimeNumber
- attr_accessor :hours,:minutes,:seconds
- def initialize( hours, minutes, seconds)
- @hours = hours
- @minutes = minutes
- @seconds = seconds
- end
-
- def to_s
- return sprintf( "%d:%02d:%02d", @hours, @minutes, @seconds)
- end
-
- def to_str
- to_s
- end
-
- def +( other)
- seconds = @seconds + other.seconds
- minutes = @minutes + other.minutes
- hours = @hours + other.hours
- if seconds >= 60
- seconds %= 60
- minutes += 1
- end
- if minutes >= 60
- minutes %= 60
- hours += 1
- end
- return TimeNumber.new(hours, minutes, seconds)
- end
-
- def -(other)
- raise NotImplementedError
- end
-
- def *(other)
- raise NotImplementedError
- end
-
- def /( other)
- raise NotImplementedError
- end
-end
-
-t1 = TimeNumber.new(0, 58, 59)
-sec = TimeNumber.new(0, 0, 1)
-min = TimeNumber.new(0, 1, 0)
-puts t1 + sec + min + min
-
-#-----------------------------
-# StrNum class example: Ruby's builtin String class already has the
-# capabilities outlined in StrNum Perl example, however the '*' operator
-# on Ruby's String class acts differently: It creates a string which
-# is the original string repeated N times.
-#
-# Using Ruby's String class as is in this example:
-x = "Red"; y = "Black"
-z = x+y
-r = z*3 # r is "RedBlackRedBlackRedBlack"
-puts "values are #{x}, #{y}, #{z}, and #{r}"
-print "#{x} is ", x < y ? "LT" : "GE", " #{y}\n"
-# prints:
-# values are Red, Black, RedBlack, and RedBlackRedBlackRedBlack
-# Red is GE Black
-
-#-----------------------------
-class FixNum
- REGEX = /(\.\d*)/
- DEFAULT_PLACES = 0
- attr_accessor :value, :places
- def initialize(value, places = nil)
- @value = value
- if places
- @places = places
- else
- m = REGEX.match(value.to_s)
- if m
- @places = m[0].length - 1
- else
- @places = DEFAULT_PLACES
- end
- end
- end
-
- def +(other)
- FixNum.new(@value + other.value, max(@places, other.places))
- end
-
- def *(other)
- FixNum.new(@value * other.value, max(@places, other.places))
- end
-
- def /(other)
- puts "Divide: #{@value.to_f/other.value.to_f}"
- result = FixNum.new(@value.to_f/other.value.to_f)
- result.places = max(result.places,other.places)
- result
- end
-
- def to_s
- sprintf("STR%s: %.*f", self.class.to_s , @places, @value) #.
- end
-
- def to_str
- to_s
- end
-
- def to_i #convert to int
- @value.to_i
- end
-
- def to_f #convert to float`
- @value.to_f
- end
-
- private
- def max(a,b)
- a > b ? a : b
- end
-end
-
-def demo()
- x = FixNum.new(40)
- y = FixNum.new(12, 0)
-
- puts "sum of #{x} and #{y} is #{x+y}"
- puts "product of #{x} and #{y} is #{x*y}"
-
- z = x/y
- puts "#{z} has #{z.places} places"
- unless z.places
- z.places = 2
- end
-
- puts "div of #{x} by #{y} is #{z}"
- puts "square of that is #{z*z}"
-end
-
-if __FILE__ == $0
- demo()
-end
-
-
-# @@PLEAC@@_14.1
-# There are dbm, sdbm, gdbm modules
-# and the bdb module for accessing the berkeley db
-# sdbm seem to be available on the most systems,
-# so we use it here
-#
-require "sdbm"
-SDBM.open("filename", 0666) { |dbobj|
- # raises exception if open error
-
- # the returned sdbm-dbobj has most of the methods of a hash
- v = dbobj["key"]
- dbobj["key"] = "newvalue"
- if dbobj.has_key?("key")
- # ...
- end
- dbobj.delete("key2")
-}
-# database is open only inside the block.
-
-# It is also possible to use a open .. close pair:
-dbobj = SDBM.open("filename", 0666)
-#.. do something with dbobj
-dbobj.close
-
-#!/usr/bin/ruby -w
-# userstats - generate statistics on who is logged in
-# call with usernames as argument to display the totals
-# for the given usernames, call with "ALL" to display all users
-
-require "sdbm"
-filename = '/tmp/userstats.db'
-SDBM.open(filename, 0666) { |dbobj|
- if ARGV.length > 0
- if ARGV[0] == "ALL"
- # ARGV is constant, so we need the variable userlist
- userlist = dbobj.keys().sort()
- else
- userlist = ARGV
- end
- userlist.each { |user|
- print "#{user}\t#{dbobj[user]}\n"
- }
- else
- who = `who`
- who.split("\n").each { |line|
- md = /^(\S+)/.match(line)
- raise "Bad line from who: #{line}" unless md
- # sdbm stores only strings, so "+=" doesn't work,
- # we need to convert them expicitly back to integer.
- if dbobj.has_key?(md[0])
- dbobj[md[0]] = dbobj[md[0]].to_i + 1
- else
- dbobj[md[0]] = "1"
- end
- }
- end
-}
-
-
-# @@PLEAC@@_14.2
-# using open and clear
-dbobj = SDBM.open("filename", 0666)
-dbobj.clear()
-dbobj.close()
-# deleting file and recreating it
-# the filenames depend on the flavor of dbm you use,
-# for example sdbm has two files named filename.pag and filename.dir,
-# so you need to delete both files
-begin
- File.delete("filename")
- # raises Exception if not exist
- dbobj = SDBM.open("filename", 0666)
-rescue
- # add error handling here
-end
-
-
-# @@PLEAC@@_14.3
-# sdbm2gdbm: converts sdbm database to a gdbm database
-require "sdbm"
-require "gdbm"
-
-unless ARGV.length == 2
- fail "usage: sdbm2gdbm infile outfile"
-end
-infile = ARGV[0]
-outfile = ARGV[1]
-
-sdb = SDBM.open(infile)
-gdb = GDBM.open(outfile, 0666)
-sdb.each { |key, val|
- gdb[key] = val
-}
-gdb.close
-sdb.close
-
-
-# @@PLEAC@@_14.4
-#!/usr/bin/ruby -w
-# dbmmerge: merges two dbm databases
-require "sdbm"
-
-unless ARGV.length == 3
- fail "usage: dbmmerge indb1 indb2 outdb"
-end
-infile1 = ARGV[0]
-infile2 = ARGV[0]
-outfile = ARGV[2]
-
-in1 = SDBM.open(infile1, nil)
-in2 = SDBM.open(infile2, nil)
-outdb = SDBM.open(outfile, 0666)
-
-[in1, in2].each { |indb|
- indb.each { |key, val|
- if outdb.has_key?(key)
- # decide which value to set.
- # set outdb[key] if necessary
- else
- outdb[key] = val
- end
- }
-}
-in1.close
-in2.close
-outdb.close
-
-
-# @@PLEAC@@_14.7
-# we write a tie method that extends the Array class.
-# It reads the file into the memory, executes the code block
-# in which you can manipulate the array as needed, and writes
-# the array back to the file after the end of the block execution
-class Array
- def tie(filename, flags)
- File.open(filename, flags) { |f|
- f.each_line { |line|
- self.push(line.chomp)
- }
- yield
- f.rewind
- each { |line|
- if line
- f.puts(line)
- else
- f.puts ""
- end
- }
- }
- end
-end
-
-array = Array.new
-array.tie("/tmp/textfile.txt", File::RDWR|File::CREAT) {
- array[4] = "a new line 4"
-}
-
-# The tied array can be manipulated like a normal array,
-# so there is no need for a special API, and the recno_demo program
-# to demonstrate is API is useless
-
-
-# tied array demo: show how to use array with a tied file
-filename = "db_file.txt"
-lines = Array.new
-File.unlink(filename) if File.exists?(filename)
-lines.tie(filename, File::RDWR | File::CREAT) {
- # first create a textfile to play with
- lines[0] = "zero"
- lines[1] = "one"
- lines[2] = "two"
- lines[3] = "three"
- lines[4] = "four"
-
- # print the records in order.
- # Opposed to perl, the tied array behaves exactly as a normal array
- puts "\nOriginal"
- for i in 0..(lines.length-1)
- puts "#{i}: #{lines[i]}"
- end
-
- #use push and pop
- a = lines.pop
- lines.push("last")
- puts("The last line was [#{a}]")
-
- #use shift and unshift
- a = lines.shift
- lines.unshift("first")
- puts("The first line was [#{a}]")
-
- # add record after record 2
- i = 2
- lines.insert(i + 1, "Newbie")
-
- # add record before record one
- i = 1
- lines.insert(i, "New One")
-
- # delete record 3
- lines.delete_at(3)
-
- #now print the records in reverse order
- puts "\nReverse"
- (lines.length - 1).downto(0){ |i|
- puts "#{i}: #{lines[i]}"
- }
-
-}
-
-
-# @@PLEAC@@_14.8
-# example to store complex data in a database
-# uses marshall from the standard library
-require "sdbm"
-db = SDBM.open("pleac14-8-database", 0666)
-
-# convert the Objects into strings and back by using the Marshal module.
-# Most normal objects can be converted out of the box,
-# but not special things like procedure objects,
-# IO instance variables, singleton objects
-
-db["Tom Christiansen"] = Marshal.dump(["book author", "tchrist@perl.com"])
-db["Tom Boutell"] = Marshal.dump(["shareware author",
-"boutell@boutell.com"])
-
-name1 = "Tom Christiansen"
-name2 = "Tom Boutell"
-
-tom1 = Marshal.load(db[name1])
-tom2 = Marshal.load(db[name2])
-
-puts "Two Toming: #{tom1} #{tom2}"
-
-if tom1[0] == tom2[0] && tom1[1] == tom2[1]
- puts "You're having runtime fun with one Tom made two."
-else
- puts "No two Toms are ever alike"
-end
-
-# To change parts of an entry, get the whole entry, change the parts,
-# and save the whole entry back
-entry = Marshal.load(db["Tom Boutell"])
-entry[0] = "Poet Programmer"
-db["Tom Boutell"] = Marshal.dump(entry)
-db.close
-
-
-# @@PLEAC@@_14.9
-# example to make data persistent
-# uses Marshal from the standard lib
-# Stores the data in a simple file,
-# see 14.8 on how to store it in a dbm file
-
-# The BEGIN block is executed before the rest of the script
-# we use global variables here because local variables
-# will go out of scope and are not accessible from the main script
-
-BEGIN {
- $persistent_store = "persitence.dat"
- begin
- File.open($persistent_store) do |f|
- $stringvariable1 = Marshal.load(f)
- $arrayvariable2 = Marshal.load(f)
- end
- rescue
- puts "Can not open #{$persistent_store}"
- # Initialisation if this script runs the first time
- $stringvariable1 = ""
- $arrayvariable2 = []
- end
-}
-
-END {
- File.open($persistent_store, "w+") do |f|
- Marshal.dump($stringvariable1, f)
- Marshal.dump($arrayvariable2, f)
- end
-}
-
-# simple test program
-puts $stringvariable1
-puts $arrayvariable2
-$stringvariable1 = "Hello World"
-$arrayvariable2.push(5)
-puts $stringvariable1
-puts $arrayvariable2
-
-
-# @@PLEAC@@_14.10
-#!/usr/bin/ruby -w
-# Ruby has a dbi module with an architecture similar
-# to the Perl dbi module: the dbi module provides an unified
-# interface and uses specialized drivers for each dbms vendor
-#
-begin
- DBI.connect("DBI:driver:driverspecific", "username", "auth") {
- |dbh|
-
- dbh.do(SQL1)
-
- dbh.prepare(SQL2){ |sth|
- sth.execute
- sth.fetch {|row|
- # ...
- }
- } # end of block finishes the statement handle
- } # end of block closes the database connection
-rescue DBI::DatabaseError => e
- puts "dbi error occurred"
- puts "Error code: #{e.err}"
- puts "Error message: #{e.errstr}"
-end
-
-#!/usr/bin/ruby -w
-# dbusers - example for mysql which creates a table,
-# fills it with values, retrieves the values back,
-# and finally destroys the table.
-
-require "dbi"
-
-# replacement for the User::pwnt module
-def getpwent
- result = []
- File.open("/etc/passwd") {|file|
- file.each_line {|line|
- next if line.match(/^#/)
- cols = line.split(":")
- result.push([cols[2], cols[0]])
- }
- }
- result
-end
-
-begin
- DBI.connect("DBI:Mysql:pleacdatabase", "pleac", "pleacpassword") {
- |conn|
-
- conn.do("CREATE TABLE users (uid INT, login CHAR(8))")
-
- users = getpwent
-
- conn.prepare("INSERT INTO users VALUES (?,?)") {|sth|
- users.each {|entry|
- sth.execute(entry[0], entry[1])
- }
- }
-
- conn.execute("SELECT uid, login FROM users WHERE uid < 50") {|sth|
- sth.fetch {|row|
- puts row.collect {|col|
- if col.nil?
- "(null)"
- else
- col
- end
- }.join(", ")
- }
- }
-
- conn.do("DROP TABLE users")
- }
-rescue DBI::DatabaseError => e
- puts "dbi error occurred"
- puts "Error code: #{e.err}"
- puts "Error message: #{e.errstr}"
-end
-
-
-# @@PLEAC@@_15.1
-# This test program demonstrates parsing program arguments.
-# It uses the optparse library, which is included with ruby 1.8
-# It handles classic unix style and gnu style options
-require 'optparse'
-
-@debugmode = false
-@verbose = false
-
-ARGV.options do |opts|
- opts.banner = "Usage: ruby #{$0} [OPTIONS] INPUTFILES"
-
- opts.on("-h", "--help", "show this message") {
- puts opts
- exit
- }
- # The OptionParser#on method is called with a specification of short
- # options, of long options, a data type spezification and user help
- # messages for this option.
- # The method analyses the given parameter and decides what it is,
- # so you can leave out the long option if you don't need it
- opts.on("-v", "--[no-]verbose=[FLAG]", TrueClass, "run verbosly") {
- |@verbose| # sets @verbose to true or false
- }
- opts.on("-D", "--DEBUG", TrueClass, "turns on debug mode" ){
- |@debugmode| # sets @debugmode to true
- }
- opts.on("-c", "--count=NUMBER", Integer, "how many times we do it" ){
- |@count| # sets @count to given integer
- }
- opts.on("-o", "--output=FILE", String, "file to write output to"){
- |@outputfile| # sets @outputfile to given string
- }
- opts.parse!
-end
-
-# example to use the options in the main program
-puts "Verbose is on" if @verbose
-puts "Debugmode is on" if @debugmode
-puts "Outfile is #{@outputfile}" if defined? @outputfile
-puts "Count is #{@count}" if defined? @count
-ARGV.each { |param|
- puts "Got parameter #{param}"
-}
-
-
-# @@PLEAC@@_15.4
-buf = "\0" * 8
-$stdout.ioctl(0x5413, buf)
-ws_row, ws_col, ws_xpixel, ws_ypixel = buf.unpack("S4")
-
-raise "You must have at least 20 characters" unless ws_col >= 20
-max = 0
-values = (1..5).collect { rand(20) } # generate an array[5] of rand values
-for i in values
- max = i if max < i
-end
-ratio = Float(ws_col-12)/max # chars per unit
-for i in values
- printf "%8.1f %s\n", i, "*" * (ratio*i)
-end
-
-# gives, for example:
-# 15.0 *******************************
-# 10.0 *********************
-# 5.0 **********
-# 14.0 *****************************
-# 18.0 **************************************
-
-
-# @@PLEAC@@_16.1
-output = `program args` # collect output into one multiline string
-output = `program args`.split # collect output into array, one line per
-element
-
-readme = IO.popen("ls")
-output = ""
-while readme.gets do
- output += $_
-end
-readme.close
-
-`fsck -y /dev/rsd1a` # BAD AND SCARY in Perl because it's managed by the shell
- # I donna in Ruby ...
-
-# so the "clean and secure" version
-readme, writeme = IO.pipe
-pid = fork {
- # child
- $stdout = writeme
- readme.close
- exec('find', '..')
-}
-# parent
-Process.waitpid(pid, 0)
-writeme.close
-while readme.gets do
- # do something with $_
-end
-
-
-# @@PLEAC@@_16.2
-status = system("xemacs #{myfile}")
-
-status = system("xemacs", myfile)
-
-system("cmd1 args | cmd2 | cmd3 >outfile")
-system("cmd args <infile >outfile 2>errfile")
-
-# stop if the command fails
-raise "$program exited funny: #{$?}" unless system("cmd", "args1", "args2")
-
-# get the value of the signal sent to the child
-# even if it is a SIGINT or SIGQUIT
-system(arglist)
-raise "program killed by signal #{$?}" if ($? & 127) != 0
-
-pid = fork {
- trap("SIGINT", "IGNORE")
- exec("sleep", "10")
-}
-trap ("SIGINT") {
- puts "Tsk tsk, no process interruptus"
-}
-Process.waitpid(pid, 0)
-
-# Ruby doesn't permit to lie to the program called by a 'system'.
-# (ie specify what return argv[0] in C, $0 in Perl/Ruby ...)
-# A (dirty) way is to create a link (under Unix), run this link and
-# erase it. Somebody has a best idea ?
-
-
-# @@PLEAC@@_16.3
-exec("archive *.data")
-
-exec("archive", "accounting.data")
-
-exec("archive accounting.data")
-
-
-# @@PLEAC@@_16.4
-# read the output of a program
-IO.popen("ls") {|readme|
- while readme.gets do
- # ...
- end
-}
-# or
-readme = IO.popen("ls")
-while readme.gets do
- # ...
-end
-readme.close
-
-# "write" in a program
-IO.popen("cmd args","w") {|pipe|
- pipe.puts("data")
- pipe.puts("foo")
-}
-
-# close wait for the end of the process
-read = IO.popen("sleep 10000") # child goes to sleep
-read.close # and the parent goes to lala land
-
-writeme = IO.popen("cmd args", "w")
-writeme.puts "hello" # program will get hello\n on STDIN
-writeme.close # program will get EOF on STDIN
-
-# send in a pager (eg less) all output
-$stdout = IO.popen("/usr/bin/less","w")
-print "huge string\n" * 10000
-
-
-# @@PLEAC@@_16.5
-#-----------------------------
-def head(lines = 20)
- pid = open("|-","w")
- if pid == nil
- return
- else
- while gets() do
- pid.print
- lines -= 1
- break if lines == 0
- end
- end
- exit
-end
-
-head(100)
-while gets() do
- print
-end
-#-----------------------------
-1: > Welcome to Linux, version 2.0.33 on a i686
-
-2: >
-
-3: > "The software required `Windows 95 or better',
-
-4: > so I installed Linux."
-#-----------------------------
-> 1: Welcome to Linux, Kernel version 2.0.33 on a i686
-
-> 2:
-
-> 3: "The software required `Windows 95 or better',
-
-> 4: so I installed Linux."
-#-----------------------------
-#!/usr/bin/ruby
-# qnumcat - demo additive output filters
-
-def number()
- pid = open("|-","w")
- if pid == nil
- return
- else
- while gets() do pid.printf("%d: %s", $., $_); end
- end
- exit
-end
-
-def quote()
- pid = open("|-","w")
- if pid == nil
- return
- else
- while gets() do pid.print "> #{$_}" end
- end
- exit
-end
-
-number()
-quote()
-
-while gets() do
- print
-end
-$stdout.close
-exit
-
-
-# @@PLEAC@@_16.6
-ARGV.map! { |arg|
- arg =~ /\.(gz|Z)$/ ? "|gzip -dc #{arg}" : arg
-}
-for file in ARGV
- fh = open(file)
- while fh.gets() do
- # .......
- end
-end
-#-----------------------------
-ARGV.map! { |arg|
- arg =~ %r#^\w+://# ? "|GET #{arg}" : arg #
-}
-for file in ARGV
- fh = open(file)
- while fh.gets() do
- # .......
- end
-end
-#-----------------------------
-pwdinfo = (`domainname` =~ /^(\(none\))?$/) ? '/etc/passwd' : '|ypcat passwd';
-pwd = open(pwdinfo);
-#-----------------------------
-puts "File, please? ";
-file = gets().chomp();
-fh = open(file);
-
-
-# @@PLEAC@@_16.7
-output = `cmd 2>&1` # with backticks
-# or
-ph = open("|cmd 2>&1") # with an open pipe
-while ph.gets() { } # plus a read
-#-----------------------------
-output = `cmd 2>/dev/null` # with backticks
-# or
-ph = open("|cmd 2>/dev/null") # with an open pipe
-while ph.gets() { } # plus a read
-#-----------------------------
-output = `cmd 2>&1 1>/dev/null` # with backticks
-# or
-ph = open("|cmd 2>&1 1>/dev/null") # with an open pipe
-while ph.gets() { } # plus a read
-#-----------------------------
-output = `cmd 3>&1 1>&2 2>&3 3>&-` # with backticks
-# or
-ph = open("|cmd 3>&1 1>&2 2>&3 3>&-") # with an open pipe
-while ph.gets() { } # plus a read
-#-----------------------------
-system("program args 1>/tmp/program.stdout 2>/tmp/program.stderr")
-#-----------------------------
-output = `cmd 3>&1 1>&2 2>&3 3>&-`
-#-----------------------------
-fd3 = fd1
-fd1 = fd2
-fd2 = fd3
-fd3 = undef
-#-----------------------------
-system("prog args 1>tmpfile 2>&1")
-system("prog args 2>&1 1>tmpfile")
-#-----------------------------
-# system ("prog args 1>tmpfile 2>&1")
-fd1 = "tmpfile" # change stdout destination first
-fd2 = fd1 # now point stderr there, too
-#-----------------------------
-# system("prog args 2>&1 1>tmpfile")
-fd2 = fd1 # stderr same destination as stdout
-fd1 = "tmpfile" # but change stdout destination
-#-----------------------------
-# It is often better not to rely on the shell,
-# because of portability, possible security problems
-# and bigger resource usage. So, it is often better to use the open3 library.
-# See below for an example.
-# opening stdin, stdout, stderr
-require "open3"
-stdin, stdout, stderr = Open3.popen('cmd')
-
-
-# @@PLEAC@@_16.8
-#-----------------------------
-# Contrary to perl, we don't need to use a module in Ruby
-fh = Kernel.open("|" + program, "w+")
-fh.puts "here's your input\n"
-output = fh.gets()
-fh.close()
-#-----------------------------
-Kernel.open("|program"),"w+") # RIGHT !
-#-----------------------------
-# Ruby has already object methods for I/O handles
-#-----------------------------
-begin
- fh = Kernel.open("|" + program_and_options, "w+")
-rescue
- if ($@ ~= /^open/)
- $stderr.puts "open failed : #{$!} \n #{$@} \n"
- break
- end
- raise # reraise unforseen exception
-end
-
-
-# @@PLEAC@@_16.13
-#% kill -l
-#HUP INT QUIT ILL TRAP ABRT BUS FPE KILL USR1 SEGV USR2 PIPE
-#ALRM TERM CHLD CONT STOP TSTP TTIN TTOU URG XCPU XFSZ VTALRM
-#PROF WINCH POLL PWR
-#-----------------------------
-#% ruby -e 'puts Signal.list.keys.join(" ")'
-#PWR USR1 BUS USR2 TERM SEGV KILL POLL STOP SYS TRAP IOT HUP INT #
-#WINCH XCPU TTIN CLD TSTP FPE IO TTOU PROF CHLD CONT PIPE ABRT
-#VTALRM QUIT ILL XFSZ URG ALRM
-#-----------------------------
-# After that, the perl script create an hash equivalent to Signal.list,
-# and an array. The array can be obtained by :
-signame = []
-Signal.list.each { |name, i| signame[i] = name }
-
-
-# @@PLEAC@@_16.14
-Process.kill(9, pid) # send $pid a signal 9
-Process.kill(-1, Process.getpgrp()) # send whole job a signal 1
-Process.kill("USR1", $$) # send myself a SIGUSR1
-Process.kill("HUP", pid1, pid2, pid3) # send a SIGHUP to processes in @pids
-#-----------------------------
-begin
- Process.kill(0, minion)
- puts "#{minion} is alive!"
-rescue Errno::EPERM # changed uid
- puts "#{minion} has escaped my control!";
-rescue Errno::ESRCH
- puts "#{minion} is deceased."; # or zombied
-rescue
- puts "Odd; I couldn't check the status of #{minion} : #{$!}"
-end
-
-
-# @@PLEAC@@_16.15
-Kernel.trap("QUIT", got_sig_quit) # got_sig_quit = Proc.new { puts "Quit\n" }
-trap("PIPE", "got_sig_quit") # def got_sig_pipe ...
-trap("INT") { ouch++ } # increment ouch for every SIGINT
-#-----------------------------
-trap("INT", "IGNORE") # ignore the signal INT
-#-----------------------------
-trap("STOP", "DEFAULT") # restore default STOP signal handling
-
-
-# @@PLEAC@@_16.16
-# the signal handler
-def ding
- trap("INT", "ding")
- puts "\aEnter your name!"
-end
-
-# prompt for name, overriding SIGINT
-def get_name
- save = trap("INT", "ding")
-
- puts "Kindly Stranger, please enter your name: "
- name = gets().chomp()
- trap("INT", save)
- name
-end
-
-
-# @@PLEAC@@_16.21
-# implemented thanks to http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/1760
-require 'timeout'
-
-# we'll do something vastly more useful than cookbook to demonstrate timeouts
-begin
- timeout(5) {
- waitsec = rand(10)
- puts "Let's see if a sleep of #{waitsec} seconds is longer than 5 seconds..."
- system("sleep #{waitsec}")
- }
- puts "Timeout didn't occur"
-rescue Timeout::Error
- puts "Timed out!"
-end
-
-
-# @@PLEAC@@_17.1
-# A basic TCP client connection
-require 'socket'
-begin
- t = TCPSocket.new('www.ruby-lang.org', 'www')
-rescue
- puts "error: #{$!}"
-else
- # ... do something with the socket
- t.print "GET / HTTP/1.0\n\n"
- answer = t.gets(nil)
- # and terminate the connection when we're done
- t.close
-end
-
-# Using the evil low level socket API
-require 'socket'
-# create a socket
-s = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM, 0)
-# build the address of the remote machine
-sockaddr_server = [Socket::AF_INET, 80,
- Socket.gethostbyname('www.ruby-lang.org')[3],
- 0, 0].pack("snA4NN")
-# connect
-begin
- s.connect(sockaddr_server)
-rescue
- puts "error: #{$!}"
-else
- # ... do something with the socket
- s.print "GET / HTTP/1.0\n\n"
- # and terminate the connection when we're done
- s.close
-end
-
-# TCP connection with management of error (DNS)
-require 'socket'
-begin
- client = TCPSocket.new('does not exists', 'www')
-rescue
- puts "error: #{$!}"
-end
-
-# TCP connection with a time out
-require 'socket'
-require 'timeout'
-begin
- timeout(1) do #the server has one second to answer
- client = TCPSocket.new('www.host.com', 'www')
- end
-rescue
- puts "error: #{$!}"
-end
-
-
-# @@PLEAC@@_17.12
-require 'socket'
-
-class Preforker
- attr_reader (:child_count)
-
- def initialize(prefork, max_clients_per_child, port, client_handler)
- @prefork = prefork
- @max_clients_per_child = max_clients_per_child
- @port = port
- @child_count = 0
-
- @reaper = proc {
- trap('CHLD', @reaper)
- pid = Process.wait
- @child_count -= 1
- }
-
- @huntsman = proc {
- trap('CHLD', 'IGNORE')
- trap('INT', 'IGNORE')
- Process.kill('INT', 0)
- exit
- }
-
- @client_handler=client_handler
- end
-
- def child_handler
- trap('INT', 'EXIT')
- @client_handler.setUp
- # wish: sigprocmask UNblock SIGINT
- @max_clients_per_child.times {
- client = @server.accept or break
- @client_handler.handle_request(client)
- client.close
- }
- @client_handler.tearDown
- end
-
- def make_new_child
- # wish: sigprocmask block SIGINT
- @child_count += 1
- pid = fork do
- child_handler
- end
- # wish: sigprocmask UNblock SIGINT
- end
-
- def run
- @server = TCPserver.open(@port)
- trap('CHLD', @reaper)
- trap('INT', @huntsman)
- loop {
- (@prefork - @child_count).times { |i|
- make_new_child
- }
- sleep .1
- }
- end
-end
-
-#-----------------------------
-#!/usr/bin/ruby
-
-require 'Preforker'
-
-class ClientHandler
- def setUp
- end
-
- def tearDown
- end
-
- def handle_request(client)
- # do stuff
- end
-end
-
-server = Preforker.new(1, 100, 3102, ClientHandler.new)
-server.run
-
-
-# @@PLEAC@@_18.2
-require 'net/ftp'
-
-begin
- ftp = Net::FTP::new("ftp.host.com")
- ftp.login(username,password)
- ftp.chdir(directory)
- ftp.get(filename)
- ftp.put(filename)
-rescue Net::FTPError
- $stderr.print "FTP failed: " + $!
-ensure
- ftp.close() if ftp
-end
-
-# A better solution for a local use could be :
-Net::FTP::new("ftp.host.com") do |ftp|
- ftp.login(username,password)
- ftp.chdir(directory)
- ftp.get(filename)
- ftp.put(filename)
-end
-
-# If you have only one file to get, there is a simple solution :
-require 'open-uri'
-open("ftp://www.ruby-lang.org/path/filename") do |fh|
- # read from filehandle fh
-end
-#--------------------------------------------
-# to wait a defined time for the connection,
-# use the timeout module
-require 'timeout'
-begin
- timeout(30){
- ftp = Net::FTP::new("ftp.host.com")
- ftp.debug_mode = true
- }
-rescue Net::FTPError
- $stderr.puts "Couldn't connect."
-rescue Timeout::Error
- $stderr.puts "Timeout while connecting to server."
-end
-
-begin
- ftp.login()
-rescue Net::FTPError
- $stderr.print "Couldn't authentificate.\n"
-end
-
-begin
- ftp.login(username)
-rescue Net::FTPError
- $stderr.print "Still couldn't authenticate.\n"
-end
-
-begin
- ftp.login(username, password)
-rescue Net::FTPError
- $stderr.print "Couldn't authenticate, even with explicit
- username and password.\n"
-end
-
-begin
- ftp.login(username, password, account)
-rescue Net::FTPError
- $stderr.print "No dice. It hates me.\n"
-end
-#-----------------------------
-ftp.put(localfile, remotefile)
-#-----------------------------
-# Sending data from STDIN is not directly supported
-# by the ftp library module. A possible way to do it is to use the
-# storlines method directly to send raw commands to the ftp server.
-#-----------------------------
-ftp.get(remotefile, localfile)
-#-----------------------------
-ftp.get(remotefile) { |data| puts data }
-#-----------------------------
-ftp.chdir("/pub/ruby")
-print "I'm in the directory ", ftp.pwd(), "\n"
-#-----------------------------
-ftp.mkdir("/pub/ruby/new_dir")
-#-----------------------------
-lines = ftp.ls("/pub/ruby/")
-# => ["drwxr-xr-x 2 matz users 4096 July 17 1998 1.0", ... ]
-
-latest = ftp.dir("/pub/ruby/*.tgz").sort.last
-
-ftp.nlst("/pub/ruby")
-# => ["/pub/ruby/1.0", ... ]
-#-----------------------------
-ftp.quit()
-
-
-# @@PLEAC@@_18.6
-require 'net/telnet'
-t = Net::Telnet::new( "Timeout" => 10,
- "Prompt" => /%/,
- "Host" => host )
-t.login(username, password)
-files = t.cmd("ls")
-t.print("top")
-process_string = t.waitfor(/\d+ processes/)
-t.close
-#-----------------------------
-/[$%#>] \z/n
-#-----------------------------
-# In case of an error, the telnet module throws an exception.
-# For control of the behavior in case of an error,
-# you just need to catch the exceptions and do your custom
-# error handling.
-#-----------------------------
-begin
- telnet.login(username, password)
-rescue TimeoutError
- fail "Login failed !\n"
-end
-#-----------------------------
-telnet.waitfor('/--more--/')
-#-----------------------------
-telnet.waitfor(String => 'greasy smoke', Timeout => 30)
-
-
-# @@PLEAC@@_18.7
-require 'ping'
-
-puts "#{host} is alive.\n" if Ping.pingecho(host);
-#-----------------------------
-# the ping module only use TCP ping, not ICMP even if we are root
-if Ping.pingecho("kingkong.com")
- puts "The giant ape lives!\n";
-else
- puts "All hail mighty Gamera, friend of children!\n";
-end
-
-
-# @@PLEAC@@_19.1
-#!/usr/local/bin/ruby -w
-# hiweb - load CGI class to decode information given by web server
-
-require 'cgi'
-
-cgi = CGI.new('html3')
-
-# get a parameter from a form
-value = cgi.params['PARAM_NAME'][0]
-
-# output a document
-cgi.out {
- cgi.html {
- cgi.head { cgi.title { "Howdy there!" } } +
- cgi.body { cgi.p { "You typed: " + cgi.tt {
- CGI.escapeHTML(value) } } }
- }
-}
-
-require 'cgi'
-cgi = CGI.new
-who = cgi.param["Name"][0] # first param in list
-phone = cgi.param["Number"][0]
-picks = cgi.param["Choices"] # complete list
-
-print cgi.header( 'type' => 'text/plain',
- 'expires' => Time.now + (3 * 24 * 60 * 60) )
-
-
-# @@PLEAC@@_19.3
-#!/usr/local/bin/ruby -w
-# webwhoami - show web user's id
-require 'etc'
-print "Content-Type: text/plain\n\n"
-print "Running as " + Etc.getpwuid.name + "\n"
-
-# % ruby -wc cgi-script # just check syntax
-
-# % ruby -w cgi-script # params from stdin
-# (offline mode: enter name=value pairs on standard input)
-# name=joe
-# number=10
-# ^D
-
-# % ruby -w cgi-script name=joe number=10 # run with mock form input
-# % ruby -d cgi-script name=joe number=10 # ditto, under the debugger
-
-# POST method script in csh
-# % (setenv HTTP_METHOD POST; ruby -w cgi-script name=joe number=10)
-# POST method script in sh
-# % HTTP_METHOD=POST perl -w cgi-script name=joe number=10
-
-
-# @@PLEAC@@_19.4
-# ruby has several security levels, the level "1" is similar to perls taint mode.
-# It can be switched on by providing the -T command line parameter
-# or by setting $SAFE to 1. Setting $SAFE to 2,3 or 4 restricts possible
-# harmful operations further.
-
-#!/usr/bin/ruby -T
-$SAFE = 1
-File.open(ARGV[0], "w")
-# ruby warns with:
-# taint1.rb:2:in `initialize': Insecure operation - initialize (SecurityError)
-
-$SAFE = 1
-file = ARGV[0]
-unless /^([\w.-]+)$/.match(file)
- raise "filename #{file} has invalid characters"
-end
-file = $1
-# In ruby, even the back reference from a regular expression stays tainted.
-# you need to explicitly untaint the variable:
-file.untaint
-File.open(file, "w")
-
-# Race condition exists like in perl:
-unless File.exists(filename) # Wrong because of race condition
- File.open(filename, "w")
-end
-
-
-
-# @@PLEAC@@_19.10
-preference_value = cgi.cookies["preference name"][0]
-
-packed_cookie = CGI::Cookie.new("name" => "preference name",
- "value" => "whatever you'd like",
- "expires" => Time.local(Time.now.year + 2,
- Time.now.mon, Time.now.day, Time.now.hour, Time.now.min, Time.now.sec) )
-
-cgi.header("cookie" => [packed_cookie])
-
-#!/usr/local/bin/ruby -w
-# ic_cookies - sample CGI script that uses a cookie
-require 'cgi'
-
-cgi = CGI.new('html3')
-
-cookname = "favorite ice cream"
-favorite = cgi.params["flavor"][0]
-tasty = cgi.cookies[cookname][0] || 'mint'
-
-unless favorite
- cgi.out {
- cgi.html {
- cgi.head { cgi.title { "Ice Cookies" } } +
- cgi.body {
- cgi.h1 { "Hello Ice Cream" } +
- cgi.hr +
- cgi.form {
- cgi.p { "Please select a flavor: " +
- cgi.text_field("flavor", tasty ) }
- } +
- cgi.hr
- }
- }
- }
-else
- cookie = CGI::Cookie.new( "name" => cookname,
- "value" => favorite,
- "expires" => Time.local(Time.now.year + 2,
-Time.now.mon, Time.now.day, Time.now.hour, Time.now.min, Time.now.sec) )
- cgi.out("cookie" => [cookie]) {
- cgi.html {
- cgi.head { cgi.title { "Ice Cookies" } } +
- cgi.body {
- cgi.h1 { "Hello Ice Cream" } +
- cgi.p { "You chose as your favorite flavor `#{favorite}'." }
- }
- }
- }
-end
-
-
-# @@PLEAC@@_20.9
-def templatefile(filename, fillings)
- aFile = File.new(filename, "r")
- text = aFile.read()
- aFile.close()
- pattern = Regexp.new('%%(.*?)%%')
- text.gsub!(pattern) {
- fillings[$1] || ""
- }
- text
-end
-
-fields = {
- 'username' => whats_his_name,
- 'count' => login_count,
- 'total' => minutes_used
-}
-puts templatefile('simple.template', fields)
-
-# @@INCOMPLETE@@
-# An example using databases is missing
|