Merge pull request #482 from python-cmd2/run_at_invocation

Add example and documentation for #452

1 files changed, 114 insertions, 0 deletions

diff --git a/examples/cmd_as_argument.py b/examples/cmd_as_argument.py
new file mode 100755
index 00000000..eb46eedf
--- /dev/null
+++ b/examples/cmd_as_argument.py
@@ -0,0 +1,114 @@
+#!/usr/bin/env python
+# coding=utf-8
+"""
+A sample application for cmd2.
+
+This example is very similar to example.py, but had additional
+code in main() that shows how to accept a command from
+the command line at invocation:
+
+$ python cmd_as_argument.py speak -p hello there
+
+
+"""
+
+import argparse
+import random
+import sys
+
+import cmd2
+
+
+class CmdLineApp(cmd2.Cmd):
+    """ Example cmd2 application. """
+
+    # Setting this true makes it run a shell command if a cmd2/cmd command doesn't exist
+    # default_to_shell = True
+    MUMBLES = ['like', '...', 'um', 'er', 'hmmm', 'ahh']
+    MUMBLE_FIRST = ['so', 'like', 'well']
+    MUMBLE_LAST = ['right?']
+
+    def __init__(self):
+        self.allow_cli_args = False
+        self.multiline_commands = ['orate']
+        self.maxrepeats = 3
+
+        # Add stuff to settable and shortcuts before calling base class initializer
+        self.settable['maxrepeats'] = 'max repetitions for speak command'
+        self.shortcuts.update({'&': 'speak'})
+
+        # Set use_ipython to True to enable the "ipy" command which embeds and interactive IPython shell
+        super().__init__(use_ipython=False)
+
+    speak_parser = argparse.ArgumentParser()
+    speak_parser.add_argument('-p', '--piglatin', action='store_true', help='atinLay')
+    speak_parser.add_argument('-s', '--shout', action='store_true', help='N00B EMULATION MODE')
+    speak_parser.add_argument('-r', '--repeat', type=int, help='output [n] times')
+    speak_parser.add_argument('words', nargs='+', help='words to say')
+
+    @cmd2.with_argparser(speak_parser)
+    def do_speak(self, args):
+        """Repeats what you tell me to."""
+        words = []
+        for word in args.words:
+            if args.piglatin:
+                word = '%s%say' % (word[1:], word[0])
+            if args.shout:
+                word = word.upper()
+            words.append(word)
+        repetitions = args.repeat or 1
+        for i in range(min(repetitions, self.maxrepeats)):
+            # .poutput handles newlines, and accommodates output redirection too
+            self.poutput(' '.join(words))
+
+    do_say = do_speak  # now "say" is a synonym for "speak"
+    do_orate = do_speak  # another synonym, but this one takes multi-line input
+
+    mumble_parser = argparse.ArgumentParser()
+    mumble_parser.add_argument('-r', '--repeat', type=int, help='how many times to repeat')
+    mumble_parser.add_argument('words', nargs='+', help='words to say')
+
+    @cmd2.with_argparser(mumble_parser)
+    def do_mumble(self, args):
+        """Mumbles what you tell me to."""
+        repetitions = args.repeat or 1
+        for i in range(min(repetitions, self.maxrepeats)):
+            output = []
+            if random.random() < .33:
+                output.append(random.choice(self.MUMBLE_FIRST))
+            for word in args.words:
+                if random.random() < .40:
+                    output.append(random.choice(self.MUMBLES))
+                output.append(word)
+            if random.random() < .25:
+                output.append(random.choice(self.MUMBLE_LAST))
+            self.poutput(' '.join(output))
+
+
+def main(argv=None):
+    """Run when invoked from the operating system shell"""
+
+    parser = argparse.ArgumentParser(
+        description='Commands as arguments'
+    )
+    command_help = 'optional command to run, if no command given, enter an interactive shell'
+    parser.add_argument('command', nargs='?',
+                        help=command_help)
+    arg_help = 'optional arguments for command'
+    parser.add_argument('command_args', nargs=argparse.REMAINDER,
+                        help=arg_help)
+
+    args = parser.parse_args(argv)
+
+    c = CmdLineApp()
+
+    if args.command:
+        # we have a command, run it and then exit
+        c.onecmd_plus_hooks('{} {}'.format(args.command, ' '.join(args.command_args)))
+    else:
+        # we have no command, drop into interactive mode
+        c.cmdloop()
+
+
+if __name__ == '__main__':
+    sys.exit(main())
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