gzip-1.8HEADgzip-1.8master

1 files changed, 2157 insertions, 0 deletions

diff --git a/gzip.c b/gzip.c
new file mode 100644
index 0000000..4a51b13
--- /dev/null
+++ b/gzip.c
@@ -0,0 +1,2157 @@
+/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
+
+   Copyright (C) 1999, 2001-2002, 2006-2007, 2009-2016 Free Software
+   Foundation, Inc.
+   Copyright (C) 1992-1993 Jean-loup Gailly
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/*
+ * The unzip code was written and put in the public domain by Mark Adler.
+ * Portions of the lzw code are derived from the public domain 'compress'
+ * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
+ * Ken Turkowski, Dave Mack and Peter Jannesen.
+ *
+ * See the license_msg below and the file COPYING for the software license.
+ * See the file algorithm.doc for the compression algorithms and file formats.
+ */
+
+static char const *const license_msg[] = {
+"Copyright (C) 2016 Free Software Foundation, Inc.",
+"Copyright (C) 1993 Jean-loup Gailly.",
+"This is free software.  You may redistribute copies of it under the terms of",
+"the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.",
+"There is NO WARRANTY, to the extent permitted by law.",
+0};
+
+/* Compress files with zip algorithm and 'compress' interface.
+ * See help() function below for all options.
+ * Outputs:
+ *        file.gz:   compressed file with same mode, owner, and utimes
+ *     or stdout with -c option or if stdin used as input.
+ * If the output file name had to be truncated, the original name is kept
+ * in the compressed file.
+ * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
+ *
+ * Using gz on MSDOS would create too many file name conflicts. For
+ * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
+ * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
+ * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
+ * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
+ *
+ * For the meaning of all compilation flags, see comments in Makefile.in.
+ */
+
+#include <config.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+#include "tailor.h"
+#include "gzip.h"
+#include "intprops.h"
+#include "lzw.h"
+#include "revision.h"
+#include "timespec.h"
+
+#include "dirname.h"
+#include "fcntl--.h"
+#include "getopt.h"
+#include "ignore-value.h"
+#include "stat-time.h"
+#include "version.h"
+#include "yesno.h"
+
+                /* configuration */
+
+#include <limits.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#ifndef NO_DIR
+# define NO_DIR 0
+#endif
+#if !NO_DIR
+# include <dirent.h>
+# include <savedir.h>
+#endif
+
+#ifndef NO_UTIME
+#  include <utimens.h>
+#endif
+
+#ifndef MAX_PATH_LEN
+#  define MAX_PATH_LEN   1024 /* max pathname length */
+#endif
+
+#ifndef SEEK_END
+#  define SEEK_END 2
+#endif
+
+#ifndef CHAR_BIT
+#  define CHAR_BIT 8
+#endif
+
+#ifdef off_t
+  off_t lseek (int fd, off_t offset, int whence);
+#endif
+
+#ifndef OFF_T_MAX
+# define OFF_T_MAX TYPE_MAXIMUM (off_t)
+#endif
+
+/* Use SA_NOCLDSTOP as a proxy for whether the sigaction machinery is
+   present.  */
+#ifndef SA_NOCLDSTOP
+# define SA_NOCLDSTOP 0
+# define sigprocmask(how, set, oset) /* empty */
+# define sigset_t int
+# if ! HAVE_SIGINTERRUPT
+#  define siginterrupt(sig, flag) /* empty */
+# endif
+#endif
+
+#ifndef HAVE_WORKING_O_NOFOLLOW
+# define HAVE_WORKING_O_NOFOLLOW 0
+#endif
+
+/* Separator for file name parts (see shorten_name()) */
+#ifdef NO_MULTIPLE_DOTS
+#  define PART_SEP "-"
+#else
+#  define PART_SEP "."
+#endif
+
+                /* global buffers */
+
+DECLARE(uch, inbuf,  INBUFSIZ +INBUF_EXTRA);
+DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
+DECLARE(ush, d_buf,  DIST_BUFSIZE);
+DECLARE(uch, window, 2L*WSIZE);
+#ifndef MAXSEG_64K
+    DECLARE(ush, tab_prefix, 1L<<BITS);
+#else
+    DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
+    DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
+#endif
+
+                /* local variables */
+
+/* If true, pretend that standard input is a tty.  This option
+   is deliberately not documented, and only for testing.  */
+static bool presume_input_tty;
+
+/* If true, transfer output data to the output file's storage device
+   when supported.  Otherwise, if the system crashes around the time
+   gzip is run, the user might lose both input and output data.  See:
+   Pillai TS et al.  All file systems are not created equal: on the
+   complexity of crafting crash-consistent applications. OSDI'14. 2014:433-48.
+   https://www.usenix.org/conference/osdi14/technical-sessions/presentation/pillai */
+static bool synchronous;
+
+static int ascii = 0;        /* convert end-of-lines to local OS conventions */
+       int to_stdout = 0;    /* output to stdout (-c) */
+static int decompress = 0;   /* decompress (-d) */
+static int force = 0;        /* don't ask questions, compress links (-f) */
+static int keep = 0;         /* keep (don't delete) input files */
+static int no_name = -1;     /* don't save or restore the original file name */
+static int no_time = -1;     /* don't save or restore the original file time */
+static int recursive = 0;    /* recurse through directories (-r) */
+static int list = 0;         /* list the file contents (-l) */
+       int verbose = 0;      /* be verbose (-v) */
+       int quiet = 0;        /* be very quiet (-q) */
+static int do_lzw = 0;       /* generate output compatible with old compress (-Z) */
+       int test = 0;         /* test .gz file integrity */
+static int foreground = 0;   /* set if program run in foreground */
+       char *program_name;   /* program name */
+       int maxbits = BITS;   /* max bits per code for LZW */
+       int method = DEFLATED;/* compression method */
+       int level = 6;        /* compression level */
+       int exit_code = OK;   /* program exit code */
+       int save_orig_name;   /* set if original name must be saved */
+static int last_member;      /* set for .zip and .Z files */
+static int part_nb;          /* number of parts in .gz file */
+       struct timespec time_stamp; /* original time stamp (modification time) */
+       off_t ifile_size;      /* input file size, -1 for devices (debug only) */
+static char *env;            /* contents of GZIP env variable */
+static char const *z_suffix; /* default suffix (can be set with --suffix) */
+static size_t z_len;         /* strlen(z_suffix) */
+
+/* The set of signals that are caught.  */
+static sigset_t caught_signals;
+
+/* If nonzero then exit with status WARNING, rather than with the usual
+   signal status, on receipt of a signal with this value.  This
+   suppresses a "Broken Pipe" message with some shells.  */
+static int volatile exiting_signal;
+
+/* If nonnegative, close this file descriptor and unlink ofname on error.  */
+static int volatile remove_ofname_fd = -1;
+
+static bool stdin_was_read;
+
+off_t bytes_in;             /* number of input bytes */
+off_t bytes_out;            /* number of output bytes */
+static off_t total_in;      /* input bytes for all files */
+static off_t total_out;	    /* output bytes for all files */
+char ifname[MAX_PATH_LEN]; /* input file name */
+char ofname[MAX_PATH_LEN]; /* output file name */
+static char dfname[MAX_PATH_LEN]; /* name of dir containing output file */
+static struct stat istat;         /* status for input file */
+int  ifd;                  /* input file descriptor */
+int  ofd;                  /* output file descriptor */
+static int dfd = -1;       /* output directory file descriptor */
+unsigned insize;           /* valid bytes in inbuf */
+unsigned inptr;            /* index of next byte to be processed in inbuf */
+unsigned outcnt;           /* bytes in output buffer */
+int rsync = 0;             /* make ryncable chunks */
+
+static int handled_sig[] =
+  {
+    /* SIGINT must be first, as 'foreground' depends on it.  */
+    SIGINT
+
+#ifdef SIGHUP
+    , SIGHUP
+#endif
+#if SIGPIPE
+    , SIGPIPE
+#endif
+#ifdef SIGTERM
+    , SIGTERM
+#endif
+#ifdef SIGXCPU
+    , SIGXCPU
+#endif
+#ifdef SIGXFSZ
+    , SIGXFSZ
+#endif
+  };
+
+/* For long options that have no equivalent short option, use a
+   non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
+enum
+{
+  PRESUME_INPUT_TTY_OPTION = CHAR_MAX + 1,
+  RSYNCABLE_OPTION,
+  SYNCHRONOUS_OPTION,
+
+  /* A value greater than all valid long options, used as a flag to
+     distinguish options derived from the GZIP environment variable.  */
+  ENV_OPTION
+};
+
+static char const shortopts[] = "ab:cdfhH?klLmMnNqrS:tvVZ123456789";
+
+static const struct option longopts[] =
+{
+ /* { name  has_arg  *flag  val } */
+    {"ascii",      0, 0, 'a'}, /* ascii text mode */
+    {"to-stdout",  0, 0, 'c'}, /* write output on standard output */
+    {"stdout",     0, 0, 'c'}, /* write output on standard output */
+    {"decompress", 0, 0, 'd'}, /* decompress */
+    {"uncompress", 0, 0, 'd'}, /* decompress */
+ /* {"encrypt",    0, 0, 'e'},    encrypt */
+    {"force",      0, 0, 'f'}, /* force overwrite of output file */
+    {"help",       0, 0, 'h'}, /* give help */
+ /* {"pkzip",      0, 0, 'k'},    force output in pkzip format */
+    {"keep",       0, 0, 'k'}, /* keep (don't delete) input files */
+    {"list",       0, 0, 'l'}, /* list .gz file contents */
+    {"license",    0, 0, 'L'}, /* display software license */
+    {"no-name",    0, 0, 'n'}, /* don't save or restore original name & time */
+    {"name",       0, 0, 'N'}, /* save or restore original name & time */
+    {"-presume-input-tty", no_argument, NULL, PRESUME_INPUT_TTY_OPTION},
+    {"quiet",      0, 0, 'q'}, /* quiet mode */
+    {"silent",     0, 0, 'q'}, /* quiet mode */
+    {"synchronous",0, 0, SYNCHRONOUS_OPTION},
+    {"recursive",  0, 0, 'r'}, /* recurse through directories */
+    {"suffix",     1, 0, 'S'}, /* use given suffix instead of .gz */
+    {"test",       0, 0, 't'}, /* test compressed file integrity */
+    {"no-time",    0, 0, 'T'}, /* don't save or restore the time stamp */
+    {"verbose",    0, 0, 'v'}, /* verbose mode */
+    {"version",    0, 0, 'V'}, /* display version number */
+    {"fast",       0, 0, '1'}, /* compress faster */
+    {"best",       0, 0, '9'}, /* compress better */
+    {"lzw",        0, 0, 'Z'}, /* make output compatible with old compress */
+    {"bits",       1, 0, 'b'}, /* max number of bits per code (implies -Z) */
+    {"rsyncable",  0, 0, RSYNCABLE_OPTION}, /* make rsync-friendly archive */
+    { 0, 0, 0, 0 }
+};
+
+/* local functions */
+
+local void try_help     (void) ATTRIBUTE_NORETURN;
+local void help         (void);
+local void license      (void);
+local void version      (void);
+local int input_eof	(void);
+local void treat_stdin  (void);
+local void treat_file   (char *iname);
+local int create_outfile (void);
+local char *get_suffix  (char *name);
+local int  open_input_file (char *iname, struct stat *sbuf);
+local void discard_input_bytes (size_t nbytes, unsigned int flags);
+local int  make_ofname  (void);
+local void shorten_name  (char *name);
+local int  get_method   (int in);
+local void do_list      (int ifd, int method);
+local int  check_ofname (void);
+local void copy_stat    (struct stat *ifstat);
+local void install_signal_handlers (void);
+local void remove_output_file (void);
+local RETSIGTYPE abort_gzip_signal (int);
+local void do_exit      (int exitcode) ATTRIBUTE_NORETURN;
+static void finish_out (void);
+      int main          (int argc, char **argv);
+static int (*work) (int infile, int outfile) = zip; /* function to call */
+
+#if ! NO_DIR
+local void treat_dir    (int fd, char *dir);
+#endif
+
+#define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
+
+static void
+try_help ()
+{
+  fprintf (stderr, "Try `%s --help' for more information.\n",
+           program_name);
+  do_exit (ERROR);
+}
+
+/* ======================================================================== */
+local void help()
+{
+    static char const* const help_msg[] = {
+ "Compress or uncompress FILEs (by default, compress FILES in-place).",
+ "",
+ "Mandatory arguments to long options are mandatory for short options too.",
+ "",
+#if O_BINARY
+ "  -a, --ascii       ascii text; convert end-of-line using local conventions",
+#endif
+ "  -c, --stdout      write on standard output, keep original files unchanged",
+ "  -d, --decompress  decompress",
+/*  -e, --encrypt     encrypt */
+ "  -f, --force       force overwrite of output file and compress links",
+ "  -h, --help        give this help",
+/*  -k, --pkzip       force output in pkzip format */
+ "  -k, --keep        keep (don't delete) input files",
+ "  -l, --list        list compressed file contents",
+ "  -L, --license     display software license",
+#ifdef UNDOCUMENTED
+ "  -m, --no-time     do not save or restore the original modification time",
+ "  -M, --time        save or restore the original modification time",
+#endif
+ "  -n, --no-name     do not save or restore the original name and time stamp",
+ "  -N, --name        save or restore the original name and time stamp",
+ "  -q, --quiet       suppress all warnings",
+#if ! NO_DIR
+ "  -r, --recursive   operate recursively on directories",
+#endif
+ "      --rsyncable   make rsync-friendly archive",
+ "  -S, --suffix=SUF  use suffix SUF on compressed files",
+ "      --synchronous synchronous output (safer if system crashes, but slower)",
+ "  -t, --test        test compressed file integrity",
+ "  -v, --verbose     verbose mode",
+ "  -V, --version     display version number",
+ "  -1, --fast        compress faster",
+ "  -9, --best        compress better",
+#ifdef LZW
+ "  -Z, --lzw         produce output compatible with old compress",
+ "  -b, --bits=BITS   max number of bits per code (implies -Z)",
+#endif
+ "",
+ "With no FILE, or when FILE is -, read standard input.",
+ "",
+ "Report bugs to <bug-gzip@gnu.org>.",
+  0};
+    char const *const *p = help_msg;
+
+    printf ("Usage: %s [OPTION]... [FILE]...\n", program_name);
+    while (*p) printf ("%s\n", *p++);
+}
+
+/* ======================================================================== */
+local void license()
+{
+    char const *const *p = license_msg;
+
+    printf ("%s %s\n", program_name, Version);
+    while (*p) printf ("%s\n", *p++);
+}
+
+/* ======================================================================== */
+local void version()
+{
+    license ();
+    printf ("\n");
+    printf ("Written by Jean-loup Gailly.\n");
+}
+
+local void progerror (char const *string)
+{
+    int e = errno;
+    fprintf (stderr, "%s: ", program_name);
+    errno = e;
+    perror(string);
+    exit_code = ERROR;
+}
+
+/* ======================================================================== */
+int main (int argc, char **argv)
+{
+    int file_count;     /* number of files to process */
+    size_t proglen;     /* length of program_name */
+    char **argv_copy;
+    int env_argc;
+    char **env_argv;
+
+    EXPAND(argc, argv); /* wild card expansion if necessary */
+
+    program_name = gzip_base_name (argv[0]);
+    proglen = strlen (program_name);
+
+    /* Suppress .exe for MSDOS, OS/2 and VMS: */
+    if (4 < proglen && strequ (program_name + proglen - 4, ".exe"))
+      program_name[proglen - 4] = '\0';
+
+    /* Add options in GZIP environment variable if there is one */
+    argv_copy = argv;
+    env = add_envopt (&env_argc, &argv_copy, OPTIONS_VAR);
+    env_argv = env ? argv_copy : NULL;
+
+#ifndef GNU_STANDARD
+# define GNU_STANDARD 1
+#endif
+#if !GNU_STANDARD
+    /* For compatibility with old compress, use program name as an option.
+     * Unless you compile with -DGNU_STANDARD=0, this program will behave as
+     * gzip even if it is invoked under the name gunzip or zcat.
+     *
+     * Systems which do not support links can still use -d or -dc.
+     * Ignore an .exe extension for MSDOS, OS/2 and VMS.
+     */
+    if (strncmp (program_name, "un",  2) == 0     /* ungzip, uncompress */
+        || strncmp (program_name, "gun", 3) == 0) /* gunzip */
+        decompress = 1;
+    else if (strequ (program_name + 1, "cat")     /* zcat, pcat, gcat */
+             || strequ (program_name, "gzcat"))   /* gzcat */
+        decompress = to_stdout = 1;
+#endif
+
+    z_suffix = Z_SUFFIX;
+    z_len = strlen(z_suffix);
+
+    while (true) {
+        int optc;
+        int longind = -1;
+
+        if (env_argv)
+          {
+            if (env_argv[optind] && strequ (env_argv[optind], "--"))
+              optc = ENV_OPTION + '-';
+            else
+              {
+                optc = getopt_long (env_argc, env_argv, shortopts, longopts,
+                                    &longind);
+                if (0 <= optc)
+                  optc += ENV_OPTION;
+                else
+                  {
+                    if (optind != env_argc)
+                      {
+                        fprintf (stderr,
+                                 ("%s: %s: non-option in "OPTIONS_VAR
+                                  " environment variable\n"),
+                                 program_name, env_argv[optind]);
+                        try_help ();
+                      }
+
+                    /* Wait until here before warning, so that GZIP='-q'
+                       doesn't warn.  */
+                    if (env_argc != 1 && !quiet)
+                      fprintf (stderr,
+                               ("%s: warning: "OPTIONS_VAR" environment variable"
+                                " is deprecated; use an alias or script\n"),
+                               program_name);
+
+                    /* Start processing ARGC and ARGV instead.  */
+                    free (env_argv);
+                    env_argv = NULL;
+                    optind = 1;
+                    longind = -1;
+                  }
+              }
+          }
+
+        if (!env_argv)
+          optc = getopt_long (argc, argv, shortopts, longopts, &longind);
+        if (optc < 0)
+          break;
+
+        switch (optc) {
+        case 'a':
+            ascii = 1; break;
+        case 'b':
+            maxbits = atoi(optarg);
+            for (; *optarg; optarg++)
+              if (! ('0' <= *optarg && *optarg <= '9'))
+                {
+                  fprintf (stderr, "%s: -b operand is not an integer\n",
+                           program_name);
+                  try_help ();
+                }
+            break;
+        case 'c':
+            to_stdout = 1; break;
+        case 'd':
+            decompress = 1; break;
+        case 'f':
+            force++; break;
+        case 'h': case 'H':
+            help (); finish_out (); break;
+        case 'k':
+            keep = 1; break;
+        case 'l':
+            list = decompress = to_stdout = 1; break;
+        case 'L':
+            license (); finish_out (); break;
+        case 'm': /* undocumented, may change later */
+            no_time = 1; break;
+        case 'M': /* undocumented, may change later */
+            no_time = 0; break;
+        case 'n':
+        case 'n' + ENV_OPTION:
+            no_name = no_time = 1; break;
+        case 'N':
+        case 'N' + ENV_OPTION:
+            no_name = no_time = 0; break;
+        case PRESUME_INPUT_TTY_OPTION:
+            presume_input_tty = true; break;
+        case 'q':
+        case 'q' + ENV_OPTION:
+            quiet = 1; verbose = 0; break;
+        case 'r':
+#if NO_DIR
+            fprintf (stderr, "%s: -r not supported on this system\n",
+                     program_name);
+            try_help ();
+#else
+            recursive = 1;
+#endif
+            break;
+
+        case RSYNCABLE_OPTION:
+        case RSYNCABLE_OPTION + ENV_OPTION:
+            rsync = 1;
+            break;
+        case 'S':
+#ifdef NO_MULTIPLE_DOTS
+            if (*optarg == '.') optarg++;
+#endif
+            z_len = strlen(optarg);
+            z_suffix = optarg;
+            break;
+        case SYNCHRONOUS_OPTION:
+            synchronous = true;
+            break;
+        case 't':
+            test = decompress = to_stdout = 1;
+            break;
+        case 'v':
+        case 'v' + ENV_OPTION:
+            verbose++; quiet = 0; break;
+        case 'V':
+            version (); finish_out (); break;
+        case 'Z':
+#ifdef LZW
+            do_lzw = 1; break;
+#else
+            fprintf(stderr, "%s: -Z not supported in this version\n",
+                    program_name);
+            try_help ();
+            break;
+#endif
+        case '1' + ENV_OPTION:  case '2' + ENV_OPTION:  case '3' + ENV_OPTION:
+        case '4' + ENV_OPTION:  case '5' + ENV_OPTION:  case '6' + ENV_OPTION:
+        case '7' + ENV_OPTION:  case '8' + ENV_OPTION:  case '9' + ENV_OPTION:
+            optc -= ENV_OPTION;
+            /* Fall through.  */
+        case '1':  case '2':  case '3':  case '4':
+        case '5':  case '6':  case '7':  case '8':  case '9':
+            level = optc - '0';
+            break;
+
+        default:
+            if (ENV_OPTION <= optc && optc != ENV_OPTION + '?')
+              {
+                /* Output a diagnostic, since getopt_long didn't.  */
+                fprintf (stderr, "%s: ", program_name);
+                if (longind < 0)
+                  fprintf (stderr, "-%c: ", optc - ENV_OPTION);
+                else
+                  fprintf (stderr, "--%s: ", longopts[longind].name);
+                fprintf (stderr, ("option not valid in "OPTIONS_VAR
+                                  " environment variable\n"));
+              }
+            try_help ();
+        }
+    } /* loop on all arguments */
+
+    /* By default, save name and timestamp on compression but do not
+     * restore them on decompression.
+     */
+    if (no_time < 0) no_time = decompress;
+    if (no_name < 0) no_name = decompress;
+
+    file_count = argc - optind;
+
+#if O_BINARY
+#else
+    if (ascii && !quiet) {
+        fprintf(stderr, "%s: option --ascii ignored on this system\n",
+                program_name);
+    }
+#endif
+    if (z_len == 0 || z_len > MAX_SUFFIX) {
+        fprintf(stderr, "%s: invalid suffix '%s'\n", program_name, z_suffix);
+        do_exit(ERROR);
+    }
+
+    if (do_lzw && !decompress) work = lzw;
+
+    /* Allocate all global buffers (for DYN_ALLOC option) */
+    ALLOC(uch, inbuf,  INBUFSIZ +INBUF_EXTRA);
+    ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
+    ALLOC(ush, d_buf,  DIST_BUFSIZE);
+    ALLOC(uch, window, 2L*WSIZE);
+#ifndef MAXSEG_64K
+    ALLOC(ush, tab_prefix, 1L<<BITS);
+#else
+    ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
+    ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
+#endif
+
+    exiting_signal = quiet ? SIGPIPE : 0;
+    install_signal_handlers ();
+
+    /* And get to work */
+    if (file_count != 0) {
+        if (to_stdout && !test && !list && (!decompress || !ascii)) {
+            SET_BINARY_MODE (STDOUT_FILENO);
+        }
+        while (optind < argc) {
+            treat_file(argv[optind++]);
+        }
+    } else {  /* Standard input */
+        treat_stdin();
+    }
+    if (stdin_was_read && close (STDIN_FILENO) != 0)
+      {
+        strcpy (ifname, "stdin");
+        read_error ();
+      }
+    if (list)
+      {
+        /* Output any totals, and check for output errors.  */
+        if (!quiet && 1 < file_count)
+          do_list (-1, -1);
+        if (fflush (stdout) != 0)
+          write_error ();
+      }
+    if (to_stdout
+        && ((synchronous
+             && fdatasync (STDOUT_FILENO) != 0 && errno != EINVAL)
+            || close (STDOUT_FILENO) != 0)
+        && errno != EBADF)
+      write_error ();
+    do_exit(exit_code);
+    return exit_code; /* just to avoid lint warning */
+}
+
+/* Return nonzero when at end of file on input.  */
+local int
+input_eof ()
+{
+  if (!decompress || last_member)
+    return 1;
+
+  if (inptr == insize)
+    {
+      if (insize != INBUFSIZ || fill_inbuf (1) == EOF)
+        return 1;
+
+      /* Unget the char that fill_inbuf got.  */
+      inptr = 0;
+    }
+
+  return 0;
+}
+
+/* ========================================================================
+ * Compress or decompress stdin
+ */
+local void treat_stdin()
+{
+    if (!force && !list
+        && (presume_input_tty
+            || isatty (decompress ? STDIN_FILENO : STDOUT_FILENO))) {
+        /* Do not send compressed data to the terminal or read it from
+         * the terminal. We get here when user invoked the program
+         * without parameters, so be helpful. According to the GNU standards:
+         *
+         *   If there is one behavior you think is most useful when the output
+         *   is to a terminal, and another that you think is most useful when
+         *   the output is a file or a pipe, then it is usually best to make
+         *   the default behavior the one that is useful with output to a
+         *   terminal, and have an option for the other behavior.
+         *
+         * Here we use the --force option to get the other behavior.
+         */
+        if (! quiet)
+          fprintf (stderr,
+                   ("%s: compressed data not %s a terminal."
+                    " Use -f to force %scompression.\n"
+                    "For help, type: %s -h\n"),
+                   program_name,
+                   decompress ? "read from" : "written to",
+                   decompress ? "de" : "",
+                   program_name);
+        do_exit(ERROR);
+    }
+
+    if (decompress || !ascii) {
+      SET_BINARY_MODE (STDIN_FILENO);
+    }
+    if (!test && !list && (!decompress || !ascii)) {
+      SET_BINARY_MODE (STDOUT_FILENO);
+    }
+    strcpy(ifname, "stdin");
+    strcpy(ofname, "stdout");
+
+    /* Get the file's time stamp and size.  */
+    if (fstat (STDIN_FILENO, &istat) != 0)
+      {
+        progerror ("standard input");
+        do_exit (ERROR);
+      }
+    ifile_size = S_ISREG (istat.st_mode) ? istat.st_size : -1;
+    time_stamp.tv_nsec = -1;
+    if (!no_time || list)
+      {
+        if (S_ISREG (istat.st_mode))
+          time_stamp = get_stat_mtime (&istat);
+        else
+          gettime (&time_stamp);
+      }
+
+    clear_bufs(); /* clear input and output buffers */
+    to_stdout = 1;
+    part_nb = 0;
+    ifd = STDIN_FILENO;
+    stdin_was_read = true;
+
+    if (decompress) {
+        method = get_method(ifd);
+        if (method < 0) {
+            do_exit(exit_code); /* error message already emitted */
+        }
+    }
+    if (list) {
+        do_list(ifd, method);
+        return;
+    }
+
+    /* Actually do the compression/decompression. Loop over zipped members.
+     */
+    for (;;) {
+        if (work (STDIN_FILENO, STDOUT_FILENO) != OK)
+          return;
+
+        if (input_eof ())
+          break;
+
+        method = get_method(ifd);
+        if (method < 0) return; /* error message already emitted */
+        bytes_out = 0;            /* required for length check */
+    }
+
+    if (verbose) {
+        if (test) {
+            fprintf(stderr, " OK\n");
+
+        } else if (!decompress) {
+            display_ratio(bytes_in-(bytes_out-header_bytes), bytes_in, stderr);
+            fprintf(stderr, "\n");
+#ifdef DISPLAY_STDIN_RATIO
+        } else {
+            display_ratio(bytes_out-(bytes_in-header_bytes), bytes_out,stderr);
+            fprintf(stderr, "\n");
+#endif
+        }
+    }
+}
+
+static char const dot = '.';
+
+/* True if the cached directory for calls to openat etc. is DIR, with
+   length DIRLEN.  DIR need not be null-terminated.  DIRLEN must be
+   less than MAX_PATH_LEN.  */
+static bool
+atdir_eq (char const *dir, ptrdiff_t dirlen)
+{
+  if (dirlen == 0)
+    dir = &dot, dirlen = 1;
+  return memcmp (dfname, dir, dirlen) == 0 && !dfname[dirlen];
+}
+
+/* Set the directory used for calls to openat etc. to be the directory
+   DIR, with length DIRLEN.  DIR need not be null-terminated.
+   DIRLEN must be less than MAX_PATH_LEN.  Return a file descriptor for
+   the directory, or -1 if one could not be obtained.  */
+static int
+atdir_set (char const *dir, ptrdiff_t dirlen)
+{
+  /* Don't bother opening directories on older systems that
+     lack openat and unlinkat.  It's not worth the porting hassle.  */
+  #if HAVE_OPENAT && HAVE_UNLINKAT
+    enum { try_opening_directories = true };
+  #else
+    enum { try_opening_directories = false };
+  #endif
+
+  if (try_opening_directories && ! atdir_eq (dir, dirlen))
+    {
+      if (0 <= dfd)
+        close (dfd);
+      if (dirlen == 0)
+        dir = &dot, dirlen = 1;
+      memcpy (dfname, dir, dirlen);
+      dfname[dirlen] = '\0';
+      dfd = open (dfname, O_SEARCH | O_DIRECTORY);
+    }
+
+  return dfd;
+}
+
+/* ========================================================================
+ * Compress or decompress the given file
+ */
+local void treat_file(iname)
+    char *iname;
+{
+    /* Accept "-" as synonym for stdin */
+    if (strequ(iname, "-")) {
+        int cflag = to_stdout;
+        treat_stdin();
+        to_stdout = cflag;
+        return;
+    }
+
+    /* Check if the input file is present, set ifname and istat: */
+    ifd = open_input_file (iname, &istat);
+    if (ifd < 0)
+      return;
+
+    /* If the input name is that of a directory, recurse or ignore: */
+    if (S_ISDIR(istat.st_mode)) {
+#if ! NO_DIR
+        if (recursive) {
+            treat_dir (ifd, iname);
+            /* Warning: ifname is now garbage */
+            return;
+        }
+#endif
+        close (ifd);
+        WARN ((stderr, "%s: %s is a directory -- ignored\n",
+               program_name, ifname));
+        return;
+    }
+
+    if (! to_stdout)
+      {
+        if (! S_ISREG (istat.st_mode))
+          {
+            WARN ((stderr,
+                   "%s: %s is not a directory or a regular file - ignored\n",
+                   program_name, ifname));
+            close (ifd);
+            return;
+          }
+        if (istat.st_mode & S_ISUID)
+          {
+            WARN ((stderr, "%s: %s is set-user-ID on execution - ignored\n",
+                   program_name, ifname));
+            close (ifd);
+            return;
+          }
+        if (istat.st_mode & S_ISGID)
+          {
+            WARN ((stderr, "%s: %s is set-group-ID on execution - ignored\n",
+                   program_name, ifname));
+            close (ifd);
+            return;
+          }
+
+        if (! force)
+          {
+            if (istat.st_mode & S_ISVTX)
+              {
+                WARN ((stderr,
+                       "%s: %s has the sticky bit set - file ignored\n",
+                       program_name, ifname));
+                close (ifd);
+                return;
+              }
+            if (2 <= istat.st_nlink)
+              {
+                WARN ((stderr, "%s: %s has %lu other link%c -- unchanged\n",
+                       program_name, ifname,
+                       (unsigned long int) istat.st_nlink - 1,
+                       istat.st_nlink == 2 ? ' ' : 's'));
+                close (ifd);
+                return;
+              }
+          }
+      }
+
+    ifile_size = S_ISREG (istat.st_mode) ? istat.st_size : -1;
+    time_stamp.tv_nsec = -1;
+    if (!no_time || list)
+      time_stamp = get_stat_mtime (&istat);
+
+    /* Generate output file name. For -r and (-t or -l), skip files
+     * without a valid gzip suffix (check done in make_ofname).
+     */
+    if (to_stdout && !list && !test) {
+        strcpy(ofname, "stdout");
+
+    } else if (make_ofname() != OK) {
+        close (ifd);
+        return;
+    }
+
+    clear_bufs(); /* clear input and output buffers */
+    part_nb = 0;
+
+    if (decompress) {
+        method = get_method(ifd); /* updates ofname if original given */
+        if (method < 0) {
+            close(ifd);
+            return;               /* error message already emitted */
+        }
+    }
+    if (list) {
+        do_list(ifd, method);
+        if (close (ifd) != 0)
+          read_error ();
+        return;
+    }
+
+    /* If compressing to a file, check if ofname is not ambiguous
+     * because the operating system truncates names. Otherwise, generate
+     * a new ofname and save the original name in the compressed file.
+     */
+    if (to_stdout) {
+        ofd = STDOUT_FILENO;
+        /* Keep remove_ofname_fd negative.  */
+    } else {
+        if (create_outfile() != OK) return;
+
+        if (!decompress && save_orig_name && !verbose && !quiet) {
+            fprintf(stderr, "%s: %s compressed to %s\n",
+                    program_name, ifname, ofname);
+        }
+    }
+    /* Keep the name even if not truncated except with --no-name: */
+    if (!save_orig_name) save_orig_name = !no_name;
+
+    if (verbose) {
+        fprintf(stderr, "%s:\t", ifname);
+    }
+
+    /* Actually do the compression/decompression. Loop over zipped members.
+     */
+    for (;;) {
+        if ((*work)(ifd, ofd) != OK) {
+            method = -1; /* force cleanup */
+            break;
+        }
+
+        if (input_eof ())
+          break;
+
+        method = get_method(ifd);
+        if (method < 0) break;    /* error message already emitted */
+        bytes_out = 0;            /* required for length check */
+    }
+
+    if (close (ifd) != 0)
+      read_error ();
+
+    if (!to_stdout)
+      {
+        copy_stat (&istat);
+
+        if ((synchronous
+             && ((0 <= dfd && fdatasync (dfd) != 0 && errno != EINVAL)
+                 || (fsync (ofd) != 0 && errno != EINVAL)))
+            || close (ofd) != 0)
+          write_error ();
+
+        if (!keep)
+          {
+            sigset_t oldset;
+            int unlink_errno;
+            char *ifbase = last_component (ifname);
+            int ufd = atdir_eq (ifname, ifbase - ifname) ? dfd : -1;
+            int res;
+
+            sigprocmask (SIG_BLOCK, &caught_signals, &oldset);
+            remove_ofname_fd = -1;
+            res = ufd < 0 ? xunlink (ifname) : unlinkat (ufd, ifbase, 0);
+            unlink_errno = res == 0 ? 0 : errno;
+            sigprocmask (SIG_SETMASK, &oldset, NULL);
+
+            if (unlink_errno)
+              {
+                WARN ((stderr, "%s: ", program_name));
+                if (!quiet)
+                  {
+                    errno = unlink_errno;
+                    perror (ifname);
+                  }
+              }
+          }
+      }
+
+    if (method == -1) {
+        if (!to_stdout)
+          remove_output_file ();
+        return;
+    }
+
+    /* Display statistics */
+    if(verbose) {
+        if (test) {
+            fprintf(stderr, " OK");
+        } else if (decompress) {
+            display_ratio(bytes_out-(bytes_in-header_bytes), bytes_out,stderr);
+        } else {
+            display_ratio(bytes_in-(bytes_out-header_bytes), bytes_in, stderr);
+        }
+        if (!test && !to_stdout)
+          fprintf(stderr, " -- %s %s", keep ? "created" : "replaced with",
+                  ofname);
+        fprintf(stderr, "\n");
+    }
+}
+
+/* ========================================================================
+ * Create the output file. Return OK or ERROR.
+ * Try several times if necessary to avoid truncating the z_suffix. For
+ * example, do not create a compressed file of name "1234567890123."
+ * Sets save_orig_name to true if the file name has been truncated.
+ * IN assertions: the input file has already been open (ifd is set) and
+ *   ofname has already been updated if there was an original name.
+ * OUT assertions: ifd and ofd are closed in case of error.
+ */
+local int create_outfile()
+{
+  int name_shortened = 0;
+  int flags = (O_WRONLY | O_CREAT | O_EXCL
+               | (ascii && decompress ? 0 : O_BINARY));
+  char const *base = ofname;
+  int atfd = AT_FDCWD;
+
+  if (!keep)
+    {
+      char const *b = last_component (ofname);
+      int f = atdir_set (ofname, b - ofname);
+      if (0 <= f)
+        {
+          base = b;
+          atfd = f;
+        }
+    }
+
+  for (;;)
+    {
+      int open_errno;
+      sigset_t oldset;
+
+      sigprocmask (SIG_BLOCK, &caught_signals, &oldset);
+      remove_ofname_fd = ofd = openat (atfd, base, flags, S_IRUSR | S_IWUSR);
+      open_errno = errno;
+      sigprocmask (SIG_SETMASK, &oldset, NULL);
+
+      if (0 <= ofd)
+        break;
+
+      switch (open_errno)
+        {
+#ifdef ENAMETOOLONG
+        case ENAMETOOLONG:
+          shorten_name (ofname);
+          name_shortened = 1;
+          break;
+#endif
+
+        case EEXIST:
+          if (check_ofname () != OK)
+            {
+              close (ifd);
+              return ERROR;
+            }
+          break;
+
+        default:
+          progerror (ofname);
+          close (ifd);
+          return ERROR;
+        }
+    }
+
+  if (name_shortened && decompress)
+    {
+      /* name might be too long if an original name was saved */
+      WARN ((stderr, "%s: %s: warning, name truncated\n",
+             program_name, ofname));
+    }
+
+  return OK;
+}
+
+/* ========================================================================
+ * Return a pointer to the 'z' suffix of a file name, or NULL. For all
+ * systems, ".gz", ".z", ".Z", ".taz", ".tgz", "-gz", "-z" and "_z" are
+ * accepted suffixes, in addition to the value of the --suffix option.
+ * ".tgz" is a useful convention for tar.z files on systems limited
+ * to 3 characters extensions. On such systems, ".?z" and ".??z" are
+ * also accepted suffixes. For Unix, we do not want to accept any
+ * .??z suffix as indicating a compressed file; some people use .xyz
+ * to denote volume data.
+ *   On systems allowing multiple versions of the same file (such as VMS),
+ * this function removes any version suffix in the given name.
+ */
+local char *get_suffix(name)
+    char *name;
+{
+    int nlen, slen;
+    char suffix[MAX_SUFFIX+3]; /* last chars of name, forced to lower case */
+    static char const *known_suffixes[] =
+       {NULL, ".gz", ".z", ".taz", ".tgz", "-gz", "-z", "_z",
+#ifdef MAX_EXT_CHARS
+          "z",
+#endif
+        NULL, NULL};
+    char const **suf;
+    bool suffix_of_builtin = false;
+
+    /* Normally put Z_SUFFIX at the start of KNOWN_SUFFIXES, but if it
+       is a suffix of one of them, put it at the end.  */
+    for (suf = known_suffixes + 1; *suf; suf++)
+      {
+        size_t suflen = strlen (*suf);
+        if (z_len < suflen && strequ (z_suffix, *suf + suflen - z_len))
+          {
+            suffix_of_builtin = true;
+            break;
+          }
+      }
+    known_suffixes[suffix_of_builtin
+                   ? sizeof known_suffixes / sizeof *known_suffixes - 2
+                   : 0] = z_suffix;
+    suf = known_suffixes + suffix_of_builtin;
+
+#ifdef SUFFIX_SEP
+    /* strip a version number from the file name */
+    {
+        char *v = strrchr(name, SUFFIX_SEP);
+        if (v != NULL) *v = '\0';
+    }
+#endif
+    nlen = strlen(name);
+    if (nlen <= MAX_SUFFIX+2) {
+        strcpy(suffix, name);
+    } else {
+        strcpy(suffix, name+nlen-MAX_SUFFIX-2);
+    }
+    strlwr(suffix);
+    slen = strlen(suffix);
+    do {
+       int s = strlen(*suf);
+       if (slen > s && suffix[slen-s-1] != PATH_SEP
+           && strequ(suffix + slen - s, *suf)) {
+           return name+nlen-s;
+       }
+    } while (*++suf != NULL);
+
+    return NULL;
+}
+
+
+/* Open file NAME with the given flags and store its status
+   into *ST.  Return a file descriptor to the newly opened file, or -1
+   (setting errno) on failure.  */
+static int
+open_and_stat (char *name, int flags, struct stat *st)
+{
+  int fd;
+  int atfd = AT_FDCWD;
+  char const *base = name;
+
+  /* Refuse to follow symbolic links unless -c or -f.  */
+  if (!to_stdout && !force)
+    {
+      if (HAVE_WORKING_O_NOFOLLOW)
+        flags |= O_NOFOLLOW;
+      else
+        {
+#if HAVE_LSTAT || defined lstat
+          if (lstat (name, st) != 0)
+            return -1;
+          else if (S_ISLNK (st->st_mode))
+            {
+              errno = ELOOP;
+              return -1;
+            }
+#endif
+        }
+    }
+
+  if (!keep)
+    {
+      char const *b = last_component (name);
+      int f = atdir_set (name, b - name);
+      if (0 <= f)
+        {
+          base = b;
+          atfd = f;
+        }
+    }
+
+  fd = openat (atfd, base, flags);
+  if (0 <= fd && fstat (fd, st) != 0)
+    {
+      int e = errno;
+      close (fd);
+      errno = e;
+      return -1;
+    }
+  return fd;
+}
+
+
+/* ========================================================================
+ * Set ifname to the input file name (with a suffix appended if necessary)
+ * and istat to its stats. For decompression, if no file exists with the
+ * original name, try adding successively z_suffix, .gz, .z, -z and .Z.
+ * For MSDOS, we try only z_suffix and z.
+ * Return an open file descriptor or -1.
+ */
+static int
+open_input_file (iname, sbuf)
+    char *iname;
+    struct stat *sbuf;
+{
+    int ilen;  /* strlen(ifname) */
+    int z_suffix_errno = 0;
+    static char const *suffixes[] = {NULL, ".gz", ".z", "-z", ".Z", NULL};
+    char const **suf = suffixes;
+    char const *s;
+#ifdef NO_MULTIPLE_DOTS
+    char *dot; /* pointer to ifname extension, or NULL */
+#endif
+    int fd;
+    int open_flags = (O_RDONLY | O_NONBLOCK | O_NOCTTY
+                      | (ascii && !decompress ? 0 : O_BINARY));
+
+    *suf = z_suffix;
+
+    if (sizeof ifname - 1 <= strlen (iname))
+        goto name_too_long;
+
+    strcpy(ifname, iname);
+
+    /* If input file exists, return OK. */
+    fd = open_and_stat (ifname, open_flags, sbuf);
+    if (0 <= fd)
+      return fd;
+
+    if (!decompress || errno != ENOENT) {
+        progerror(ifname);
+        return -1;
+    }
+    /* file.ext doesn't exist, try adding a suffix (after removing any
+     * version number for VMS).
+     */
+    s = get_suffix(ifname);
+    if (s != NULL) {
+        progerror(ifname); /* ifname already has z suffix and does not exist */
+        return -1;
+    }
+#ifdef NO_MULTIPLE_DOTS
+    dot = strrchr(ifname, '.');
+    if (dot == NULL) {
+        strcat(ifname, ".");
+        dot = strrchr(ifname, '.');
+    }
+#endif
+    ilen = strlen(ifname);
+    if (strequ(z_suffix, ".gz")) suf++;
+
+    /* Search for all suffixes */
+    do {
+        char const *s0 = s = *suf;
+        strcpy (ifname, iname);
+#ifdef NO_MULTIPLE_DOTS
+        if (*s == '.') s++;
+        if (*dot == '\0') strcpy (dot, ".");
+#endif
+#ifdef MAX_EXT_CHARS
+        if (MAX_EXT_CHARS < strlen (s) + strlen (dot + 1))
+          dot[MAX_EXT_CHARS + 1 - strlen (s)] = '\0';
+#endif
+        if (sizeof ifname <= ilen + strlen (s))
+          goto name_too_long;
+        strcat(ifname, s);
+        fd = open_and_stat (ifname, open_flags, sbuf);
+        if (0 <= fd)
+          return fd;
+        if (errno != ENOENT)
+          {
+            progerror (ifname);
+            return -1;
+          }
+        if (strequ (s0, z_suffix))
+          z_suffix_errno = errno;
+    } while (*++suf != NULL);
+
+    /* No suffix found, complain using z_suffix: */
+    strcpy(ifname, iname);
+#ifdef NO_MULTIPLE_DOTS
+    if (*dot == '\0') strcpy(dot, ".");
+#endif
+#ifdef MAX_EXT_CHARS
+    if (MAX_EXT_CHARS < z_len + strlen (dot + 1))
+      dot[MAX_EXT_CHARS + 1 - z_len] = '\0';
+#endif
+    strcat(ifname, z_suffix);
+    errno = z_suffix_errno;
+    progerror(ifname);
+    return -1;
+
+ name_too_long:
+    fprintf (stderr, "%s: %s: file name too long\n", program_name, iname);
+    exit_code = ERROR;
+    return -1;
+}
+
+/* ========================================================================
+ * Generate ofname given ifname. Return OK, or WARNING if file must be skipped.
+ * Sets save_orig_name to true if the file name has been truncated.
+ */
+local int make_ofname()
+{
+    char *suff;            /* ofname z suffix */
+
+    strcpy(ofname, ifname);
+    /* strip a version number if any and get the gzip suffix if present: */
+    suff = get_suffix(ofname);
+
+    if (decompress) {
+        if (suff == NULL) {
+            /* With -t or -l, try all files (even without .gz suffix)
+             * except with -r (behave as with just -dr).
+             */
+            if (!recursive && (list || test)) return OK;
+
+            /* Avoid annoying messages with -r */
+            if (verbose || (!recursive && !quiet)) {
+                WARN((stderr,"%s: %s: unknown suffix -- ignored\n",
+                      program_name, ifname));
+            }
+            return WARNING;
+        }
+        /* Make a special case for .tgz and .taz: */
+        strlwr(suff);
+        if (strequ(suff, ".tgz") || strequ(suff, ".taz")) {
+            strcpy(suff, ".tar");
+        } else {
+            *suff = '\0'; /* strip the z suffix */
+        }
+        /* ofname might be changed later if infile contains an original name */
+
+    } else if (suff && ! force) {
+        /* Avoid annoying messages with -r (see treat_dir()) */
+        if (verbose || (!recursive && !quiet)) {
+            /* Don't use WARN, as it affects exit status.  */
+            fprintf (stderr, "%s: %s already has %s suffix -- unchanged\n",
+                     program_name, ifname, suff);
+        }
+        return WARNING;
+    } else {
+        save_orig_name = 0;
+
+#ifdef NO_MULTIPLE_DOTS
+        suff = strrchr(ofname, '.');
+        if (suff == NULL) {
+            if (sizeof ofname <= strlen (ofname) + 1)
+                goto name_too_long;
+            strcat(ofname, ".");
+#  ifdef MAX_EXT_CHARS
+            if (strequ(z_suffix, "z")) {
+                if (sizeof ofname <= strlen (ofname) + 2)
+                    goto name_too_long;
+                strcat(ofname, "gz"); /* enough room */
+                return OK;
+            }
+        /* On the Atari and some versions of MSDOS,
+         * ENAMETOOLONG does not work correctly.  So we
+         * must truncate here.
+         */
+        } else if (strlen(suff)-1 + z_len > MAX_SUFFIX) {
+            suff[MAX_SUFFIX+1-z_len] = '\0';
+            save_orig_name = 1;
+#  endif
+        }
+#endif /* NO_MULTIPLE_DOTS */
+        if (sizeof ofname <= strlen (ofname) + z_len)
+            goto name_too_long;
+        strcat(ofname, z_suffix);
+
+    } /* decompress ? */
+    return OK;
+
+ name_too_long:
+    WARN ((stderr, "%s: %s: file name too long\n", program_name, ifname));
+    return WARNING;
+}
+
+/* Discard NBYTES input bytes from the input, or up through the next
+   zero byte if NBYTES == (size_t) -1.  If FLAGS say that the header
+   CRC should be computed, update the CRC accordingly.  */
+static void
+discard_input_bytes (nbytes, flags)
+    size_t nbytes;
+    unsigned int flags;
+{
+  while (nbytes != 0)
+    {
+      uch c = get_byte ();
+      if (flags & HEADER_CRC)
+        updcrc (&c, 1);
+      if (nbytes != (size_t) -1)
+        nbytes--;
+      else if (! c)
+        break;
+    }
+}
+
+/* ========================================================================
+ * Check the magic number of the input file and update ofname if an
+ * original name was given and to_stdout is not set.
+ * Return the compression method, -1 for error, -2 for warning.
+ * Set inptr to the offset of the next byte to be processed.
+ * Updates time_stamp if there is one and --no-time is not used.
+ * This function may be called repeatedly for an input file consisting
+ * of several contiguous gzip'ed members.
+ * IN assertions: there is at least one remaining compressed member.
+ *   If the member is a zip file, it must be the only one.
+ */
+local int get_method(in)
+    int in;        /* input file descriptor */
+{
+    uch flags;     /* compression flags */
+    uch magic[10]; /* magic header */
+    int imagic0;   /* first magic byte or EOF */
+    int imagic1;   /* like magic[1], but can represent EOF */
+    ulg stamp;     /* time stamp */
+
+    /* If --force and --stdout, zcat == cat, so do not complain about
+     * premature end of file: use try_byte instead of get_byte.
+     */
+    if (force && to_stdout) {
+        imagic0 = try_byte();
+        magic[0] = imagic0;
+        imagic1 = try_byte ();
+        magic[1] = imagic1;
+        /* If try_byte returned EOF, magic[1] == (char) EOF.  */
+    } else {
+        magic[0] = get_byte ();
+        imagic0 = 0;
+        if (magic[0]) {
+            magic[1] = get_byte ();
+            imagic1 = 0; /* avoid lint warning */
+        } else {
+            imagic1 = try_byte ();
+            magic[1] = imagic1;
+        }
+    }
+    method = -1;                 /* unknown yet */
+    part_nb++;                   /* number of parts in gzip file */
+    header_bytes = 0;
+    last_member = RECORD_IO;
+    /* assume multiple members in gzip file except for record oriented I/O */
+
+    if (memcmp(magic, GZIP_MAGIC, 2) == 0
+        || memcmp(magic, OLD_GZIP_MAGIC, 2) == 0) {
+
+        method = (int)get_byte();
+        if (method != DEFLATED) {
+            fprintf(stderr,
+                    "%s: %s: unknown method %d -- not supported\n",
+                    program_name, ifname, method);
+            exit_code = ERROR;
+            return -1;
+        }
+        work = unzip;
+        flags  = (uch)get_byte();
+
+        if ((flags & ENCRYPTED) != 0) {
+            fprintf(stderr,
+                    "%s: %s is encrypted -- not supported\n",
+                    program_name, ifname);
+            exit_code = ERROR;
+            return -1;
+        }
+        if ((flags & RESERVED) != 0) {
+            fprintf(stderr,
+                    "%s: %s has flags 0x%x -- not supported\n",
+                    program_name, ifname, flags);
+            exit_code = ERROR;
+            if (force <= 1) return -1;
+        }
+        stamp  = (ulg)get_byte();
+        stamp |= ((ulg)get_byte()) << 8;
+        stamp |= ((ulg)get_byte()) << 16;
+        stamp |= ((ulg)get_byte()) << 24;
+        if (stamp != 0 && !no_time)
+          {
+            time_stamp.tv_sec = stamp;
+            time_stamp.tv_nsec = 0;
+          }
+
+        magic[8] = get_byte ();  /* Ignore extra flags.  */
+        magic[9] = get_byte ();  /* Ignore OS type.  */
+
+        if (flags & HEADER_CRC)
+          {
+            magic[2] = DEFLATED;
+            magic[3] = flags;
+            magic[4] = stamp & 0xff;
+            magic[5] = (stamp >> 8) & 0xff;
+            magic[6] = (stamp >> 16) & 0xff;
+            magic[7] = stamp >> 24;
+            updcrc (NULL, 0);
+            updcrc (magic, 10);
+          }
+
+        if ((flags & EXTRA_FIELD) != 0) {
+            uch lenbuf[2];
+            unsigned int len = lenbuf[0] = get_byte ();
+            len |= (lenbuf[1] = get_byte ()) << 8;
+            if (verbose) {
+                fprintf(stderr,"%s: %s: extra field of %u bytes ignored\n",
+                        program_name, ifname, len);
+            }
+            if (flags & HEADER_CRC)
+              updcrc (lenbuf, 2);
+            discard_input_bytes (len, flags);
+        }
+
+        /* Get original file name if it was truncated */
+        if ((flags & ORIG_NAME) != 0) {
+            if (no_name || (to_stdout && !list) || part_nb > 1) {
+                /* Discard the old name */
+                discard_input_bytes (-1, flags);
+            } else {
+                /* Copy the base name. Keep a directory prefix intact. */
+                char *p = gzip_base_name (ofname);
+                char *base = p;
+                for (;;) {
+                    *p = (char) get_byte ();
+                    if (*p++ == '\0') break;
+                    if (p >= ofname+sizeof(ofname)) {
+                        gzip_error ("corrupted input -- file name too large");
+                    }
+                }
+                if (flags & HEADER_CRC)
+                  updcrc ((uch *) base, p - base);
+                p = gzip_base_name (base);
+                memmove (base, p, strlen (p) + 1);
+                /* If necessary, adapt the name to local OS conventions: */
+                if (!list) {
+                   MAKE_LEGAL_NAME(base);
+                   if (base) list=0; /* avoid warning about unused variable */
+                }
+            } /* no_name || to_stdout */
+        } /* ORIG_NAME */
+
+        /* Discard file comment if any */
+        if ((flags & COMMENT) != 0) {
+            discard_input_bytes (-1, flags);
+        }
+
+        if (flags & HEADER_CRC)
+          {
+            unsigned int crc16 = updcrc (magic, 0) & 0xffff;
+            unsigned int header16 = get_byte ();
+            header16 |= ((unsigned int) get_byte ()) << 8;
+            if (header16 != crc16)
+              {
+                fprintf (stderr,
+                         "%s: %s: header checksum 0x%04x != computed checksum 0x%04x\n",
+                         program_name, ifname, header16, crc16);
+                exit_code = ERROR;
+                if (force <= 1)
+                  return -1;
+              }
+          }
+
+        if (part_nb == 1) {
+            header_bytes = inptr + 2*4; /* include crc and size */
+        }
+
+    } else if (memcmp(magic, PKZIP_MAGIC, 2) == 0 && inptr == 2
+            && memcmp((char*)inbuf, PKZIP_MAGIC, 4) == 0) {
+        /* To simplify the code, we support a zip file when alone only.
+         * We are thus guaranteed that the entire local header fits in inbuf.
+         */
+        inptr = 0;
+        work = unzip;
+        if (check_zipfile(in) != OK) return -1;
+        /* check_zipfile may get ofname from the local header */
+        last_member = 1;
+
+    } else if (memcmp(magic, PACK_MAGIC, 2) == 0) {
+        work = unpack;
+        method = PACKED;
+
+    } else if (memcmp(magic, LZW_MAGIC, 2) == 0) {
+        work = unlzw;
+        method = COMPRESSED;
+        last_member = 1;
+
+    } else if (memcmp(magic, LZH_MAGIC, 2) == 0) {
+        work = unlzh;
+        method = LZHED;
+        last_member = 1;
+
+    } else if (force && to_stdout && !list) { /* pass input unchanged */
+        method = STORED;
+        work = copy;
+        if (imagic1 != EOF)
+            inptr--;
+        last_member = 1;
+        if (imagic0 != EOF) {
+            write_buf (STDOUT_FILENO, magic, 1);
+            bytes_out++;
+        }
+    }
+    if (method >= 0) return method;
+
+    if (part_nb == 1) {
+        fprintf (stderr, "\n%s: %s: not in gzip format\n",
+                 program_name, ifname);
+        exit_code = ERROR;
+        return -1;
+    } else {
+        if (magic[0] == 0)
+          {
+            int inbyte;
+            for (inbyte = imagic1;  inbyte == 0;  inbyte = try_byte ())
+              continue;
+            if (inbyte == EOF)
+              {
+                if (verbose)
+                  WARN ((stderr, "\n%s: %s: decompression OK, trailing zero bytes ignored\n",
+                         program_name, ifname));
+                return -3;
+              }
+          }
+
+        WARN((stderr, "\n%s: %s: decompression OK, trailing garbage ignored\n",
+              program_name, ifname));
+        return -2;
+    }
+}
+
+/* ========================================================================
+ * Display the characteristics of the compressed file.
+ * If the given method is < 0, display the accumulated totals.
+ * IN assertions: time_stamp, header_bytes and ifile_size are initialized.
+ */
+local void do_list(ifd, method)
+    int ifd;     /* input file descriptor */
+    int method;  /* compression method */
+{
+    ulg crc;  /* original crc */
+    static int first_time = 1;
+    static char const *const methods[MAX_METHODS] = {
+        "store",  /* 0 */
+        "compr",  /* 1 */
+        "pack ",  /* 2 */
+        "lzh  ",  /* 3 */
+        "", "", "", "", /* 4 to 7 reserved */
+        "defla"}; /* 8 */
+    int positive_off_t_width = 1;
+    off_t o;
+
+    for (o = OFF_T_MAX;  9 < o;  o /= 10) {
+        positive_off_t_width++;
+    }
+
+    if (first_time && method >= 0) {
+        first_time = 0;
+        if (verbose)  {
+            printf("method  crc     date  time  ");
+        }
+        if (!quiet) {
+            printf("%*.*s %*.*s  ratio uncompressed_name\n",
+                   positive_off_t_width, positive_off_t_width, "compressed",
+                   positive_off_t_width, positive_off_t_width, "uncompressed");
+        }
+    } else if (method < 0) {
+        if (total_in <= 0 || total_out <= 0) return;
+        if (verbose) {
+            printf("                            ");
+        }
+        if (verbose || !quiet) {
+            fprint_off(stdout, total_in, positive_off_t_width);
+            printf(" ");
+            fprint_off(stdout, total_out, positive_off_t_width);
+            printf(" ");
+        }
+        display_ratio(total_out-(total_in-header_bytes), total_out, stdout);
+        /* header_bytes is not meaningful but used to ensure the same
+         * ratio if there is a single file.
+         */
+        printf(" (totals)\n");
+        return;
+    }
+    crc = (ulg)~0; /* unknown */
+    bytes_out = -1L;
+    bytes_in = ifile_size;
+
+    if (!RECORD_IO && method == DEFLATED && !last_member) {
+        /* Get the crc and uncompressed size for gzip'ed (not zip'ed) files.
+         * If the lseek fails, we could use read() to get to the end, but
+         * --list is used to get quick results.
+         * Use "gunzip < foo.gz | wc -c" to get the uncompressed size if
+         * you are not concerned about speed.
+         */
+        bytes_in = lseek(ifd, (off_t)(-8), SEEK_END);
+        if (bytes_in != -1L) {
+            uch buf[8];
+            bytes_in += 8L;
+            if (read(ifd, (char*)buf, sizeof(buf)) != sizeof(buf)) {
+                read_error();
+            }
+            crc       = LG(buf);
+            bytes_out = LG(buf+4);
+        }
+    }
+
+    if (verbose)
+      {
+        static char const month_abbr[][4]
+          = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+              "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
+        struct tm *tm = localtime (&time_stamp.tv_sec);
+        printf ("%5s %08lx ", methods[method], crc);
+        if (tm)
+          printf ("%s%3d %02d:%02d ", month_abbr[tm->tm_mon],
+                  tm->tm_mday, tm->tm_hour, tm->tm_min);
+        else
+          printf ("??? ?? ??:?? ");
+      }
+    fprint_off(stdout, bytes_in, positive_off_t_width);
+    printf(" ");
+    fprint_off(stdout, bytes_out, positive_off_t_width);
+    printf(" ");
+    if (bytes_in  == -1L) {
+        total_in = -1L;
+        bytes_in = bytes_out = header_bytes = 0;
+    } else if (total_in >= 0) {
+        total_in  += bytes_in;
+    }
+    if (bytes_out == -1L) {
+        total_out = -1L;
+        bytes_in = bytes_out = header_bytes = 0;
+    } else if (total_out >= 0) {
+        total_out += bytes_out;
+    }
+    display_ratio(bytes_out-(bytes_in-header_bytes), bytes_out, stdout);
+    printf(" %s\n", ofname);
+}
+
+/* ========================================================================
+ * Shorten the given name by one character, or replace a .tar extension
+ * with .tgz. Truncate the last part of the name which is longer than
+ * MIN_PART characters: 1234.678.012.gz -> 123.678.012.gz. If the name
+ * has only parts shorter than MIN_PART truncate the longest part.
+ * For decompression, just remove the last character of the name.
+ *
+ * IN assertion: for compression, the suffix of the given name is z_suffix.
+ */
+local void shorten_name(name)
+    char *name;
+{
+    int len;                 /* length of name without z_suffix */
+    char *trunc = NULL;      /* character to be truncated */
+    int plen;                /* current part length */
+    int min_part = MIN_PART; /* current minimum part length */
+    char *p;
+
+    len = strlen(name);
+    if (decompress) {
+        if (len <= 1)
+          gzip_error ("name too short");
+        name[len-1] = '\0';
+        return;
+    }
+    p = get_suffix(name);
+    if (! p)
+      gzip_error ("can't recover suffix\n");
+    *p = '\0';
+    save_orig_name = 1;
+
+    /* compress 1234567890.tar to 1234567890.tgz */
+    if (len > 4 && strequ(p-4, ".tar")) {
+        strcpy(p-4, ".tgz");
+        return;
+    }
+    /* Try keeping short extensions intact:
+     * 1234.678.012.gz -> 123.678.012.gz
+     */
+    do {
+        p = strrchr(name, PATH_SEP);
+        p = p ? p+1 : name;
+        while (*p) {
+            plen = strcspn(p, PART_SEP);
+            p += plen;
+            if (plen > min_part) trunc = p-1;
+            if (*p) p++;
+        }
+    } while (trunc == NULL && --min_part != 0);
+
+    if (trunc != NULL) {
+        do {
+            trunc[0] = trunc[1];
+        } while (*trunc++);
+        trunc--;
+    } else {
+        trunc = strrchr(name, PART_SEP[0]);
+        if (!trunc)
+          gzip_error ("internal error in shorten_name");
+        if (trunc[1] == '\0') trunc--; /* force truncation */
+    }
+    strcpy(trunc, z_suffix);
+}
+
+/* ========================================================================
+ * The compressed file already exists, so ask for confirmation.
+ * Return ERROR if the file must be skipped.
+ */
+local int check_ofname()
+{
+    /* Ask permission to overwrite the existing file */
+    if (!force) {
+        int ok = 0;
+        fprintf (stderr, "%s: %s already exists;", program_name, ofname);
+        if (foreground && (presume_input_tty || isatty (STDIN_FILENO))) {
+            fprintf(stderr, " do you wish to overwrite (y or n)? ");
+            fflush(stderr);
+            ok = yesno();
+        }
+        if (!ok) {
+            fprintf(stderr, "\tnot overwritten\n");
+            if (exit_code == OK) exit_code = WARNING;
+            return ERROR;
+        }
+    }
+    if (xunlink (ofname)) {
+        progerror(ofname);
+        return ERROR;
+    }
+    return OK;
+}
+
+/* Change the owner and group of a file.  FD is a file descriptor for
+   the file and NAME its name.  Change it to user UID and to group GID.
+   If UID or GID is -1, though, do not change the corresponding user
+   or group.  */
+static void
+do_chown (int fd, char const *name, uid_t uid, gid_t gid)
+{
+#ifndef NO_CHOWN
+# if HAVE_FCHOWN
+  ignore_value (fchown (fd, uid, gid));
+# else
+  ignore_value (chown (name, uid, gid));
+# endif
+#endif
+}
+
+/* ========================================================================
+ * Copy modes, times, ownership from input file to output file.
+ * IN assertion: to_stdout is false.
+ */
+local void copy_stat(ifstat)
+    struct stat *ifstat;
+{
+    mode_t mode = ifstat->st_mode & S_IRWXUGO;
+    int r;
+
+#ifndef NO_UTIME
+    struct timespec timespec[2];
+    timespec[0] = get_stat_atime (ifstat);
+    timespec[1] = get_stat_mtime (ifstat);
+
+    if (decompress && 0 <= time_stamp.tv_nsec
+        && ! (timespec[1].tv_sec == time_stamp.tv_sec
+              && timespec[1].tv_nsec == time_stamp.tv_nsec))
+      {
+        timespec[1] = time_stamp;
+        if (verbose > 1) {
+            fprintf(stderr, "%s: time stamp restored\n", ofname);
+        }
+      }
+
+    if (fdutimens (ofd, ofname, timespec) != 0)
+      {
+        int e = errno;
+        WARN ((stderr, "%s: ", program_name));
+        if (!quiet)
+          {
+            errno = e;
+            perror (ofname);
+          }
+      }
+#endif
+
+    /* Change the group first, then the permissions, then the owner.
+       That way, the permissions will be correct on systems that allow
+       users to give away files, without introducing a security hole.
+       Security depends on permissions not containing the setuid or
+       setgid bits.  */
+
+    do_chown (ofd, ofname, -1, ifstat->st_gid);
+
+#if HAVE_FCHMOD
+    r = fchmod (ofd, mode);
+#else
+    r = chmod (ofname, mode);
+#endif
+    if (r != 0) {
+        int e = errno;
+        WARN ((stderr, "%s: ", program_name));
+        if (!quiet) {
+            errno = e;
+            perror(ofname);
+        }
+    }
+
+    do_chown (ofd, ofname, ifstat->st_uid, -1);
+}
+
+#if ! NO_DIR
+
+/* ========================================================================
+ * Recurse through the given directory.
+ */
+local void treat_dir (fd, dir)
+    int fd;
+    char *dir;
+{
+    DIR      *dirp;
+    char     nbuf[MAX_PATH_LEN];
+    char *entries;
+    char const *entry;
+    size_t entrylen;
+
+    dirp = fdopendir (fd);
+
+    if (dirp == NULL) {
+        progerror(dir);
+        close (fd);
+        return ;
+    }
+
+    entries = streamsavedir (dirp, SAVEDIR_SORT_NONE);
+    if (! entries)
+      progerror (dir);
+    if (closedir (dirp) != 0)
+      progerror (dir);
+    if (! entries)
+      return;
+
+    for (entry = entries; *entry; entry += entrylen + 1) {
+        size_t len = strlen (dir);
+        entrylen = strlen (entry);
+        if (strequ (entry, ".") || strequ (entry, ".."))
+          continue;
+        if (len + entrylen < MAX_PATH_LEN - 2) {
+            strcpy(nbuf,dir);
+            if (len != 0 /* dir = "" means current dir on Amiga */
+#ifdef PATH_SEP2
+                && dir[len-1] != PATH_SEP2
+#endif
+#ifdef PATH_SEP3
+                && dir[len-1] != PATH_SEP3
+#endif
+            ) {
+                nbuf[len++] = PATH_SEP;
+            }
+            strcpy (nbuf + len, entry);
+            treat_file(nbuf);
+        } else {
+            fprintf(stderr,"%s: %s/%s: pathname too long\n",
+                    program_name, dir, entry);
+            exit_code = ERROR;
+        }
+    }
+    free (entries);
+}
+#endif /* ! NO_DIR */
+
+/* Make sure signals get handled properly.  */
+
+static void
+install_signal_handlers ()
+{
+  int nsigs = sizeof handled_sig / sizeof handled_sig[0];
+  int i;
+
+#if SA_NOCLDSTOP
+  struct sigaction act;
+
+  sigemptyset (&caught_signals);
+  for (i = 0; i < nsigs; i++)
+    {
+      sigaction (handled_sig[i], NULL, &act);
+      if (act.sa_handler != SIG_IGN)
+        sigaddset (&caught_signals, handled_sig[i]);
+    }
+
+  act.sa_handler = abort_gzip_signal;
+  act.sa_mask = caught_signals;
+  act.sa_flags = 0;
+
+  for (i = 0; i < nsigs; i++)
+    if (sigismember (&caught_signals, handled_sig[i]))
+      {
+        if (i == 0)
+          foreground = 1;
+        sigaction (handled_sig[i], &act, NULL);
+      }
+#else
+  for (i = 0; i < nsigs; i++)
+    if (signal (handled_sig[i], SIG_IGN) != SIG_IGN)
+      {
+        if (i == 0)
+          foreground = 1;
+        signal (handled_sig[i], abort_gzip_signal);
+        siginterrupt (handled_sig[i], 1);
+      }
+#endif
+}
+
+/* ========================================================================
+ * Free all dynamically allocated variables and exit with the given code.
+ */
+local void do_exit(exitcode)
+    int exitcode;
+{
+    static int in_exit = 0;
+
+    if (in_exit) exit(exitcode);
+    in_exit = 1;
+    free(env);
+    env  = NULL;
+    FREE(inbuf);
+    FREE(outbuf);
+    FREE(d_buf);
+    FREE(window);
+#ifndef MAXSEG_64K
+    FREE(tab_prefix);
+#else
+    FREE(tab_prefix0);
+    FREE(tab_prefix1);
+#endif
+    exit(exitcode);
+}
+
+static void
+finish_out (void)
+{
+  if (fclose (stdout) != 0)
+    write_error ();
+  do_exit (OK);
+}
+
+/* ========================================================================
+ * Close and unlink the output file.
+ */
+static void
+remove_output_file ()
+{
+  int fd;
+  sigset_t oldset;
+
+  sigprocmask (SIG_BLOCK, &caught_signals, &oldset);
+  fd = remove_ofname_fd;
+  if (0 <= fd)
+    {
+      remove_ofname_fd = -1;
+      close (fd);
+      xunlink (ofname);
+    }
+  sigprocmask (SIG_SETMASK, &oldset, NULL);
+}
+
+/* ========================================================================
+ * Error handler.
+ */
+void
+abort_gzip ()
+{
+   remove_output_file ();
+   do_exit(ERROR);
+}
+
+/* ========================================================================
+ * Signal handler.
+ */
+static RETSIGTYPE
+abort_gzip_signal (sig)
+     int sig;
+{
+  if (! SA_NOCLDSTOP)
+    signal (sig, SIG_IGN);
+   remove_output_file ();
+   if (sig == exiting_signal)
+     _exit (WARNING);
+   signal (sig, SIG_DFL);
+   raise (sig);
+}