root/usr.bin/gzip/gzip.c
/*      $NetBSD: gzip.c,v 1.116 2018/10/27 11:39:12 skrll Exp $ */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1997, 1998, 2003, 2004, 2006, 2008, 2009, 2010, 2011, 2015, 2017
 *    Matthew R. Green
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

/*
 * gzip.c -- GPL free gzip using zlib.
 *
 * RFC 1950 covers the zlib format
 * RFC 1951 covers the deflate format
 * RFC 1952 covers the gzip format
 *
 * TODO:
 *      - use mmap where possible
 *      - make bzip2/compress -v/-t/-l support work as well as possible
 */

#include <sys/endian.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <inttypes.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <zlib.h>
#include <fts.h>
#include <libgen.h>
#include <stdarg.h>
#include <getopt.h>
#include <time.h>

/* what type of file are we dealing with */
enum filetype {
        FT_GZIP,
#ifndef NO_BZIP2_SUPPORT
        FT_BZIP2,
#endif
#ifndef NO_COMPRESS_SUPPORT
        FT_Z,
#endif
#ifndef NO_PACK_SUPPORT
        FT_PACK,
#endif
#ifndef NO_XZ_SUPPORT
        FT_XZ,
#endif
#ifndef NO_LZ_SUPPORT
        FT_LZ,
#endif
#ifndef NO_ZSTD_SUPPORT
        FT_ZSTD,
#endif
        FT_LAST,
        FT_UNKNOWN
};

#ifndef NO_BZIP2_SUPPORT
#include <bzlib.h>

#define BZ2_SUFFIX      ".bz2"
#define BZIP2_MAGIC     "BZh"
#endif

#ifndef NO_COMPRESS_SUPPORT
#define Z_SUFFIX        ".Z"
#define Z_MAGIC         "\037\235"
#endif

#ifndef NO_PACK_SUPPORT
#define PACK_MAGIC      "\037\036"
#endif

#ifndef NO_XZ_SUPPORT
#include <lzma.h>
#define XZ_SUFFIX       ".xz"
#define XZ_MAGIC        "\3757zXZ"
#endif

#ifndef NO_LZ_SUPPORT
#define LZ_SUFFIX       ".lz"
#define LZ_MAGIC        "LZIP"
#endif

#ifndef NO_ZSTD_SUPPORT
#include <zstd.h>
#define ZSTD_SUFFIX     ".zst"
#define ZSTD_MAGIC      "\050\265\057\375"
#endif

#define GZ_SUFFIX       ".gz"

#define BUFLEN          (64 * 1024)

#define GZIP_MAGIC0     0x1F
#define GZIP_MAGIC1     0x8B
#define GZIP_OMAGIC1    0x9E

#define GZIP_TIMESTAMP  (off_t)4
#define GZIP_ORIGNAME   (off_t)10

#define HEAD_CRC        0x02
#define EXTRA_FIELD     0x04
#define ORIG_NAME       0x08
#define COMMENT         0x10

#define OS_CODE         3       /* Unix */

typedef struct {
    const char  *zipped;
    int         ziplen;
    const char  *normal;        /* for unzip - must not be longer than zipped */
} suffixes_t;
static suffixes_t suffixes[] = {
#define SUFFIX(Z, N) {Z, sizeof Z - 1, N}
        SUFFIX(GZ_SUFFIX,       ""),    /* Overwritten by -S .xxx */
        SUFFIX(GZ_SUFFIX,       ""),
        SUFFIX(".z",            ""),
        SUFFIX("-gz",           ""),
        SUFFIX("-z",            ""),
        SUFFIX("_z",            ""),
        SUFFIX(".taz",          ".tar"),
        SUFFIX(".tgz",          ".tar"),
#ifndef NO_BZIP2_SUPPORT
        SUFFIX(BZ2_SUFFIX,      ""),
        SUFFIX(".tbz",          ".tar"),
        SUFFIX(".tbz2",         ".tar"),
#endif
#ifndef NO_COMPRESS_SUPPORT
        SUFFIX(Z_SUFFIX,        ""),
#endif
#ifndef NO_XZ_SUPPORT
        SUFFIX(XZ_SUFFIX,       ""),
#endif
#ifndef NO_LZ_SUPPORT
        SUFFIX(LZ_SUFFIX,       ""),
#endif
#ifndef NO_ZSTD_SUPPORT
        SUFFIX(ZSTD_SUFFIX,     ""),
#endif
        SUFFIX(GZ_SUFFIX,       ""),    /* Overwritten by -S "" */
#undef SUFFIX
};
#define NUM_SUFFIXES (nitems(suffixes))
#define SUFFIX_MAXLEN   30

static  const char      gzip_version[] = "FreeBSD gzip 20190107";

static  const char      gzip_copyright[] = \
"   Copyright (c) 1997, 1998, 2003, 2004, 2006 Matthew R. Green\n"
"   All rights reserved.\n"
"\n"
"   Redistribution and use in source and binary forms, with or without\n"
"   modification, are permitted provided that the following conditions\n"
"   are met:\n"
"   1. Redistributions of source code must retain the above copyright\n"
"      notice, this list of conditions and the following disclaimer.\n"
"   2. Redistributions in binary form must reproduce the above copyright\n"
"      notice, this list of conditions and the following disclaimer in the\n"
"      documentation and/or other materials provided with the distribution.\n"
"\n"
"   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"
"   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\n"
"   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\n"
"   IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\n"
"   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,\n"
"   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;\n"
"   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED\n"
"   AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,\n"
"   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY\n"
"   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF\n"
"   SUCH DAMAGE.";

static  int     cflag;                  /* stdout mode */
static  int     dflag;                  /* decompress mode */
static  int     lflag;                  /* list mode */
static  int     numflag = 6;            /* gzip -1..-9 value */

static  const char *remove_file = NULL; /* file to be removed upon SIGINT */

static  int     fflag;                  /* force mode */
static  int     kflag;                  /* don't delete input files */
static  int     nflag;                  /* don't save name/timestamp */
static  int     Nflag;                  /* don't restore name/timestamp */
static  int     qflag;                  /* quiet mode */
static  int     rflag;                  /* recursive mode */
static  int     tflag;                  /* test */
static  int     vflag;                  /* verbose mode */
static  sig_atomic_t print_info = 0;

static  int     exit_value = 0;         /* exit value */

static  const char *infile;             /* name of file coming in */

static  void    maybe_err(const char *fmt, ...) __printflike(1, 2) __dead2;
#if !defined(NO_BZIP2_SUPPORT) || !defined(NO_PACK_SUPPORT) ||  \
    !defined(NO_XZ_SUPPORT) || !defined(NO_ZSTD_SUPPORT)
static  void    maybe_errx(const char *fmt, ...) __printflike(1, 2) __dead2;
#endif
static  void    maybe_warn(const char *fmt, ...) __printflike(1, 2);
static  void    maybe_warnx(const char *fmt, ...) __printflike(1, 2);
static  enum filetype file_gettype(u_char *);
static  off_t   gz_compress(int, int, off_t *, const char *, uint32_t);
static  off_t   gz_uncompress(int, int, char *, size_t, off_t *, const char *);
static  off_t   file_compress(char *, char *, size_t);
static  off_t   file_uncompress(char *, char *, size_t);
static  void    handle_pathname(char *);
static  void    handle_file(char *, struct stat *);
static  void    handle_stdin(void);
static  void    handle_stdout(void);
static  void    print_ratio(off_t, off_t, FILE *);
static  void    print_list(int fd, off_t, const char *, time_t);
static  void    usage(void) __dead2;
static  void    display_version(void) __dead2;
static  void    display_license(void);
static  const suffixes_t *check_suffix(char *, int);
static  ssize_t read_retry(int, void *, size_t);
static  ssize_t write_retry(int, const void *, size_t);
static void     print_list_out(off_t, off_t, const char*);

static  void    infile_set(const char *newinfile, off_t total);

static  off_t   infile_total;           /* total expected to read/write */
static  off_t   infile_current;         /* current read/write */

static  void    check_siginfo(void);
static  off_t   cat_fd(unsigned char *, size_t, off_t *, int fd);
static  void    prepend_gzip(char *, int *, char ***);
static  void    handle_dir(char *);
static  void    print_verbage(const char *, const char *, off_t, off_t);
static  void    print_test(const char *, int);
static  void    copymodes(int fd, const struct stat *, const char *file);
static  int     check_outfile(const char *outfile);
static  void    setup_signals(void);
static  void    infile_newdata(size_t newdata);
static  void    infile_clear(void);

#ifndef NO_BZIP2_SUPPORT
static  off_t   unbzip2(int, int, char *, size_t, off_t *);
#endif

#ifndef NO_COMPRESS_SUPPORT
static  FILE    *zdopen(int);
static  off_t   zuncompress(FILE *, FILE *, char *, size_t, off_t *);
#endif

#ifndef NO_PACK_SUPPORT
static  off_t   unpack(int, int, char *, size_t, off_t *);
#endif

#ifndef NO_XZ_SUPPORT
static  off_t   unxz(int, int, char *, size_t, off_t *);
static  off_t   unxz_len(int);
#endif

#ifndef NO_LZ_SUPPORT
static  off_t   unlz(int, int, char *, size_t, off_t *);
#endif

#ifndef NO_ZSTD_SUPPORT
static  off_t   unzstd(int, int, char *, size_t, off_t *);
#endif

static const struct option longopts[] = {
        { "stdout",             no_argument,            0,      'c' },
        { "to-stdout",          no_argument,            0,      'c' },
        { "decompress",         no_argument,            0,      'd' },
        { "uncompress",         no_argument,            0,      'd' },
        { "force",              no_argument,            0,      'f' },
        { "help",               no_argument,            0,      'h' },
        { "keep",               no_argument,            0,      'k' },
        { "list",               no_argument,            0,      'l' },
        { "no-name",            no_argument,            0,      'n' },
        { "name",               no_argument,            0,      'N' },
        { "quiet",              no_argument,            0,      'q' },
        { "recursive",          no_argument,            0,      'r' },
        { "suffix",             required_argument,      0,      'S' },
        { "test",               no_argument,            0,      't' },
        { "verbose",            no_argument,            0,      'v' },
        { "version",            no_argument,            0,      'V' },
        { "fast",               no_argument,            0,      '1' },
        { "best",               no_argument,            0,      '9' },
        { "ascii",              no_argument,            0,      'a' },
        { "license",            no_argument,            0,      'L' },
        { NULL,                 no_argument,            0,      0 },
};

int
main(int argc, char **argv)
{
        const char *progname = getprogname();
        char *gzip;
        int len;
        int ch;

        setup_signals();

        if ((gzip = getenv("GZIP")) != NULL)
                prepend_gzip(gzip, &argc, &argv);

        /*
         * XXX
         * handle being called `gunzip', `zcat' and `gzcat'
         */
        if (strcmp(progname, "gunzip") == 0)
                dflag = 1;
        else if (strcmp(progname, "zcat") == 0 ||
                 strcmp(progname, "gzcat") == 0)
                dflag = cflag = 1;

#define OPT_LIST "123456789acdfhklLNnqrS:tVv"

        while ((ch = getopt_long(argc, argv, OPT_LIST, longopts, NULL)) != -1) {
                switch (ch) {
                case '1': case '2': case '3':
                case '4': case '5': case '6':
                case '7': case '8': case '9':
                        numflag = ch - '0';
                        break;
                case 'c':
                        cflag = 1;
                        break;
                case 'd':
                        dflag = 1;
                        break;
                case 'l':
                        lflag = 1;
                        dflag = 1;
                        break;
                case 'V':
                        display_version();
                        /* NOTREACHED */
                case 'a':
                        fprintf(stderr, "%s: option --ascii ignored on this system\n", progname);
                        break;
                case 'f':
                        fflag = 1;
                        break;
                case 'k':
                        kflag = 1;
                        break;
                case 'L':
                        display_license();
                        /* NOT REACHED */
                case 'N':
                        nflag = 0;
                        Nflag = 1;
                        break;
                case 'n':
                        nflag = 1;
                        Nflag = 0;
                        break;
                case 'q':
                        qflag = 1;
                        break;
                case 'r':
                        rflag = 1;
                        break;
                case 'S':
                        len = strlen(optarg);
                        if (len != 0) {
                                if (len > SUFFIX_MAXLEN)
                                        errx(1, "incorrect suffix: '%s': too long", optarg);
                                suffixes[0].zipped = optarg;
                                suffixes[0].ziplen = len;
                        } else {
                                suffixes[NUM_SUFFIXES - 1].zipped = "";
                                suffixes[NUM_SUFFIXES - 1].ziplen = 0;
                        }
                        break;
                case 't':
                        cflag = 1;
                        tflag = 1;
                        dflag = 1;
                        break;
                case 'v':
                        vflag = 1;
                        break;
                default:
                        usage();
                        /* NOTREACHED */
                }
        }
        argv += optind;
        argc -= optind;

        if (argc == 0) {
                if (dflag)      /* stdin mode */
                        handle_stdin();
                else            /* stdout mode */
                        handle_stdout();
        } else {
                do {
                        handle_pathname(argv[0]);
                } while (*++argv);
        }
        if (qflag == 0 && lflag && argc > 1)
                print_list(-1, 0, "(totals)", 0);
        exit(exit_value);
}

/* maybe print a warning */
void
maybe_warn(const char *fmt, ...)
{
        va_list ap;

        if (qflag == 0) {
                va_start(ap, fmt);
                vwarn(fmt, ap);
                va_end(ap);
        }
        if (exit_value == 0)
                exit_value = 1;
}

/* ... without an errno. */
void
maybe_warnx(const char *fmt, ...)
{
        va_list ap;

        if (qflag == 0) {
                va_start(ap, fmt);
                vwarnx(fmt, ap);
                va_end(ap);
        }
        if (exit_value == 0)
                exit_value = 1;
}

/* maybe print an error */
void
maybe_err(const char *fmt, ...)
{
        va_list ap;

        if (qflag == 0) {
                va_start(ap, fmt);
                vwarn(fmt, ap);
                va_end(ap);
        }
        exit(2);
}

#if !defined(NO_BZIP2_SUPPORT) || !defined(NO_PACK_SUPPORT) ||  \
    !defined(NO_XZ_SUPPORT) || !defined(NO_ZSTD_SUPPORT)
/* ... without an errno. */
void
maybe_errx(const char *fmt, ...)
{
        va_list ap;

        if (qflag == 0) {
                va_start(ap, fmt);
                vwarnx(fmt, ap);
                va_end(ap);
        }
        exit(2);
}
#endif

/* split up $GZIP and prepend it to the argument list */
static void
prepend_gzip(char *gzip, int *argc, char ***argv)
{
        char *s, **nargv, **ac;
        int nenvarg = 0, i;

        /* scan how many arguments there are */
        for (s = gzip;;) {
                while (*s == ' ' || *s == '\t')
                        s++;
                if (*s == 0)
                        goto count_done;
                nenvarg++;
                while (*s != ' ' && *s != '\t')
                        if (*s++ == 0)
                                goto count_done;
        }
count_done:
        /* punt early */
        if (nenvarg == 0)
                return;

        *argc += nenvarg;
        ac = *argv;

        nargv = (char **)malloc((*argc + 1) * sizeof(char *));
        if (nargv == NULL)
                maybe_err("malloc");

        /* stash this away */
        *argv = nargv;

        /* copy the program name first */
        i = 0;
        nargv[i++] = *(ac++);

        /* take a copy of $GZIP and add it to the array */
        s = strdup(gzip);
        if (s == NULL)
                maybe_err("strdup");
        for (;;) {
                /* Skip whitespaces. */
                while (*s == ' ' || *s == '\t')
                        s++;
                if (*s == 0)
                        goto copy_done;
                nargv[i++] = s;
                /* Find the end of this argument. */
                while (*s != ' ' && *s != '\t')
                        if (*s++ == 0)
                                /* Argument followed by NUL. */
                                goto copy_done;
                /* Terminate by overwriting ' ' or '\t' with NUL. */
                *s++ = 0;
        }
copy_done:

        /* copy the original arguments and a NULL */
        while (*ac)
                nargv[i++] = *(ac++);
        nargv[i] = NULL;
}

/* compress input to output. Return bytes read, -1 on error */
static off_t
gz_compress(int in, int out, off_t *gsizep, const char *origname, uint32_t mtime)
{
        z_stream z;
        char *outbufp, *inbufp;
        off_t in_tot = 0, out_tot = 0;
        ssize_t in_size;
        int i, error;
        uLong crc;

        outbufp = malloc(BUFLEN);
        inbufp = malloc(BUFLEN);
        if (outbufp == NULL || inbufp == NULL) {
                maybe_err("malloc failed");
                goto out;
        }

        memset(&z, 0, sizeof z);
        z.zalloc = Z_NULL;
        z.zfree = Z_NULL;
        z.opaque = 0;

        if (nflag != 0) {
                mtime = 0;
                origname = "";
        }

        i = snprintf(outbufp, BUFLEN, "%c%c%c%c%c%c%c%c%c%c%s",
                     GZIP_MAGIC0, GZIP_MAGIC1, Z_DEFLATED,
                     *origname ? ORIG_NAME : 0,
                     mtime & 0xff,
                     (mtime >> 8) & 0xff,
                     (mtime >> 16) & 0xff,
                     (mtime >> 24) & 0xff,
                     numflag == 1 ? 4 : numflag == 9 ? 2 : 0,
                     OS_CODE, origname);
        if (i >= BUFLEN)
                /* this need PATH_MAX > BUFLEN ... */
                maybe_err("snprintf");
        if (*origname)
                i++;

        z.next_out = (unsigned char *)outbufp + i;
        z.avail_out = BUFLEN - i;

        error = deflateInit2(&z, numflag, Z_DEFLATED,
                             (-MAX_WBITS), 8, Z_DEFAULT_STRATEGY);
        if (error != Z_OK) {
                maybe_warnx("deflateInit2 failed");
                in_tot = -1;
                goto out;
        }

        crc = crc32(0L, Z_NULL, 0);
        for (;;) {
                if (z.avail_out == 0) {
                        if (write_retry(out, outbufp, BUFLEN) != BUFLEN) {
                                maybe_warn("write");
                                out_tot = -1;
                                goto out;
                        }

                        out_tot += BUFLEN;
                        z.next_out = (unsigned char *)outbufp;
                        z.avail_out = BUFLEN;
                }

                if (z.avail_in == 0) {
                        in_size = read(in, inbufp, BUFLEN);
                        if (in_size < 0) {
                                maybe_warn("read");
                                in_tot = -1;
                                goto out;
                        }
                        if (in_size == 0)
                                break;
                        infile_newdata(in_size);

                        crc = crc32(crc, (const Bytef *)inbufp, (unsigned)in_size);
                        in_tot += in_size;
                        z.next_in = (unsigned char *)inbufp;
                        z.avail_in = in_size;
                }

                error = deflate(&z, Z_NO_FLUSH);
                if (error != Z_OK && error != Z_STREAM_END) {
                        maybe_warnx("deflate failed");
                        in_tot = -1;
                        goto out;
                }
        }

        /* clean up */
        for (;;) {
                size_t len;
                ssize_t w;

                error = deflate(&z, Z_FINISH);
                if (error != Z_OK && error != Z_STREAM_END) {
                        maybe_warnx("deflate failed");
                        in_tot = -1;
                        goto out;
                }

                len = (char *)z.next_out - outbufp;

                w = write_retry(out, outbufp, len);
                if (w == -1 || (size_t)w != len) {
                        maybe_warn("write");
                        out_tot = -1;
                        goto out;
                }
                out_tot += len;
                z.next_out = (unsigned char *)outbufp;
                z.avail_out = BUFLEN;

                if (error == Z_STREAM_END)
                        break;
        }

        if (deflateEnd(&z) != Z_OK) {
                maybe_warnx("deflateEnd failed");
                in_tot = -1;
                goto out;
        }

        i = snprintf(outbufp, BUFLEN, "%c%c%c%c%c%c%c%c",
                 (int)crc & 0xff,
                 (int)(crc >> 8) & 0xff,
                 (int)(crc >> 16) & 0xff,
                 (int)(crc >> 24) & 0xff,
                 (int)in_tot & 0xff,
                 (int)(in_tot >> 8) & 0xff,
                 (int)(in_tot >> 16) & 0xff,
                 (int)(in_tot >> 24) & 0xff);
        if (i != 8)
                maybe_err("snprintf");
        if (write_retry(out, outbufp, i) != i) {
                maybe_warn("write");
                in_tot = -1;
        } else
                out_tot += i;

out:
        if (inbufp != NULL)
                free(inbufp);
        if (outbufp != NULL)
                free(outbufp);
        if (gsizep)
                *gsizep = out_tot;
        return in_tot;
}

/*
 * uncompress input to output then close the input.  return the
 * uncompressed size written, and put the compressed sized read
 * into `*gsizep'.
 */
static off_t
gz_uncompress(int in, int out, char *pre, size_t prelen, off_t *gsizep,
              const char *filename)
{
        z_stream z;
        char *outbufp, *inbufp;
        off_t out_tot = -1, in_tot = 0;
        uint32_t out_sub_tot = 0;
        enum {
                GZSTATE_MAGIC0,
                GZSTATE_MAGIC1,
                GZSTATE_METHOD,
                GZSTATE_FLAGS,
                GZSTATE_SKIPPING,
                GZSTATE_EXTRA,
                GZSTATE_EXTRA2,
                GZSTATE_EXTRA3,
                GZSTATE_ORIGNAME,
                GZSTATE_COMMENT,
                GZSTATE_HEAD_CRC1,
                GZSTATE_HEAD_CRC2,
                GZSTATE_INIT,
                GZSTATE_READ,
                GZSTATE_CRC,
                GZSTATE_LEN,
        } state = GZSTATE_MAGIC0;
        int flags = 0, skip_count = 0;
        int error = Z_STREAM_ERROR, done_reading = 0;
        uLong crc = 0;
        ssize_t wr;
        int needmore = 0;

#define ADVANCE()       { z.next_in++; z.avail_in--; }

        if ((outbufp = malloc(BUFLEN)) == NULL) {
                maybe_err("malloc failed");
                goto out2;
        }
        if ((inbufp = malloc(BUFLEN)) == NULL) {
                maybe_err("malloc failed");
                goto out1;
        }

        memset(&z, 0, sizeof z);
        z.avail_in = prelen;
        z.next_in = (unsigned char *)pre;
        z.avail_out = BUFLEN;
        z.next_out = (unsigned char *)outbufp;
        z.zalloc = NULL;
        z.zfree = NULL;
        z.opaque = 0;

        in_tot = prelen;
        out_tot = 0;

        for (;;) {
                check_siginfo();
                if ((z.avail_in == 0 || needmore) && done_reading == 0) {
                        ssize_t in_size;

                        if (z.avail_in > 0) {
                                memmove(inbufp, z.next_in, z.avail_in);
                        }
                        z.next_in = (unsigned char *)inbufp;
                        in_size = read(in, z.next_in + z.avail_in,
                            BUFLEN - z.avail_in);

                        if (in_size == -1) {
                                maybe_warn("failed to read stdin");
                                goto stop_and_fail;
                        } else if (in_size == 0) {
                                done_reading = 1;
                        }
                        infile_newdata(in_size);

                        z.avail_in += in_size;
                        needmore = 0;

                        in_tot += in_size;
                }
                if (z.avail_in == 0) {
                        if (done_reading && state != GZSTATE_MAGIC0) {
                                maybe_warnx("%s: unexpected end of file",
                                            filename);
                                goto stop_and_fail;
                        }
                        goto stop;
                }
                switch (state) {
                case GZSTATE_MAGIC0:
                        if (*z.next_in != GZIP_MAGIC0) {
                                if (in_tot > 0) {
                                        maybe_warnx("%s: trailing garbage "
                                                    "ignored", filename);
                                        exit_value = 2;
                                        goto stop;
                                }
                                maybe_warnx("input not gziped (MAGIC0)");
                                goto stop_and_fail;
                        }
                        ADVANCE();
                        state++;
                        out_sub_tot = 0;
                        crc = crc32(0L, Z_NULL, 0);
                        break;

                case GZSTATE_MAGIC1:
                        if (*z.next_in != GZIP_MAGIC1 &&
                            *z.next_in != GZIP_OMAGIC1) {
                                maybe_warnx("input not gziped (MAGIC1)");
                                goto stop_and_fail;
                        }
                        ADVANCE();
                        state++;
                        break;

                case GZSTATE_METHOD:
                        if (*z.next_in != Z_DEFLATED) {
                                maybe_warnx("unknown compression method");
                                goto stop_and_fail;
                        }
                        ADVANCE();
                        state++;
                        break;

                case GZSTATE_FLAGS:
                        flags = *z.next_in;
                        ADVANCE();
                        skip_count = 6;
                        state++;
                        break;

                case GZSTATE_SKIPPING:
                        if (skip_count > 0) {
                                skip_count--;
                                ADVANCE();
                        } else
                                state++;
                        break;

                case GZSTATE_EXTRA:
                        if ((flags & EXTRA_FIELD) == 0) {
                                state = GZSTATE_ORIGNAME;
                                break;
                        }
                        skip_count = *z.next_in;
                        ADVANCE();
                        state++;
                        break;

                case GZSTATE_EXTRA2:
                        skip_count |= ((*z.next_in) << 8);
                        ADVANCE();
                        state++;
                        break;

                case GZSTATE_EXTRA3:
                        if (skip_count > 0) {
                                skip_count--;
                                ADVANCE();
                        } else
                                state++;
                        break;

                case GZSTATE_ORIGNAME:
                        if ((flags & ORIG_NAME) == 0) {
                                state++;
                                break;
                        }
                        if (*z.next_in == 0)
                                state++;
                        ADVANCE();
                        break;

                case GZSTATE_COMMENT:
                        if ((flags & COMMENT) == 0) {
                                state++;
                                break;
                        }
                        if (*z.next_in == 0)
                                state++;
                        ADVANCE();
                        break;

                case GZSTATE_HEAD_CRC1:
                        if (flags & HEAD_CRC)
                                skip_count = 2;
                        else
                                skip_count = 0;
                        state++;
                        break;

                case GZSTATE_HEAD_CRC2:
                        if (skip_count > 0) {
                                skip_count--;
                                ADVANCE();
                        } else
                                state++;
                        break;

                case GZSTATE_INIT:
                        if (inflateInit2(&z, -MAX_WBITS) != Z_OK) {
                                maybe_warnx("failed to inflateInit");
                                goto stop_and_fail;
                        }
                        state++;
                        break;

                case GZSTATE_READ:
                        error = inflate(&z, Z_FINISH);
                        switch (error) {
                        /* Z_BUF_ERROR goes with Z_FINISH... */
                        case Z_BUF_ERROR:
                                if (z.avail_out > 0 && !done_reading)
                                        continue;

                        case Z_STREAM_END:
                        case Z_OK:
                                break;

                        case Z_NEED_DICT:
                                maybe_warnx("Z_NEED_DICT error");
                                goto stop_and_fail;
                        case Z_DATA_ERROR:
                                maybe_warnx("data stream error");
                                goto stop_and_fail;
                        case Z_STREAM_ERROR:
                                maybe_warnx("internal stream error");
                                goto stop_and_fail;
                        case Z_MEM_ERROR:
                                maybe_warnx("memory allocation error");
                                goto stop_and_fail;

                        default:
                                maybe_warn("unknown error from inflate(): %d",
                                    error);
                        }
                        wr = BUFLEN - z.avail_out;

                        if (wr != 0) {
                                crc = crc32(crc, (const Bytef *)outbufp, (unsigned)wr);
                                if (
                                    /* don't write anything with -t */
                                    tflag == 0 &&
                                    write_retry(out, outbufp, wr) != wr) {
                                        maybe_warn("error writing to output");
                                        goto stop_and_fail;
                                }

                                out_tot += wr;
                                out_sub_tot += wr;
                        }

                        if (error == Z_STREAM_END) {
                                inflateEnd(&z);
                                state++;
                        }

                        z.next_out = (unsigned char *)outbufp;
                        z.avail_out = BUFLEN;

                        break;
                case GZSTATE_CRC:
                        {
                                uLong origcrc;

                                if (z.avail_in < 4) {
                                        if (!done_reading) {
                                                needmore = 1;
                                                continue;
                                        }
                                        maybe_warnx("truncated input");
                                        goto stop_and_fail;
                                }
                                origcrc = le32dec(&z.next_in[0]);
                                if (origcrc != crc) {
                                        maybe_warnx("invalid compressed"
                                             " data--crc error");
                                        goto stop_and_fail;
                                }
                        }

                        z.avail_in -= 4;
                        z.next_in += 4;

                        if (!z.avail_in && done_reading) {
                                goto stop;
                        }
                        state++;
                        break;
                case GZSTATE_LEN:
                        {
                                uLong origlen;

                                if (z.avail_in < 4) {
                                        if (!done_reading) {
                                                needmore = 1;
                                                continue;
                                        }
                                        maybe_warnx("truncated input");
                                        goto stop_and_fail;
                                }
                                origlen = le32dec(&z.next_in[0]);

                                if (origlen != out_sub_tot) {
                                        maybe_warnx("invalid compressed"
                                             " data--length error");
                                        goto stop_and_fail;
                                }
                        }
                                
                        z.avail_in -= 4;
                        z.next_in += 4;

                        if (error < 0) {
                                maybe_warnx("decompression error");
                                goto stop_and_fail;
                        }
                        state = GZSTATE_MAGIC0;
                        break;
                }
                continue;
stop_and_fail:
                out_tot = -1;
stop:
                break;
        }
        if (state > GZSTATE_INIT)
                inflateEnd(&z);

        free(inbufp);
out1:
        free(outbufp);
out2:
        if (gsizep)
                *gsizep = in_tot;
        return (out_tot);
}

/*
 * set the owner, mode, flags & utimes using the given file descriptor.
 * file is only used in possible warning messages.
 */
static void
copymodes(int fd, const struct stat *sbp, const char *file)
{
        struct timespec times[2];
        struct stat sb;

        /*
         * If we have no info on the input, give this file some
         * default values and return..
         */
        if (sbp == NULL) {
                mode_t mask = umask(022);

                (void)fchmod(fd, DEFFILEMODE & ~mask);
                (void)umask(mask);
                return;
        }
        sb = *sbp;

        /* if the chown fails, remove set-id bits as-per compress(1) */
        if (fchown(fd, sb.st_uid, sb.st_gid) < 0) {
                if (errno != EPERM)
                        maybe_warn("couldn't fchown: %s", file);
                sb.st_mode &= ~(S_ISUID|S_ISGID);
        }

        /* we only allow set-id and the 9 normal permission bits */
        sb.st_mode &= S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;
        if (fchmod(fd, sb.st_mode) < 0)
                maybe_warn("couldn't fchmod: %s", file);

        times[0] = sb.st_atim;
        times[1] = sb.st_mtim;
        if (futimens(fd, times) < 0)
                maybe_warn("couldn't futimens: %s", file);

        /* only try flags if they exist already */
        if (sb.st_flags != 0 && fchflags(fd, sb.st_flags) < 0)
                maybe_warn("couldn't fchflags: %s", file);
}

/* what sort of file is this? */
static enum filetype
file_gettype(u_char *buf)
{

        if (buf[0] == GZIP_MAGIC0 &&
            (buf[1] == GZIP_MAGIC1 || buf[1] == GZIP_OMAGIC1))
                return FT_GZIP;
#ifndef NO_BZIP2_SUPPORT
        else if (memcmp(buf, BZIP2_MAGIC, 3) == 0 &&
            buf[3] >= '0' && buf[3] <= '9')
                return FT_BZIP2;
#endif
#ifndef NO_COMPRESS_SUPPORT
        else if (memcmp(buf, Z_MAGIC, 2) == 0)
                return FT_Z;
#endif
#ifndef NO_PACK_SUPPORT
        else if (memcmp(buf, PACK_MAGIC, 2) == 0)
                return FT_PACK;
#endif
#ifndef NO_XZ_SUPPORT
        else if (memcmp(buf, XZ_MAGIC, 4) == 0) /* XXX: We only have 4 bytes */
                return FT_XZ;
#endif
#ifndef NO_LZ_SUPPORT
        else if (memcmp(buf, LZ_MAGIC, 4) == 0)
                return FT_LZ;
#endif
#ifndef NO_ZSTD_SUPPORT
        else if (memcmp(buf, ZSTD_MAGIC, 4) == 0)
                return FT_ZSTD;
#endif
        else
                return FT_UNKNOWN;
}

/* check the outfile is OK. */
static int
check_outfile(const char *outfile)
{
        struct stat sb;
        int ok = 1;

        if (lflag == 0 && stat(outfile, &sb) == 0) {
                if (fflag)
                        unlink(outfile);
                else if (isatty(STDIN_FILENO)) {
                        char ans[10] = { 'n', '\0' };   /* default */

                        fprintf(stderr, "%s already exists -- do you wish to "
                                        "overwrite (y or n)? " , outfile);
                        (void)fgets(ans, sizeof(ans) - 1, stdin);
                        if (ans[0] != 'y' && ans[0] != 'Y') {
                                fprintf(stderr, "\tnot overwriting\n");
                                ok = 0;
                        } else
                                unlink(outfile);
                } else {
                        maybe_warnx("%s already exists -- skipping", outfile);
                        ok = 0;
                }
        }
        return ok;
}

static void
unlink_input(const char *file, const struct stat *sb)
{
        struct stat nsb;

        if (kflag)
                return;
        if (stat(file, &nsb) != 0)
                /* Must be gone already */
                return;
        if (nsb.st_dev != sb->st_dev || nsb.st_ino != sb->st_ino)
                /* Definitely a different file */
                return;
        unlink(file);
}

static void
got_sigint(int signo __unused)
{

        if (remove_file != NULL)
                unlink(remove_file);
        _exit(2);
}

static void
got_siginfo(int signo __unused)
{

        print_info = 1;
}

static void
setup_signals(void)
{

        signal(SIGINFO, got_siginfo);
        signal(SIGINT, got_sigint);
}

static  void
infile_newdata(size_t newdata)
{

        infile_current += newdata;
}

static  void
infile_set(const char *newinfile, off_t total)
{

        if (newinfile)
                infile = newinfile;
        infile_total = total;
}

static  void
infile_clear(void)
{

        infile = NULL;
        infile_total = infile_current = 0;
}

static const suffixes_t *
check_suffix(char *file, int xlate)
{
        const suffixes_t *s;
        int len = strlen(file);
        char *sp;

        for (s = suffixes; s != suffixes + NUM_SUFFIXES; s++) {
                /* if it doesn't fit in "a.suf", don't bother */
                if (s->ziplen >= len)
                        continue;
                sp = file + len - s->ziplen;
                if (strcmp(s->zipped, sp) != 0)
                        continue;
                if (xlate)
                        strcpy(sp, s->normal);
                return s;
        }
        return NULL;
}

/*
 * compress the given file: create a corresponding .gz file and remove the
 * original.
 */
static off_t
file_compress(char *file, char *outfile, size_t outsize)
{
        int in;
        int out;
        off_t size, in_size;
        struct stat isb, osb;
        const suffixes_t *suff;

        in = open(file, O_RDONLY);
        if (in == -1) {
                maybe_warn("can't open %s", file);
                return (-1);
        }

        if (fstat(in, &isb) != 0) {
                maybe_warn("couldn't stat: %s", file);
                close(in);
                return (-1);
        }

        if (fstat(in, &isb) != 0) {
                close(in);
                maybe_warn("can't stat %s", file);
                return -1;
        }
        infile_set(file, isb.st_size);

        if (cflag == 0) {
                if (isb.st_nlink > 1 && fflag == 0) {
                        maybe_warnx("%s has %ju other link%s -- "
                                    "skipping", file,
                                    (uintmax_t)isb.st_nlink - 1,
                                    isb.st_nlink == 1 ? "" : "s");
                        close(in);
                        return -1;
                }

                if (fflag == 0 && (suff = check_suffix(file, 0)) &&
                    suff->zipped[0] != 0) {
                        maybe_warnx("%s already has %s suffix -- unchanged",
                            file, suff->zipped);
                        close(in);
                        return (-1);
                }

                /* Add (usually) .gz to filename */
                if ((size_t)snprintf(outfile, outsize, "%s%s",
                    file, suffixes[0].zipped) >= outsize)
                        memcpy(outfile + outsize - suffixes[0].ziplen - 1,
                            suffixes[0].zipped, suffixes[0].ziplen + 1);

                if (check_outfile(outfile) == 0) {
                        close(in);
                        return (-1);
                }
        }

        if (cflag == 0) {
                out = open(outfile, O_WRONLY | O_CREAT | O_EXCL, 0600);
                if (out == -1) {
                        maybe_warn("could not create output: %s", outfile);
                        fclose(stdin);
                        return (-1);
                }
                remove_file = outfile;
        } else
                out = STDOUT_FILENO;

        in_size = gz_compress(in, out, &size, basename(file), (uint32_t)isb.st_mtime);

        (void)close(in);

        /*
         * If there was an error, in_size will be -1.
         * If we compressed to stdout, just return the size.
         * Otherwise stat the file and check it is the correct size.
         * We only blow away the file if we can stat the output and it
         * has the expected size.
         */
        if (cflag != 0)
                return in_size == -1 ? -1 : size;

        if (fstat(out, &osb) != 0) {
                maybe_warn("couldn't stat: %s", outfile);
                goto bad_outfile;
        }

        if (osb.st_size != size) {
                maybe_warnx("output file: %s wrong size (%ju != %ju), deleting",
                    outfile, (uintmax_t)osb.st_size, (uintmax_t)size);
                goto bad_outfile;
        }

        copymodes(out, &isb, outfile);
        remove_file = NULL;
        if (close(out) == -1)
                maybe_warn("couldn't close output");

        /* output is good, ok to delete input */
        unlink_input(file, &isb);
        return (size);

    bad_outfile:
        if (close(out) == -1)
                maybe_warn("couldn't close output");

        maybe_warnx("leaving original %s", file);
        unlink(outfile);
        return (size);
}

/* uncompress the given file and remove the original */
static off_t
file_uncompress(char *file, char *outfile, size_t outsize)
{
        struct stat isb, osb;
        off_t size;
        ssize_t rbytes;
        unsigned char fourbytes[4];
        enum filetype method;
        int fd, ofd, zfd = -1;
        int error;
        size_t in_size;
        ssize_t rv;
        time_t timestamp = 0;
        char name[PATH_MAX + 1];

        /* gather the old name info */

        fd = open(file, O_RDONLY);
        if (fd < 0) {
                maybe_warn("can't open %s", file);
                goto lose;
        }
        if (fstat(fd, &isb) != 0) {
                maybe_warn("can't stat %s", file);
                goto lose;
        }
        if (S_ISREG(isb.st_mode))
                in_size = isb.st_size;
        else
                in_size = 0;
        infile_set(file, in_size);

        strlcpy(outfile, file, outsize);
        if (check_suffix(outfile, 1) == NULL && !(cflag || lflag)) {
                maybe_warnx("%s: unknown suffix -- ignored", file);
                goto lose;
        }

        rbytes = read(fd, fourbytes, sizeof fourbytes);
        if (rbytes != sizeof fourbytes) {
                /* we don't want to fail here. */
                if (fflag)
                        goto lose;
                if (rbytes == -1)
                        maybe_warn("can't read %s", file);
                else
                        goto unexpected_EOF;
                goto lose;
        }
        infile_newdata(rbytes);

        method = file_gettype(fourbytes);
        if (fflag == 0 && method == FT_UNKNOWN) {
                maybe_warnx("%s: not in gzip format", file);
                goto lose;
        }


        if (method == FT_GZIP && Nflag) {
                unsigned char ts[4];    /* timestamp */

                rv = pread(fd, ts, sizeof ts, GZIP_TIMESTAMP);
                if (rv >= 0 && rv < (ssize_t)(sizeof ts))
                        goto unexpected_EOF;
                if (rv == -1) {
                        if (!fflag)
                                maybe_warn("can't read %s", file);
                        goto lose;
                }
                infile_newdata(rv);
                timestamp = le32dec(&ts[0]);

                if (fourbytes[3] & ORIG_NAME) {
                        rbytes = pread(fd, name, sizeof(name) - 1, GZIP_ORIGNAME);
                        if (rbytes < 0) {
                                maybe_warn("can't read %s", file);
                                goto lose;
                        }
                        if (name[0] != '\0') {
                                char *dp, *nf;

                                /* Make sure that name is NUL-terminated */
                                name[rbytes] = '\0';

                                /* strip saved directory name */
                                nf = strrchr(name, '/');
                                if (nf == NULL)
                                        nf = name;
                                else
                                        nf++;

                                /* preserve original directory name */
                                dp = strrchr(file, '/');
                                if (dp == NULL)
                                        dp = file;
                                else
                                        dp++;
                                snprintf(outfile, outsize, "%.*s%.*s",
                                                (int) (dp - file),
                                                file, (int) rbytes, nf);
                        }
                }
        }
        lseek(fd, 0, SEEK_SET);

        if (cflag == 0 || lflag) {
                if (isb.st_nlink > 1 && lflag == 0 && fflag == 0) {
                        maybe_warnx("%s has %ju other links -- skipping",
                            file, (uintmax_t)isb.st_nlink - 1);
                        goto lose;
                }
                if (nflag == 0 && timestamp)
                        isb.st_mtime = timestamp;
                if (check_outfile(outfile) == 0)
                        goto lose;
        }

        if (cflag)
                zfd = STDOUT_FILENO;
        else if (lflag)
                zfd = -1;
        else {
                zfd = open(outfile, O_WRONLY|O_CREAT|O_EXCL, 0600);
                if (zfd == STDOUT_FILENO) {
                        /* We won't close STDOUT_FILENO later... */
                        zfd = dup(zfd);
                        close(STDOUT_FILENO);
                }
                if (zfd == -1) {
                        maybe_warn("can't open %s", outfile);
                        goto lose;
                }
                remove_file = outfile;
        }

        switch (method) {
#ifndef NO_BZIP2_SUPPORT
        case FT_BZIP2:
                /* XXX */
                if (lflag) {
                        maybe_warnx("no -l with bzip2 files");
                        goto lose;
                }

                size = unbzip2(fd, zfd, NULL, 0, NULL);
                break;
#endif

#ifndef NO_COMPRESS_SUPPORT
        case FT_Z: {
                FILE *in, *out;

                /* XXX */
                if (lflag) {
                        maybe_warnx("no -l with Lempel-Ziv files");
                        goto lose;
                }

                if ((in = zdopen(fd)) == NULL) {
                        maybe_warn("zdopen for read: %s", file);
                        goto lose;
                }

                out = fdopen(dup(zfd), "w");
                if (out == NULL) {
                        maybe_warn("fdopen for write: %s", outfile);
                        fclose(in);
                        goto lose;
                }

                size = zuncompress(in, out, NULL, 0, NULL);
                /* need to fclose() if ferror() is true... */
                error = ferror(in);
                if (error | fclose(in)) {
                        if (error)
                                maybe_warn("failed infile");
                        else
                                maybe_warn("failed infile fclose");
                        if (cflag == 0)
                                unlink(outfile);
                        (void)fclose(out);
                        goto lose;
                }
                if (fclose(out) != 0) {
                        maybe_warn("failed outfile fclose");
                        if (cflag == 0)
                                unlink(outfile);
                        goto lose;
                }
                break;
        }
#endif

#ifndef NO_PACK_SUPPORT
        case FT_PACK:
                if (lflag) {
                        maybe_warnx("no -l with packed files");
                        goto lose;
                }

                size = unpack(fd, zfd, NULL, 0, NULL);
                break;
#endif

#ifndef NO_XZ_SUPPORT
        case FT_XZ:
                if (lflag) {
                        size = unxz_len(fd);
                        if (!tflag) {
                                print_list_out(in_size, size, file);
                                close(fd);
                                return -1;
                        }
                } else
                        size = unxz(fd, zfd, NULL, 0, NULL);
                break;
#endif

#ifndef NO_LZ_SUPPORT
        case FT_LZ:
                if (lflag) {
                        maybe_warnx("no -l with lzip files");
                        goto lose;
                }
                size = unlz(fd, zfd, NULL, 0, NULL);
                break;
#endif

#ifndef NO_ZSTD_SUPPORT
        case FT_ZSTD:
                if (lflag) {
                        maybe_warnx("no -l with zstd files");
                        goto lose;
                }
                size = unzstd(fd, zfd, NULL, 0, NULL);
                break;
#endif
        case FT_UNKNOWN:
                if (lflag) {
                        maybe_warnx("no -l for unknown filetypes");
                        goto lose;
                }
                size = cat_fd(NULL, 0, NULL, fd);
                break;
        default:
                if (lflag) {
                        print_list(fd, in_size, outfile, isb.st_mtime);
                        if (!tflag) {
                                close(fd);
                                return -1;      /* XXX */
                        }
                }

                size = gz_uncompress(fd, zfd, NULL, 0, NULL, file);
                break;
        }

        if (close(fd) != 0)
                maybe_warn("couldn't close input");
        if (zfd != STDOUT_FILENO && close(zfd) != 0)
                maybe_warn("couldn't close output");

        if (size == -1) {
                if (cflag == 0)
                        unlink(outfile);
                maybe_warnx("%s: uncompress failed", file);
                return -1;
        }

        /* if testing, or we uncompressed to stdout, this is all we need */
        if (tflag)
                return size;
        /* if we are uncompressing to stdin, don't remove the file. */
        if (cflag)
                return size;

        /*
         * if we create a file...
         */
        /*
         * if we can't stat the file don't remove the file.
         */

        ofd = open(outfile, O_RDWR, 0);
        if (ofd == -1) {
                maybe_warn("couldn't open (leaving original): %s",
                           outfile);
                return -1;
        }
        if (fstat(ofd, &osb) != 0) {
                maybe_warn("couldn't stat (leaving original): %s",
                           outfile);
                close(ofd);
                return -1;
        }
        if (osb.st_size != size) {
                maybe_warnx("stat gave different size: %ju != %ju (leaving original)",
                    (uintmax_t)size, (uintmax_t)osb.st_size);
                close(ofd);
                unlink(outfile);
                return -1;
        }
        copymodes(ofd, &isb, outfile);
        remove_file = NULL;
        close(ofd);
        unlink_input(file, &isb);
        return size;

    unexpected_EOF:
        maybe_warnx("%s: unexpected end of file", file);
    lose:
        if (fd != -1)
                close(fd);
        if (zfd != -1 && zfd != STDOUT_FILENO)
                close(zfd);
        return -1;
}

static void
check_siginfo(void)
{
        if (print_info == 0)
                return;
        if (infile) {
                if (infile_total) {
                        int pcent = (int)((100.0 * infile_current) / infile_total);

                        fprintf(stderr, "%s: done %llu/%llu bytes %d%%\n",
                                infile, (unsigned long long)infile_current,
                                (unsigned long long)infile_total, pcent);
                } else
                        fprintf(stderr, "%s: done %llu bytes\n",
                                infile, (unsigned long long)infile_current);
        }
        print_info = 0;
}

static off_t
cat_fd(unsigned char * prepend, size_t count, off_t *gsizep, int fd)
{
        char buf[BUFLEN];
        off_t in_tot;
        ssize_t w;

        in_tot = count;
        w = write_retry(STDOUT_FILENO, prepend, count);
        if (w == -1 || (size_t)w != count) {
                maybe_warn("write to stdout");
                return -1;
        }
        for (;;) {
                ssize_t rv;

                rv = read(fd, buf, sizeof buf);
                if (rv == 0)
                        break;
                if (rv < 0) {
                        maybe_warn("read from fd %d", fd);
                        break;
                }
                infile_newdata(rv);

                if (write_retry(STDOUT_FILENO, buf, rv) != rv) {
                        maybe_warn("write to stdout");
                        break;
                }
                in_tot += rv;
        }

        if (gsizep)
                *gsizep = in_tot;
        return (in_tot);
}

static void
handle_stdin(void)
{
        struct stat isb;
        unsigned char fourbytes[4];
        size_t in_size;
        off_t usize, gsize;
        enum filetype method;
        ssize_t bytes_read;
#ifndef NO_COMPRESS_SUPPORT
        FILE *in;
#endif

        if (fflag == 0 && lflag == 0 && isatty(STDIN_FILENO)) {
                maybe_warnx("standard input is a terminal -- ignoring");
                goto out;
        }

        if (fstat(STDIN_FILENO, &isb) < 0) {
                maybe_warn("fstat");
                goto out;
        }
        if (S_ISREG(isb.st_mode))
                in_size = isb.st_size;
        else
                in_size = 0;
        infile_set("(stdin)", in_size);

        if (lflag) {
                print_list(STDIN_FILENO, in_size, infile, isb.st_mtime);
                goto out;
        }

        bytes_read = read_retry(STDIN_FILENO, fourbytes, sizeof fourbytes);
        if (bytes_read == -1) {
                maybe_warn("can't read stdin");
                goto out;
        } else if (bytes_read != sizeof(fourbytes)) {
                maybe_warnx("(stdin): unexpected end of file");
                goto out;
        }

        method = file_gettype(fourbytes);
        switch (method) {
        default:
                if (fflag == 0) {
                        maybe_warnx("unknown compression format");
                        goto out;
                }
                usize = cat_fd(fourbytes, sizeof fourbytes, &gsize, STDIN_FILENO);
                break;
        case FT_GZIP:
                usize = gz_uncompress(STDIN_FILENO, STDOUT_FILENO,
                              (char *)fourbytes, sizeof fourbytes, &gsize, "(stdin)");
                break;
#ifndef NO_BZIP2_SUPPORT
        case FT_BZIP2:
                usize = unbzip2(STDIN_FILENO, STDOUT_FILENO,
                                (char *)fourbytes, sizeof fourbytes, &gsize);
                break;
#endif
#ifndef NO_COMPRESS_SUPPORT
        case FT_Z:
                if ((in = zdopen(STDIN_FILENO)) == NULL) {
                        maybe_warnx("zopen of stdin");
                        goto out;
                }

                usize = zuncompress(in, stdout, (char *)fourbytes,
                    sizeof fourbytes, &gsize);
                fclose(in);
                break;
#endif
#ifndef NO_PACK_SUPPORT
        case FT_PACK:
                usize = unpack(STDIN_FILENO, STDOUT_FILENO,
                               (char *)fourbytes, sizeof fourbytes, &gsize);
                break;
#endif
#ifndef NO_XZ_SUPPORT
        case FT_XZ:
                usize = unxz(STDIN_FILENO, STDOUT_FILENO,
                             (char *)fourbytes, sizeof fourbytes, &gsize);
                break;
#endif
#ifndef NO_LZ_SUPPORT
        case FT_LZ:
                usize = unlz(STDIN_FILENO, STDOUT_FILENO,
                             (char *)fourbytes, sizeof fourbytes, &gsize);
                break;
#endif
#ifndef NO_ZSTD_SUPPORT
        case FT_ZSTD:
                usize = unzstd(STDIN_FILENO, STDOUT_FILENO,
                               (char *)fourbytes, sizeof fourbytes, &gsize);
                break;
#endif
        }

        if (vflag && !tflag && usize != -1 && gsize != -1)
                print_verbage(NULL, NULL, usize, gsize);
        if (vflag && tflag)
                print_test("(stdin)", usize != -1);

out:
        infile_clear();
}

static void
handle_stdout(void)
{
        off_t gsize;
        off_t usize;
        struct stat sb;
        time_t systime;
        uint32_t mtime;
        int ret;

        infile_set("(stdout)", 0);

        if (fflag == 0 && isatty(STDOUT_FILENO)) {
                maybe_warnx("standard output is a terminal -- ignoring");
                return;
        }

        /* If stdin is a file use its mtime, otherwise use current time */
        ret = fstat(STDIN_FILENO, &sb);
        if (ret < 0) {
                maybe_warn("Can't stat stdin");
                return;
        }

        if (S_ISREG(sb.st_mode)) {
                infile_set("(stdout)", sb.st_size);
                mtime = (uint32_t)sb.st_mtime;
        } else {
                systime = time(NULL);
                if (systime == -1) {
                        maybe_warn("time");
                        return;
                }
                mtime = (uint32_t)systime;
        }
                        
        usize =
                gz_compress(STDIN_FILENO, STDOUT_FILENO, &gsize, "", mtime);
        if (vflag && !tflag && usize != -1 && gsize != -1)
                print_verbage(NULL, NULL, usize, gsize);
}

/* do what is asked for, for the path name */
static void
handle_pathname(char *path)
{
        char *opath = path, *s = NULL;
        ssize_t len;
        int slen;
        struct stat sb;

        /* check for stdout/stdin */
        if (path[0] == '-' && path[1] == '\0') {
                if (dflag)
                        handle_stdin();
                else
                        handle_stdout();
                return;
        }

retry:
        if (stat(path, &sb) != 0 || (fflag == 0 && cflag == 0 &&
            lstat(path, &sb) != 0)) {
                /* lets try <path>.gz if we're decompressing */
                if (dflag && s == NULL && errno == ENOENT) {
                        len = strlen(path);
                        slen = suffixes[0].ziplen;
                        s = malloc(len + slen + 1);
                        if (s == NULL)
                                maybe_err("malloc");
                        memcpy(s, path, len);
                        memcpy(s + len, suffixes[0].zipped, slen + 1);
                        path = s;
                        goto retry;
                }
                maybe_warn("can't stat: %s", opath);
                goto out;
        }

        if (S_ISDIR(sb.st_mode)) {
                if (rflag)
                        handle_dir(path);
                else
                        maybe_warnx("%s is a directory", path);
                goto out;
        }

        if (S_ISREG(sb.st_mode))
                handle_file(path, &sb);
        else
                maybe_warnx("%s is not a regular file", path);

out:
        if (s)
                free(s);
}

/* compress/decompress a file */
static void
handle_file(char *file, struct stat *sbp)
{
        off_t usize, gsize;
        char    outfile[PATH_MAX];

        infile_set(file, sbp->st_size);
        if (dflag) {
                usize = file_uncompress(file, outfile, sizeof(outfile));
                if (vflag && tflag)
                        print_test(file, usize != -1);
                if (usize == -1)
                        return;
                gsize = sbp->st_size;
        } else {
                gsize = file_compress(file, outfile, sizeof(outfile));
                if (gsize == -1)
                        return;
                usize = sbp->st_size;
        }
        infile_clear();

        if (vflag && !tflag)
                print_verbage(file, (cflag) ? NULL : outfile, usize, gsize);
}

/* this is used with -r to recursively descend directories */
static void
handle_dir(char *dir)
{
        char *path_argv[2];
        FTS *fts;
        FTSENT *entry;

        path_argv[0] = dir;
        path_argv[1] = 0;
        fts = fts_open(path_argv, FTS_PHYSICAL | FTS_NOCHDIR, NULL);
        if (fts == NULL) {
                warn("couldn't fts_open %s", dir);
                return;
        }

        while (errno = 0, (entry = fts_read(fts))) {
                switch(entry->fts_info) {
                case FTS_D:
                case FTS_DP:
                        continue;

                case FTS_DNR:
                case FTS_ERR:
                case FTS_NS:
                        maybe_warn("%s", entry->fts_path);
                        continue;
                case FTS_F:
                        handle_file(entry->fts_path, entry->fts_statp);
                }
        }
        if (errno != 0)
                warn("error with fts_read %s", dir);
        (void)fts_close(fts);
}

/* print a ratio - size reduction as a fraction of uncompressed size */
static void
print_ratio(off_t in, off_t out, FILE *where)
{
        int percent10;  /* 10 * percent */
        off_t diff;
        char buff[8];
        int len;

        diff = in - out/2;
        if (in == 0 && out == 0)
                percent10 = 0;
        else if (diff < 0)
                /*
                 * Output is more than double size of input! print -99.9%
                 * Quite possibly we've failed to get the original size.
                 */
                percent10 = -999;
        else {
                /*
                 * We only need 12 bits of result from the final division,
                 * so reduce the values until a 32bit division will suffice.
                 */
                while (in > 0x100000) {
                        diff >>= 1;
                        in >>= 1;
                }
                if (in != 0)
                        percent10 = ((u_int)diff * 2000) / (u_int)in - 1000;
                else
                        percent10 = 0;
        }

        len = snprintf(buff, sizeof buff, "%2.2d.", percent10);
        /* Move the '.' to before the last digit */
        buff[len - 1] = buff[len - 2];
        buff[len - 2] = '.';
        fprintf(where, "%5s%%", buff);
}

/* print compression statistics, and the new name (if there is one!) */
static void
print_verbage(const char *file, const char *nfile, off_t usize, off_t gsize)
{
        if (file)
                fprintf(stderr, "%s:%s  ", file,
                    strlen(file) < 7 ? "\t\t" : "\t");
        print_ratio(usize, gsize, stderr);
        if (nfile)
                fprintf(stderr, " -- replaced with %s", nfile);
        fprintf(stderr, "\n");
        fflush(stderr);
}

/* print test results */
static void
print_test(const char *file, int ok)
{

        if (exit_value == 0 && ok == 0)
                exit_value = 1;
        fprintf(stderr, "%s:%s  %s\n", file,
            strlen(file) < 7 ? "\t\t" : "\t", ok ? "OK" : "NOT OK");
        fflush(stderr);
}

/* print a file's info ala --list */
/* eg:
  compressed uncompressed  ratio uncompressed_name
      354841      1679360  78.8% /usr/pkgsrc/distfiles/libglade-2.0.1.tar
*/
static void
print_list(int fd, off_t out, const char *outfile, time_t ts)
{
        static int first = 1;
        static off_t in_tot, out_tot;
        uint32_t crc = 0;
        off_t in = 0, rv;

        if (first) {
                if (vflag)
                        printf("method  crc     date  time  ");
                if (qflag == 0)
                        printf("  compressed uncompressed  "
                               "ratio uncompressed_name\n");
        }
        first = 0;

        /* print totals? */
        if (fd == -1) {
                in = in_tot;
                out = out_tot;
        } else
        {
                /* read the last 4 bytes - this is the uncompressed size */
                rv = lseek(fd, (off_t)(-8), SEEK_END);
                if (rv != -1) {
                        unsigned char buf[8];
                        uint32_t usize;

                        rv = read(fd, (char *)buf, sizeof(buf));
                        if (rv == -1)
                                maybe_warn("read of uncompressed size");
                        else if (rv != sizeof(buf))
                                maybe_warnx("read of uncompressed size");

                        else {
                                usize = le32dec(&buf[4]);
                                in = (off_t)usize;
                                crc = le32dec(&buf[0]);
                        }
                }
        }

        if (vflag && fd == -1)
                printf("                            ");
        else if (vflag) {
                char *date = ctime(&ts);

                /* skip the day, 1/100th second, and year */
                date += 4;
                date[12] = 0;
                printf("%5s %08x %11s ", "defla"/*XXX*/, crc, date);
        }
        in_tot += in;
        out_tot += out;
        print_list_out(out, in, outfile);
}

static void
print_list_out(off_t out, off_t in, const char *outfile)
{
        printf("%12llu %12llu ", (unsigned long long)out, (unsigned long long)in);
        print_ratio(in, out, stdout);
        printf(" %s\n", outfile);
}

/* display the usage of NetBSD gzip */
static void
usage(void)
{

        fprintf(stderr, "%s\n", gzip_version);
        fprintf(stderr,
    "usage: %s [-123456789acdfhklLNnqrtVv] [-S .suffix] [<file> [<file> ...]]\n"
    " -1 --fast            fastest (worst) compression\n"
    " -2 .. -8             set compression level\n"
    " -9 --best            best (slowest) compression\n"
    " -c --stdout          write to stdout, keep original files\n"
    "    --to-stdout\n"
    " -d --decompress      uncompress files\n"
    "    --uncompress\n"
    " -f --force           force overwriting & compress links\n"
    " -h --help            display this help\n"
    " -k --keep            don't delete input files during operation\n"
    " -l --list            list compressed file contents\n"
    " -N --name            save or restore original file name and time stamp\n"
    " -n --no-name         don't save original file name or time stamp\n"
    " -q --quiet           output no warnings\n"
    " -r --recursive       recursively compress files in directories\n"
    " -S .suf              use suffix .suf instead of .gz\n"
    "    --suffix .suf\n"
    " -t --test            test compressed file\n"
    " -V --version         display program version\n"
    " -v --verbose         print extra statistics\n",
            getprogname());
        exit(0);
}

/* display the license information of FreeBSD gzip */
static void
display_license(void)
{

        fprintf(stderr, "%s (based on NetBSD gzip 20150113)\n", gzip_version);
        fprintf(stderr, "%s\n", gzip_copyright);
        exit(0);
}

/* display the version of NetBSD gzip */
static void
display_version(void)
{

        fprintf(stderr, "%s\n", gzip_version);
        exit(0);
}

#ifndef NO_BZIP2_SUPPORT
#include "unbzip2.c"
#endif
#ifndef NO_COMPRESS_SUPPORT
#include "zuncompress.c"
#endif
#ifndef NO_PACK_SUPPORT
#include "unpack.c"
#endif
#ifndef NO_XZ_SUPPORT
#include "unxz.c"
#endif
#ifndef NO_LZ_SUPPORT
#include "unlz.c"
#endif
#ifndef NO_ZSTD_SUPPORT
#include "unzstd.c"
#endif

static ssize_t
read_retry(int fd, void *buf, size_t sz)
{
        char *cp = buf;
        size_t left = MIN(sz, (size_t) SSIZE_MAX);

        while (left > 0) {
                ssize_t ret;

                ret = read(fd, cp, left);
                if (ret == -1) {
                        return ret;
                } else if (ret == 0) {
                        break; /* EOF */
                }
                cp += ret;
                left -= ret;
        }

        return sz - left;
}

static ssize_t
write_retry(int fd, const void *buf, size_t sz)
{
        const char *cp = buf;
        size_t left = MIN(sz, (size_t) SSIZE_MAX);

        while (left > 0) {
                ssize_t ret;

                ret = write(fd, cp, left);
                if (ret == -1) {
                        return ret;
                } else if (ret == 0) {
                        abort();        /* Can't happen */
                }
                cp += ret;
                left -= ret;
        }

        return sz - left;
}