distrib/utils/zcat/zcat.c

   1 /*      $NetBSD: zcat.c,v 1.2 1996/09/24 20:40:11 gwr Exp $     */
   2
   3 /* mini zcat.c -- a minimal zcat using the zlib compression library
   4  * Copyright (C) 1995-1996 Jean-loup Gailly.
   5  * For conditions of distribution and use, see copyright notice in zlib.h
   6  */
   7
   8 /*
   9  * Credits, History:
  10  * This program is a reduced version of the minigzip.c
  11  * program originally written by Jean-loup Gailly.
  12  * This reduction is the work of Gordon Ross.
  13  */
  14
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18
  19 #include "zlib.h"
  20
  21 #define BUFLEN 4096
  22
  23 char *prog;
  24
  25 void error           __P((const char *msg));
  26 void gz_uncompress   __P((gzFile in, FILE   *out));
  27 int  main            __P((int argc, char *argv[]));
  28
  29 /* ===========================================================================
  30  * Display error message and exit
  31  */
  32 void error(msg)
  33     const char *msg;
  34 {
  35     fprintf(stderr, "%s: %s\n", prog, msg);
  36     exit(1);
  37 }
  38
  39 /* ===========================================================================
  40  * Uncompress input to output then close both files.
  41  */
  42 void gz_uncompress(in, out)
  43     gzFile in;
  44     FILE   *out;
  45 {
  46     char buf[BUFLEN];
  47     int len;
  48     int err;
  49
  50     for (;;) {
  51         len = gzread(in, buf, sizeof(buf));
  52         if (len < 0) error (gzerror(in, &err));
  53         if (len == 0) break;
  54
  55         if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
  56             error("failed fwrite");
  57         }
  58     }
  59     if (fclose(out)) error("failed fclose");
  60
  61     if (gzclose(in) != Z_OK) error("failed gzclose");
  62 }
  63
  64
  65 /* ===========================================================================
  66  * Usage:  zcat [files...]
  67  */
  68
  69 int main(argc, argv)
  70     int argc;
  71     char *argv[];
  72 {
  73     gzFile zfp;
  74
  75         /* save program name and skip */
  76     prog = argv[0];
  77     argc--, argv++;
  78
  79         /* ignore any switches */
  80         while (*argv && (**argv == '-')) {
  81         argc--, argv++;
  82     }
  83
  84     if (argc == 0) {
  85                 zfp = gzdopen(fileno(stdin), "rb");
  86                 if (zfp == NULL)
  87                         error("can't gzdopen stdin");
  88                 gz_uncompress(zfp, stdout);
  89                 return 0;
  90     }
  91
  92         do {
  93                 /* file_uncompress(*argv); */
  94                 zfp = gzopen(*argv, "rb");
  95                 if (zfp == NULL) {
  96                         fprintf(stderr, "%s: can't gzopen %s\n", prog, *argv);
  97                         exit(1);
  98                 }
  99                 gz_uncompress(zfp, stdout);
 100         } while (argv++, --argc);
 101     return 0; /* to avoid warning */
 102 }
 103
 104
 105 /*
 106  * XXX: hacks to keep gzio.c from pulling in deflate stuff
 107  */
 108
 109 int deflateInit2_ (z_streamp strm, int  level, int  method,
 110                                     int windowBits, int memLevel, int strategy,
 111                                     const char *version, int stream_size)
 112 {
 113         return(-1);
 114 }
 115
 116 int deflate (z_streamp strm, int flush)
 117 {
 118         return(-1);
 119 }
 120
 121 int deflateEnd (z_streamp strm)
 122 {
 123         return(-1);
 124 }
 125
 126 int deflateParams (z_streamp strm, int level, int strategy)
 127 {
 128         return(Z_STREAM_ERROR);
 129 }