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zcat.c revision 1.3 
      1 /*	$NetBSD: zcat.c,v 1.3 1998/11/12 16:49:47 thorpej 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 }
    130