| 1 | /* zpipe.c: example of proper use of zlib's inflate() and deflate() | 
 
 
 
 
 | 2 | Not copyrighted -- provided to the public domain | 
 
 
 
 
 | 3 | Version 1.4  11 December 2005  Mark Adler */ | 
 
 
 
 
 | 4 |  | 
 
 
 
 
 | 5 | /* Version history: | 
 
 
 
 
 | 6 | 1.0  30 Oct 2004  First version | 
 
 
 
 
 | 7 | 1.1   8 Nov 2004  Add void casting for unused return values | 
 
 
 
 
 | 8 | Use switch statement for inflate() return values | 
 
 
 
 
 | 9 | 1.2   9 Nov 2004  Add assertions to document zlib guarantees | 
 
 
 
 
 | 10 | 1.3   6 Apr 2005  Remove incorrect assertion in inf() | 
 
 
 
 
 | 11 | 1.4  11 Dec 2005  Add hack to avoid MSDOS end-of-line conversions | 
 
 
 
 
 | 12 | Avoid some compiler warnings for input and output buffers | 
 
 
 
 
 | 13 | */ | 
 
 
 
 
 | 14 |  | 
 
 
 
 
 | 15 | #include <stdio.h> | 
 
 
 
 
 | 16 | #include <string.h> | 
 
 
 
 
 | 17 | #include <assert.h> | 
 
 
 
 
 | 18 | #include "zlib.h" | 
 
 
 
 
 | 19 |  | 
 
 
 
 
 | 20 | #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__) | 
 
 
 
 
 | 21 | #  include <fcntl.h> | 
 
 
 
 
 | 22 | #  include <io.h> | 
 
 
 
 
 | 23 | #  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) | 
 
 
 
 
 | 24 | #else | 
 
 
 
 
 | 25 | #  define SET_BINARY_MODE(file) | 
 
 
 
 
 | 26 | #endif | 
 
 
 
 
 | 27 |  | 
 
 
 
 
 | 28 | #define CHUNK 16384 | 
 
 
 
 
 | 29 |  | 
 
 
 
 
 | 30 | /* Compress from file source to file dest until EOF on source. | 
 
 
 
 
 | 31 | def() returns Z_OK on success, Z_MEM_ERROR if memory could not be | 
 
 
 
 
 | 32 | allocated for processing, Z_STREAM_ERROR if an invalid compression | 
 
 
 
 
 | 33 | level is supplied, Z_VERSION_ERROR if the version of zlib.h and the | 
 
 
 
 
 | 34 | version of the library linked do not match, or Z_ERRNO if there is | 
 
 
 
 
 | 35 | an error reading or writing the files. */ | 
 
 
 
 
 | 36 | int def(FILE *source, FILE *dest, int level) | 
 
 
 
 
 | 37 | { | 
 
 
 
 
 | 38 | int ret, flush; | 
 
 
 
 
 | 39 | unsigned have; | 
 
 
 
 
 | 40 | z_stream strm; | 
 
 
 
 
 | 41 | unsigned char in[CHUNK]; | 
 
 
 
 
 | 42 | unsigned char out[CHUNK]; | 
 
 
 
 
 | 43 |  | 
 
 
 
 
 | 44 | /* allocate deflate state */ | 
 
 
 
 
 | 45 | strm.zalloc = Z_NULL; | 
 
 
 
 
 | 46 | strm.zfree = Z_NULL; | 
 
 
 
 
 | 47 | strm.opaque = Z_NULL; | 
 
 
 
 
 | 48 | ret = deflateInit(&strm, level); | 
 
 
 
 
 | 49 | if (ret != Z_OK) | 
 
 
 
 
 | 50 | return ret; | 
 
 
 
 
 | 51 |  | 
 
 
 
 
 | 52 | /* compress until end of file */ | 
 
 
 
 
 | 53 | do { | 
 
 
 
 
 | 54 | strm.avail_in = fread(in, 1, CHUNK, source); | 
 
 
 
 
 | 55 | if (ferror(source)) { | 
 
 
 
 
 | 56 | (void)deflateEnd(&strm); | 
 
 
 
 
 | 57 | return Z_ERRNO; | 
 
 
 
 
 | 58 | } | 
 
 
 
 
 | 59 | flush = feof(source) ? Z_FINISH : Z_NO_FLUSH; | 
 
 
 
 
 | 60 | strm.next_in = in; | 
 
 
 
 
 | 61 |  | 
 
 
 
 
 | 62 | /* run deflate() on input until output buffer not full, finish | 
 
 
 
 
 | 63 | compression if all of source has been read in */ | 
 
 
 
 
 | 64 | do { | 
 
 
 
 
 | 65 | strm.avail_out = CHUNK; | 
 
 
 
 
 | 66 | strm.next_out = out; | 
 
 
 
 
 | 67 | ret = deflate(&strm, flush);    /* no bad return value */ | 
 
 
 
 
 | 68 | assert(ret != Z_STREAM_ERROR);  /* state not clobbered */ | 
 
 
 
 
 | 69 | have = CHUNK - strm.avail_out; | 
 
 
 
 
 | 70 | if (fwrite(out, 1, have, dest) != have || ferror(dest)) { | 
 
 
 
 
 | 71 | (void)deflateEnd(&strm); | 
 
 
 
 
 | 72 | return Z_ERRNO; | 
 
 
 
 
 | 73 | } | 
 
 
 
 
 | 74 | } while (strm.avail_out == 0); | 
 
 
 
 
 | 75 | assert(strm.avail_in == 0);     /* all input will be used */ | 
 
 
 
 
 | 76 |  | 
 
 
 
 
 | 77 | /* done when last data in file processed */ | 
 
 
 
 
 | 78 | } while (flush != Z_FINISH); | 
 
 
 
 
 | 79 | assert(ret == Z_STREAM_END);        /* stream will be complete */ | 
 
 
 
 
 | 80 |  | 
 
 
 
 
 | 81 | /* clean up and return */ | 
 
 
 
 
 | 82 | (void)deflateEnd(&strm); | 
 
 
 
 
 | 83 | return Z_OK; | 
 
 
 
 
 | 84 | } | 
 
 
 
 
 | 85 |  | 
 
 
 
 
 | 86 | /* Decompress from file source to file dest until stream ends or EOF. | 
 
 
 
 
 | 87 | inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be | 
 
 
 
 
 | 88 | allocated for processing, Z_DATA_ERROR if the deflate data is | 
 
 
 
 
 | 89 | invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and | 
 
 
 
 
 | 90 | the version of the library linked do not match, or Z_ERRNO if there | 
 
 
 
 
 | 91 | is an error reading or writing the files. */ | 
 
 
 
 
 | 92 | int inf(FILE *source, FILE *dest) | 
 
 
 
 
 | 93 | { | 
 
 
 
 
 | 94 | int ret; | 
 
 
 
 
 | 95 | unsigned have; | 
 
 
 
 
 | 96 | z_stream strm; | 
 
 
 
 
 | 97 | unsigned char in[CHUNK]; | 
 
 
 
 
 | 98 | unsigned char out[CHUNK]; | 
 
 
 
 
 | 99 |  | 
 
 
 
 
 | 100 | /* allocate inflate state */ | 
 
 
 
 
 | 101 | strm.zalloc = Z_NULL; | 
 
 
 
 
 | 102 | strm.zfree = Z_NULL; | 
 
 
 
 
 | 103 | strm.opaque = Z_NULL; | 
 
 
 
 
 | 104 | strm.avail_in = 0; | 
 
 
 
 
 | 105 | strm.next_in = Z_NULL; | 
 
 
 
 
 | 106 | ret = inflateInit(&strm); | 
 
 
 
 
 | 107 | if (ret != Z_OK) | 
 
 
 
 
 | 108 | return ret; | 
 
 
 
 
 | 109 |  | 
 
 
 
 
 | 110 | /* decompress until deflate stream ends or end of file */ | 
 
 
 
 
 | 111 | do { | 
 
 
 
 
 | 112 | strm.avail_in = fread(in, 1, CHUNK, source); | 
 
 
 
 
 | 113 | if (ferror(source)) { | 
 
 
 
 
 | 114 | (void)inflateEnd(&strm); | 
 
 
 
 
 | 115 | return Z_ERRNO; | 
 
 
 
 
 | 116 | } | 
 
 
 
 
 | 117 | if (strm.avail_in == 0) | 
 
 
 
 
 | 118 | break; | 
 
 
 
 
 | 119 | strm.next_in = in; | 
 
 
 
 
 | 120 |  | 
 
 
 
 
 | 121 | /* run inflate() on input until output buffer not full */ | 
 
 
 
 
 | 122 | do { | 
 
 
 
 
 | 123 | strm.avail_out = CHUNK; | 
 
 
 
 
 | 124 | strm.next_out = out; | 
 
 
 
 
 | 125 | ret = inflate(&strm, Z_NO_FLUSH); | 
 
 
 
 
 | 126 | assert(ret != Z_STREAM_ERROR);  /* state not clobbered */ | 
 
 
 
 
 | 127 | switch (ret) { | 
 
 
 
 
 | 128 | case Z_NEED_DICT: | 
 
 
 
 
 | 129 | ret = Z_DATA_ERROR;     /* and fall through */ | 
 
 
 
 
 | 130 | case Z_DATA_ERROR: | 
 
 
 
 
 | 131 | case Z_MEM_ERROR: | 
 
 
 
 
 | 132 | (void)inflateEnd(&strm); | 
 
 
 
 
 | 133 | return ret; | 
 
 
 
 
 | 134 | } | 
 
 
 
 
 | 135 | have = CHUNK - strm.avail_out; | 
 
 
 
 
 | 136 | if (fwrite(out, 1, have, dest) != have || ferror(dest)) { | 
 
 
 
 
 | 137 | (void)inflateEnd(&strm); | 
 
 
 
 
 | 138 | return Z_ERRNO; | 
 
 
 
 
 | 139 | } | 
 
 
 
 
 | 140 | } while (strm.avail_out == 0); | 
 
 
 
 
 | 141 |  | 
 
 
 
 
 | 142 | /* done when inflate() says it's done */ | 
 
 
 
 
 | 143 | } while (ret != Z_STREAM_END); | 
 
 
 
 
 | 144 |  | 
 
 
 
 
 | 145 | /* clean up and return */ | 
 
 
 
 
 | 146 | (void)inflateEnd(&strm); | 
 
 
 
 
 | 147 | return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR; | 
 
 
 
 
 | 148 | } | 
 
 
 
 
 | 149 |  | 
 
 
 
 
 | 150 | /* report a zlib or i/o error */ | 
 
 
 
 
 | 151 | void zerr(int ret) | 
 
 
 
 
 | 152 | { | 
 
 
 
 
 | 153 | fputs("zpipe: ", stderr); | 
 
 
 
 
 | 154 | switch (ret) { | 
 
 
 
 
 | 155 | case Z_ERRNO: | 
 
 
 
 
 | 156 | if (ferror(stdin)) | 
 
 
 
 
 | 157 | fputs("error reading stdin\n", stderr); | 
 
 
 
 
 | 158 | if (ferror(stdout)) | 
 
 
 
 
 | 159 | fputs("error writing stdout\n", stderr); | 
 
 
 
 
 | 160 | break; | 
 
 
 
 
 | 161 | case Z_STREAM_ERROR: | 
 
 
 
 
 | 162 | fputs("invalid compression level\n", stderr); | 
 
 
 
 
 | 163 | break; | 
 
 
 
 
 | 164 | case Z_DATA_ERROR: | 
 
 
 
 
 | 165 | fputs("invalid or incomplete deflate data\n", stderr); | 
 
 
 
 
 | 166 | break; | 
 
 
 
 
 | 167 | case Z_MEM_ERROR: | 
 
 
 
 
 | 168 | fputs("out of memory\n", stderr); | 
 
 
 
 
 | 169 | break; | 
 
 
 
 
 | 170 | case Z_VERSION_ERROR: | 
 
 
 
 
 | 171 | fputs("zlib version mismatch!\n", stderr); | 
 
 
 
 
 | 172 | } | 
 
 
 
 
 | 173 | } | 
 
 
 
 
 | 174 |  | 
 
 
 
 
 | 175 | /* compress or decompress from stdin to stdout */ | 
 
 
 
 
 | 176 | int main(int argc, char **argv) | 
 
 
 
 
 | 177 | { | 
 
 
 
 
 | 178 | int ret; | 
 
 
 
 
 | 179 |  | 
 
 
 
 
 | 180 | /* avoid end-of-line conversions */ | 
 
 
 
 
 | 181 | SET_BINARY_MODE(stdin); | 
 
 
 
 
 | 182 | SET_BINARY_MODE(stdout); | 
 
 
 
 
 | 183 |  | 
 
 
 
 
 | 184 | /* do compression if no arguments */ | 
 
 
 
 
 | 185 | if (argc == 1) { | 
 
 
 
 
 | 186 | ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION); | 
 
 
 
 
 | 187 | if (ret != Z_OK) | 
 
 
 
 
 | 188 | zerr(ret); | 
 
 
 
 
 | 189 | return ret; | 
 
 
 
 
 | 190 | } | 
 
 
 
 
 | 191 |  | 
 
 
 
 
 | 192 | /* do decompression if -d specified */ | 
 
 
 
 
 | 193 | else if (argc == 2 && strcmp(argv[1], "-d") == 0) { | 
 
 
 
 
 | 194 | ret = inf(stdin, stdout); | 
 
 
 
 
 | 195 | if (ret != Z_OK) | 
 
 
 
 
 | 196 | zerr(ret); | 
 
 
 
 
 | 197 | return ret; | 
 
 
 
 
 | 198 | } | 
 
 
 
 
 | 199 |  | 
 
 
 
 
 | 200 | /* otherwise, report usage */ | 
 
 
 
 
 | 201 | else { | 
 
 
 
 
 | 202 | fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr); | 
 
 
 
 
 | 203 | return 1; | 
 
 
 
 
 | 204 | } | 
 
 
 
 
 | 205 | } |