cannam@89: /* zpipe.c: example of proper use of zlib's inflate() and deflate()
cannam@89:    Not copyrighted -- provided to the public domain
cannam@89:    Version 1.4  11 December 2005  Mark Adler */
cannam@89: 
cannam@89: /* Version history:
cannam@89:    1.0  30 Oct 2004  First version
cannam@89:    1.1   8 Nov 2004  Add void casting for unused return values
cannam@89:                      Use switch statement for inflate() return values
cannam@89:    1.2   9 Nov 2004  Add assertions to document zlib guarantees
cannam@89:    1.3   6 Apr 2005  Remove incorrect assertion in inf()
cannam@89:    1.4  11 Dec 2005  Add hack to avoid MSDOS end-of-line conversions
cannam@89:                      Avoid some compiler warnings for input and output buffers
cannam@89:  */
cannam@89: 
cannam@89: #include <stdio.h>
cannam@89: #include <string.h>
cannam@89: #include <assert.h>
cannam@89: #include "zlib.h"
cannam@89: 
cannam@89: #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
cannam@89: #  include <fcntl.h>
cannam@89: #  include <io.h>
cannam@89: #  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
cannam@89: #else
cannam@89: #  define SET_BINARY_MODE(file)
cannam@89: #endif
cannam@89: 
cannam@89: #define CHUNK 16384
cannam@89: 
cannam@89: /* Compress from file source to file dest until EOF on source.
cannam@89:    def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
cannam@89:    allocated for processing, Z_STREAM_ERROR if an invalid compression
cannam@89:    level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
cannam@89:    version of the library linked do not match, or Z_ERRNO if there is
cannam@89:    an error reading or writing the files. */
cannam@89: int def(FILE *source, FILE *dest, int level)
cannam@89: {
cannam@89:     int ret, flush;
cannam@89:     unsigned have;
cannam@89:     z_stream strm;
cannam@89:     unsigned char in[CHUNK];
cannam@89:     unsigned char out[CHUNK];
cannam@89: 
cannam@89:     /* allocate deflate state */
cannam@89:     strm.zalloc = Z_NULL;
cannam@89:     strm.zfree = Z_NULL;
cannam@89:     strm.opaque = Z_NULL;
cannam@89:     ret = deflateInit(&strm, level);
cannam@89:     if (ret != Z_OK)
cannam@89:         return ret;
cannam@89: 
cannam@89:     /* compress until end of file */
cannam@89:     do {
cannam@89:         strm.avail_in = fread(in, 1, CHUNK, source);
cannam@89:         if (ferror(source)) {
cannam@89:             (void)deflateEnd(&strm);
cannam@89:             return Z_ERRNO;
cannam@89:         }
cannam@89:         flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
cannam@89:         strm.next_in = in;
cannam@89: 
cannam@89:         /* run deflate() on input until output buffer not full, finish
cannam@89:            compression if all of source has been read in */
cannam@89:         do {
cannam@89:             strm.avail_out = CHUNK;
cannam@89:             strm.next_out = out;
cannam@89:             ret = deflate(&strm, flush);    /* no bad return value */
cannam@89:             assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
cannam@89:             have = CHUNK - strm.avail_out;
cannam@89:             if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
cannam@89:                 (void)deflateEnd(&strm);
cannam@89:                 return Z_ERRNO;
cannam@89:             }
cannam@89:         } while (strm.avail_out == 0);
cannam@89:         assert(strm.avail_in == 0);     /* all input will be used */
cannam@89: 
cannam@89:         /* done when last data in file processed */
cannam@89:     } while (flush != Z_FINISH);
cannam@89:     assert(ret == Z_STREAM_END);        /* stream will be complete */
cannam@89: 
cannam@89:     /* clean up and return */
cannam@89:     (void)deflateEnd(&strm);
cannam@89:     return Z_OK;
cannam@89: }
cannam@89: 
cannam@89: /* Decompress from file source to file dest until stream ends or EOF.
cannam@89:    inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
cannam@89:    allocated for processing, Z_DATA_ERROR if the deflate data is
cannam@89:    invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
cannam@89:    the version of the library linked do not match, or Z_ERRNO if there
cannam@89:    is an error reading or writing the files. */
cannam@89: int inf(FILE *source, FILE *dest)
cannam@89: {
cannam@89:     int ret;
cannam@89:     unsigned have;
cannam@89:     z_stream strm;
cannam@89:     unsigned char in[CHUNK];
cannam@89:     unsigned char out[CHUNK];
cannam@89: 
cannam@89:     /* allocate inflate state */
cannam@89:     strm.zalloc = Z_NULL;
cannam@89:     strm.zfree = Z_NULL;
cannam@89:     strm.opaque = Z_NULL;
cannam@89:     strm.avail_in = 0;
cannam@89:     strm.next_in = Z_NULL;
cannam@89:     ret = inflateInit(&strm);
cannam@89:     if (ret != Z_OK)
cannam@89:         return ret;
cannam@89: 
cannam@89:     /* decompress until deflate stream ends or end of file */
cannam@89:     do {
cannam@89:         strm.avail_in = fread(in, 1, CHUNK, source);
cannam@89:         if (ferror(source)) {
cannam@89:             (void)inflateEnd(&strm);
cannam@89:             return Z_ERRNO;
cannam@89:         }
cannam@89:         if (strm.avail_in == 0)
cannam@89:             break;
cannam@89:         strm.next_in = in;
cannam@89: 
cannam@89:         /* run inflate() on input until output buffer not full */
cannam@89:         do {
cannam@89:             strm.avail_out = CHUNK;
cannam@89:             strm.next_out = out;
cannam@89:             ret = inflate(&strm, Z_NO_FLUSH);
cannam@89:             assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
cannam@89:             switch (ret) {
cannam@89:             case Z_NEED_DICT:
cannam@89:                 ret = Z_DATA_ERROR;     /* and fall through */
cannam@89:             case Z_DATA_ERROR:
cannam@89:             case Z_MEM_ERROR:
cannam@89:                 (void)inflateEnd(&strm);
cannam@89:                 return ret;
cannam@89:             }
cannam@89:             have = CHUNK - strm.avail_out;
cannam@89:             if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
cannam@89:                 (void)inflateEnd(&strm);
cannam@89:                 return Z_ERRNO;
cannam@89:             }
cannam@89:         } while (strm.avail_out == 0);
cannam@89: 
cannam@89:         /* done when inflate() says it's done */
cannam@89:     } while (ret != Z_STREAM_END);
cannam@89: 
cannam@89:     /* clean up and return */
cannam@89:     (void)inflateEnd(&strm);
cannam@89:     return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
cannam@89: }
cannam@89: 
cannam@89: /* report a zlib or i/o error */
cannam@89: void zerr(int ret)
cannam@89: {
cannam@89:     fputs("zpipe: ", stderr);
cannam@89:     switch (ret) {
cannam@89:     case Z_ERRNO:
cannam@89:         if (ferror(stdin))
cannam@89:             fputs("error reading stdin\n", stderr);
cannam@89:         if (ferror(stdout))
cannam@89:             fputs("error writing stdout\n", stderr);
cannam@89:         break;
cannam@89:     case Z_STREAM_ERROR:
cannam@89:         fputs("invalid compression level\n", stderr);
cannam@89:         break;
cannam@89:     case Z_DATA_ERROR:
cannam@89:         fputs("invalid or incomplete deflate data\n", stderr);
cannam@89:         break;
cannam@89:     case Z_MEM_ERROR:
cannam@89:         fputs("out of memory\n", stderr);
cannam@89:         break;
cannam@89:     case Z_VERSION_ERROR:
cannam@89:         fputs("zlib version mismatch!\n", stderr);
cannam@89:     }
cannam@89: }
cannam@89: 
cannam@89: /* compress or decompress from stdin to stdout */
cannam@89: int main(int argc, char **argv)
cannam@89: {
cannam@89:     int ret;
cannam@89: 
cannam@89:     /* avoid end-of-line conversions */
cannam@89:     SET_BINARY_MODE(stdin);
cannam@89:     SET_BINARY_MODE(stdout);
cannam@89: 
cannam@89:     /* do compression if no arguments */
cannam@89:     if (argc == 1) {
cannam@89:         ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
cannam@89:         if (ret != Z_OK)
cannam@89:             zerr(ret);
cannam@89:         return ret;
cannam@89:     }
cannam@89: 
cannam@89:     /* do decompression if -d specified */
cannam@89:     else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
cannam@89:         ret = inf(stdin, stdout);
cannam@89:         if (ret != Z_OK)
cannam@89:             zerr(ret);
cannam@89:         return ret;
cannam@89:     }
cannam@89: 
cannam@89:     /* otherwise, report usage */
cannam@89:     else {
cannam@89:         fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr);
cannam@89:         return 1;
cannam@89:     }
cannam@89: }