Chris@4: /* zpipe.c: example of proper use of zlib's inflate() and deflate()
Chris@4:    Not copyrighted -- provided to the public domain
Chris@4:    Version 1.4  11 December 2005  Mark Adler */
Chris@4: 
Chris@4: /* Version history:
Chris@4:    1.0  30 Oct 2004  First version
Chris@4:    1.1   8 Nov 2004  Add void casting for unused return values
Chris@4:                      Use switch statement for inflate() return values
Chris@4:    1.2   9 Nov 2004  Add assertions to document zlib guarantees
Chris@4:    1.3   6 Apr 2005  Remove incorrect assertion in inf()
Chris@4:    1.4  11 Dec 2005  Add hack to avoid MSDOS end-of-line conversions
Chris@4:                      Avoid some compiler warnings for input and output buffers
Chris@4:  */
Chris@4: 
Chris@4: #include <stdio.h>
Chris@4: #include <string.h>
Chris@4: #include <assert.h>
Chris@4: #include "zlib.h"
Chris@4: 
Chris@4: #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
Chris@4: #  include <fcntl.h>
Chris@4: #  include <io.h>
Chris@4: #  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
Chris@4: #else
Chris@4: #  define SET_BINARY_MODE(file)
Chris@4: #endif
Chris@4: 
Chris@4: #define CHUNK 16384
Chris@4: 
Chris@4: /* Compress from file source to file dest until EOF on source.
Chris@4:    def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
Chris@4:    allocated for processing, Z_STREAM_ERROR if an invalid compression
Chris@4:    level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
Chris@4:    version of the library linked do not match, or Z_ERRNO if there is
Chris@4:    an error reading or writing the files. */
Chris@4: int def(FILE *source, FILE *dest, int level)
Chris@4: {
Chris@4:     int ret, flush;
Chris@4:     unsigned have;
Chris@4:     z_stream strm;
Chris@4:     unsigned char in[CHUNK];
Chris@4:     unsigned char out[CHUNK];
Chris@4: 
Chris@4:     /* allocate deflate state */
Chris@4:     strm.zalloc = Z_NULL;
Chris@4:     strm.zfree = Z_NULL;
Chris@4:     strm.opaque = Z_NULL;
Chris@4:     ret = deflateInit(&strm, level);
Chris@4:     if (ret != Z_OK)
Chris@4:         return ret;
Chris@4: 
Chris@4:     /* compress until end of file */
Chris@4:     do {
Chris@4:         strm.avail_in = fread(in, 1, CHUNK, source);
Chris@4:         if (ferror(source)) {
Chris@4:             (void)deflateEnd(&strm);
Chris@4:             return Z_ERRNO;
Chris@4:         }
Chris@4:         flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
Chris@4:         strm.next_in = in;
Chris@4: 
Chris@4:         /* run deflate() on input until output buffer not full, finish
Chris@4:            compression if all of source has been read in */
Chris@4:         do {
Chris@4:             strm.avail_out = CHUNK;
Chris@4:             strm.next_out = out;
Chris@4:             ret = deflate(&strm, flush);    /* no bad return value */
Chris@4:             assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
Chris@4:             have = CHUNK - strm.avail_out;
Chris@4:             if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
Chris@4:                 (void)deflateEnd(&strm);
Chris@4:                 return Z_ERRNO;
Chris@4:             }
Chris@4:         } while (strm.avail_out == 0);
Chris@4:         assert(strm.avail_in == 0);     /* all input will be used */
Chris@4: 
Chris@4:         /* done when last data in file processed */
Chris@4:     } while (flush != Z_FINISH);
Chris@4:     assert(ret == Z_STREAM_END);        /* stream will be complete */
Chris@4: 
Chris@4:     /* clean up and return */
Chris@4:     (void)deflateEnd(&strm);
Chris@4:     return Z_OK;
Chris@4: }
Chris@4: 
Chris@4: /* Decompress from file source to file dest until stream ends or EOF.
Chris@4:    inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
Chris@4:    allocated for processing, Z_DATA_ERROR if the deflate data is
Chris@4:    invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
Chris@4:    the version of the library linked do not match, or Z_ERRNO if there
Chris@4:    is an error reading or writing the files. */
Chris@4: int inf(FILE *source, FILE *dest)
Chris@4: {
Chris@4:     int ret;
Chris@4:     unsigned have;
Chris@4:     z_stream strm;
Chris@4:     unsigned char in[CHUNK];
Chris@4:     unsigned char out[CHUNK];
Chris@4: 
Chris@4:     /* allocate inflate state */
Chris@4:     strm.zalloc = Z_NULL;
Chris@4:     strm.zfree = Z_NULL;
Chris@4:     strm.opaque = Z_NULL;
Chris@4:     strm.avail_in = 0;
Chris@4:     strm.next_in = Z_NULL;
Chris@4:     ret = inflateInit(&strm);
Chris@4:     if (ret != Z_OK)
Chris@4:         return ret;
Chris@4: 
Chris@4:     /* decompress until deflate stream ends or end of file */
Chris@4:     do {
Chris@4:         strm.avail_in = fread(in, 1, CHUNK, source);
Chris@4:         if (ferror(source)) {
Chris@4:             (void)inflateEnd(&strm);
Chris@4:             return Z_ERRNO;
Chris@4:         }
Chris@4:         if (strm.avail_in == 0)
Chris@4:             break;
Chris@4:         strm.next_in = in;
Chris@4: 
Chris@4:         /* run inflate() on input until output buffer not full */
Chris@4:         do {
Chris@4:             strm.avail_out = CHUNK;
Chris@4:             strm.next_out = out;
Chris@4:             ret = inflate(&strm, Z_NO_FLUSH);
Chris@4:             assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
Chris@4:             switch (ret) {
Chris@4:             case Z_NEED_DICT:
Chris@4:                 ret = Z_DATA_ERROR;     /* and fall through */
Chris@4:             case Z_DATA_ERROR:
Chris@4:             case Z_MEM_ERROR:
Chris@4:                 (void)inflateEnd(&strm);
Chris@4:                 return ret;
Chris@4:             }
Chris@4:             have = CHUNK - strm.avail_out;
Chris@4:             if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
Chris@4:                 (void)inflateEnd(&strm);
Chris@4:                 return Z_ERRNO;
Chris@4:             }
Chris@4:         } while (strm.avail_out == 0);
Chris@4: 
Chris@4:         /* done when inflate() says it's done */
Chris@4:     } while (ret != Z_STREAM_END);
Chris@4: 
Chris@4:     /* clean up and return */
Chris@4:     (void)inflateEnd(&strm);
Chris@4:     return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
Chris@4: }
Chris@4: 
Chris@4: /* report a zlib or i/o error */
Chris@4: void zerr(int ret)
Chris@4: {
Chris@4:     fputs("zpipe: ", stderr);
Chris@4:     switch (ret) {
Chris@4:     case Z_ERRNO:
Chris@4:         if (ferror(stdin))
Chris@4:             fputs("error reading stdin\n", stderr);
Chris@4:         if (ferror(stdout))
Chris@4:             fputs("error writing stdout\n", stderr);
Chris@4:         break;
Chris@4:     case Z_STREAM_ERROR:
Chris@4:         fputs("invalid compression level\n", stderr);
Chris@4:         break;
Chris@4:     case Z_DATA_ERROR:
Chris@4:         fputs("invalid or incomplete deflate data\n", stderr);
Chris@4:         break;
Chris@4:     case Z_MEM_ERROR:
Chris@4:         fputs("out of memory\n", stderr);
Chris@4:         break;
Chris@4:     case Z_VERSION_ERROR:
Chris@4:         fputs("zlib version mismatch!\n", stderr);
Chris@4:     }
Chris@4: }
Chris@4: 
Chris@4: /* compress or decompress from stdin to stdout */
Chris@4: int main(int argc, char **argv)
Chris@4: {
Chris@4:     int ret;
Chris@4: 
Chris@4:     /* avoid end-of-line conversions */
Chris@4:     SET_BINARY_MODE(stdin);
Chris@4:     SET_BINARY_MODE(stdout);
Chris@4: 
Chris@4:     /* do compression if no arguments */
Chris@4:     if (argc == 1) {
Chris@4:         ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
Chris@4:         if (ret != Z_OK)
Chris@4:             zerr(ret);
Chris@4:         return ret;
Chris@4:     }
Chris@4: 
Chris@4:     /* do decompression if -d specified */
Chris@4:     else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
Chris@4:         ret = inf(stdin, stdout);
Chris@4:         if (ret != Z_OK)
Chris@4:             zerr(ret);
Chris@4:         return ret;
Chris@4:     }
Chris@4: 
Chris@4:     /* otherwise, report usage */
Chris@4:     else {
Chris@4:         fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr);
Chris@4:         return 1;
Chris@4:     }
Chris@4: }