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