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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [zlib/] [examples/] [zpipe.c] - Blame information for rev 745

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Line No. Rev Author Line
1 745 jeremybenn
/* 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 1.2  9 November 2004  Mark Adler */
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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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 */
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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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#define CHUNK 16384
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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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    char in[CHUNK];
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    char out[CHUNK];
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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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    /* 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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        /* 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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        /* 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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    /* 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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/* 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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    char in[CHUNK];
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    char out[CHUNK];
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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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    /* 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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        /* 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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        /* done when inflate() says it's done */
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    } while (ret != Z_STREAM_END);
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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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/* 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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/* 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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    /* 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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    /* 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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    /* 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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}

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