misc/piggyback/zpipe.c

/* zpipe.c: example of proper use of zlib's inflate() and deflate()
   Not copyrighted -- provided to the public domain
   Version 1.2  9 November 2004  Mark Adler */

/* Version history:
   1.0  30 Oct 2004  First version
   1.1   8 Nov 2004  Add void casting for unused return values
                     Use switch statement for inflate() return values
   1.2   9 Nov 2004  Add assertions to document zlib guarantees
 */

#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "zlib.h"

#define CHUNK 16384

/* Compress from file source to file dest until EOF on source.
   def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
   allocated for processing, Z_STREAM_ERROR if an invalid compression
   level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
   version of the library linked do not match, or Z_ERRNO if there is
   an error reading or writing the files. */
int def(FILE *source, FILE *dest, int level)
{
    int ret, flush;
    unsigned have;
    z_stream strm;
    char in[CHUNK];
    char out[CHUNK];

    /* allocate deflate state */
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    ret = deflateInit(&strm, level);
    if (ret != Z_OK)
        return ret;

    /* compress until end of file */
    do {
        strm.avail_in = fread(in, 1, CHUNK, source);
        if (ferror(source)) {
            (void)deflateEnd(&strm);
            return Z_ERRNO;
        }
        flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
        strm.next_in = in;

        /* run deflate() on input until output buffer not full, finish
           compression if all of source has been read in */
        do {
            strm.avail_out = CHUNK;
            strm.next_out = out;
            ret = deflate(&strm, flush);    /* no bad return value */
            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
            have = CHUNK - strm.avail_out;
            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
                (void)deflateEnd(&strm);
                return Z_ERRNO;
            }
        } while (strm.avail_out == 0);
        assert(strm.avail_in == 0);     /* all input will be used */

        /* done when last data in file processed */
    } while (flush != Z_FINISH);
    assert(ret == Z_STREAM_END);        /* stream will be complete */

    /* clean up and return */
    (void)deflateEnd(&strm);
    return Z_OK;
}

/* Decompress from file source to file dest until stream ends or EOF.
   inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
   allocated for processing, Z_DATA_ERROR if the deflate data is
   invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
   the version of the library linked do not match, or Z_ERRNO if there
   is an error reading or writing the files. */
int inf(FILE *source, FILE *dest)
{
    int ret;
    unsigned have;
    z_stream strm;
    char in[CHUNK];
    char out[CHUNK];

    /* allocate inflate state */
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    strm.avail_in = 0;
    strm.next_in = Z_NULL;
    ret = inflateInit(&strm);
    if (ret != Z_OK)
        return ret;

    /* decompress until deflate stream ends or end of file */
    do {
        strm.avail_in = fread(in, 1, CHUNK, source);
        if (ferror(source)) {
            (void)inflateEnd(&strm);
            return Z_ERRNO;
        }
        if (strm.avail_in == 0)
            break;
        strm.next_in = in;

        /* run inflate() on input until output buffer not full */
        do {
            strm.avail_out = CHUNK;
            strm.next_out = out;
            ret = inflate(&strm, Z_NO_FLUSH);
            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
            switch (ret) {
            case Z_NEED_DICT:
                ret = Z_DATA_ERROR;     /* and fall through */
            case Z_DATA_ERROR:
            case Z_MEM_ERROR:
                (void)inflateEnd(&strm);
                return ret;
            }
            have = CHUNK - strm.avail_out;
            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
                (void)inflateEnd(&strm);
                return Z_ERRNO;
            }
        } while (strm.avail_out == 0);
        assert(strm.avail_in == 0);     /* all input will be used */

        /* done when inflate() says it's done */
    } while (ret != Z_STREAM_END);

    /* clean up and return */
    (void)inflateEnd(&strm);
    return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}

/* report a zlib or i/o error */
void zerr(int ret)
{
    fputs("zpipe: ", stderr);
    switch (ret) {
    case Z_ERRNO:
        if (ferror(stdin))
            fputs("error reading stdin\n", stderr);
        if (ferror(stdout))
            fputs("error writing stdout\n", stderr);
        break;
    case Z_STREAM_ERROR:
        fputs("invalid compression level\n", stderr);
        break;
    case Z_DATA_ERROR:
        fputs("invalid or incomplete deflate data\n", stderr);
        break;
    case Z_MEM_ERROR:
        fputs("out of memory\n", stderr);
        break;
    case Z_VERSION_ERROR:
        fputs("zlib version mismatch!\n", stderr);
    }
}
1	torben	328	/* zpipe.c: example of proper use of zlib's inflate() and deflate()
2			Not copyrighted -- provided to the public domain
3			Version 1.2 9 November 2004 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			*/
11
12			#include <stdio.h>
13			#include <string.h>
14			#include <assert.h>
15			#include "zlib.h"
16
17			#define CHUNK 16384
18
19			/* Compress from file source to file dest until EOF on source.
20			def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
21			allocated for processing, Z_STREAM_ERROR if an invalid compression
22			level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
23			version of the library linked do not match, or Z_ERRNO if there is
24			an error reading or writing the files. */
25			int def(FILE source, FILE dest, int level)
26			{
27			int ret, flush;
28			unsigned have;
29			z_stream strm;
30			char in[CHUNK];
31			char out[CHUNK];
32
33			/* allocate deflate state */
34			strm.zalloc = Z_NULL;
35			strm.zfree = Z_NULL;
36			strm.opaque = Z_NULL;
37			ret = deflateInit(&strm, level);
38			if (ret != Z_OK)
39			return ret;
40
41			/* compress until end of file */
42			do {
43			strm.avail_in = fread(in, 1, CHUNK, source);
44			if (ferror(source)) {
45			(void)deflateEnd(&strm);
46			return Z_ERRNO;
47			}
48			flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
49			strm.next_in = in;
50
51			/* run deflate() on input until output buffer not full, finish
52			compression if all of source has been read in */
53			do {
54			strm.avail_out = CHUNK;
55			strm.next_out = out;
56			ret = deflate(&strm, flush); /* no bad return value */
57			assert(ret != Z_STREAM_ERROR); /* state not clobbered */
58			have = CHUNK - strm.avail_out;
59			if (fwrite(out, 1, have, dest) != have \|\| ferror(dest)) {
60			(void)deflateEnd(&strm);
61			return Z_ERRNO;
62			}
63			} while (strm.avail_out == 0);
64			assert(strm.avail_in == 0); /* all input will be used */
65
66			/* done when last data in file processed */
67			} while (flush != Z_FINISH);
68			assert(ret == Z_STREAM_END); /* stream will be complete */
69
70			/* clean up and return */
71			(void)deflateEnd(&strm);
72			return Z_OK;
73			}
74
75			/* Decompress from file source to file dest until stream ends or EOF.
76			inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
77			allocated for processing, Z_DATA_ERROR if the deflate data is
78			invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
79			the version of the library linked do not match, or Z_ERRNO if there
80			is an error reading or writing the files. */
81			int inf(FILE source, FILE dest)
82			{
83			int ret;
84			unsigned have;
85			z_stream strm;
86			char in[CHUNK];
87			char out[CHUNK];
88
89			/* allocate inflate state */
90			strm.zalloc = Z_NULL;
91			strm.zfree = Z_NULL;
92			strm.opaque = Z_NULL;
93			strm.avail_in = 0;
94			strm.next_in = Z_NULL;
95			ret = inflateInit(&strm);
96			if (ret != Z_OK)
97			return ret;
98
99			/* decompress until deflate stream ends or end of file */
100			do {
101			strm.avail_in = fread(in, 1, CHUNK, source);
102			if (ferror(source)) {
103			(void)inflateEnd(&strm);
104			return Z_ERRNO;
105			}
106			if (strm.avail_in == 0)
107			break;
108			strm.next_in = in;
109
110			/* run inflate() on input until output buffer not full */
111			do {
112			strm.avail_out = CHUNK;
113			strm.next_out = out;
114			ret = inflate(&strm, Z_NO_FLUSH);
115			assert(ret != Z_STREAM_ERROR); /* state not clobbered */
116			switch (ret) {
117			case Z_NEED_DICT:
118			ret = Z_DATA_ERROR; /* and fall through */
119			case Z_DATA_ERROR:
120			case Z_MEM_ERROR:
121			(void)inflateEnd(&strm);
122			return ret;
123			}
124			have = CHUNK - strm.avail_out;
125			if (fwrite(out, 1, have, dest) != have \|\| ferror(dest)) {
126			(void)inflateEnd(&strm);
127			return Z_ERRNO;
128			}
129			} while (strm.avail_out == 0);
130			assert(strm.avail_in == 0); /* all input will be used */
131
132			/* done when inflate() says it's done */
133			} while (ret != Z_STREAM_END);
134
135			/* clean up and return */
136			(void)inflateEnd(&strm);
137			return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
138			}
139
140			/* report a zlib or i/o error */
141			void zerr(int ret)
142			{
143			fputs("zpipe: ", stderr);
144			switch (ret) {
145			case Z_ERRNO:
146			if (ferror(stdin))
147			fputs("error reading stdin\n", stderr);
148			if (ferror(stdout))
149			fputs("error writing stdout\n", stderr);
150			break;
151			case Z_STREAM_ERROR:
152			fputs("invalid compression level\n", stderr);
153			break;
154			case Z_DATA_ERROR:
155			fputs("invalid or incomplete deflate data\n", stderr);
156			break;
157			case Z_MEM_ERROR:
158			fputs("out of memory\n", stderr);
159			break;
160			case Z_VERSION_ERROR:
161			fputs("zlib version mismatch!\n", stderr);
162			}
163			}