1/* example.c -- usage example of the zlib compression library
2 * Copyright (C) 1995-1998 Jean-loup Gailly.
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/* @(#) $Id: example.c,v 1.1.1.1 2008/10/15 03:25:54 james26_jang Exp $ */
7
8#include <stdio.h>
9#include "zlib.h"
10
11#ifdef STDC
12#  include <string.h>
13#  include <stdlib.h>
14#else
15   extern void exit  OF((int));
16#endif
17
18#if defined(VMS) || defined(RISCOS)
19#  define TESTFILE "foo-gz"
20#else
21#  define TESTFILE "foo.gz"
22#endif
23
24#define CHECK_ERR(err, msg) { \
25    if (err != Z_OK) { \
26        fprintf(stderr, "%s error: %d\n", msg, err); \
27        exit(1); \
28    } \
29}
30
31const char hello[] = "hello, hello!";
32/* "hello world" would be more standard, but the repeated "hello"
33 * stresses the compression code better, sorry...
34 */
35
36const char dictionary[] = "hello";
37uLong dictId; /* Adler32 value of the dictionary */
38
39void test_compress      OF((Byte *compr, uLong comprLen,
40		            Byte *uncompr, uLong uncomprLen));
41void test_gzio          OF((const char *out, const char *in,
42		            Byte *uncompr, int uncomprLen));
43void test_deflate       OF((Byte *compr, uLong comprLen));
44void test_inflate       OF((Byte *compr, uLong comprLen,
45		            Byte *uncompr, uLong uncomprLen));
46void test_large_deflate OF((Byte *compr, uLong comprLen,
47		            Byte *uncompr, uLong uncomprLen));
48void test_large_inflate OF((Byte *compr, uLong comprLen,
49		            Byte *uncompr, uLong uncomprLen));
50void test_flush         OF((Byte *compr, uLong *comprLen));
51void test_sync          OF((Byte *compr, uLong comprLen,
52		            Byte *uncompr, uLong uncomprLen));
53void test_dict_deflate  OF((Byte *compr, uLong comprLen));
54void test_dict_inflate  OF((Byte *compr, uLong comprLen,
55		            Byte *uncompr, uLong uncomprLen));
56int  main               OF((int argc, char *argv[]));
57
58/* ===========================================================================
59 * Test compress() and uncompress()
60 */
61void test_compress(compr, comprLen, uncompr, uncomprLen)
62    Byte *compr, *uncompr;
63    uLong comprLen, uncomprLen;
64{
65    int err;
66    uLong len = strlen(hello)+1;
67
68    err = compress(compr, &comprLen, (const Bytef*)hello, len);
69    CHECK_ERR(err, "compress");
70
71    strcpy((char*)uncompr, "garbage");
72
73    err = uncompress(uncompr, &uncomprLen, compr, comprLen);
74    CHECK_ERR(err, "uncompress");
75
76    if (strcmp((char*)uncompr, hello)) {
77        fprintf(stderr, "bad uncompress\n");
78	exit(1);
79    } else {
80        printf("uncompress(): %s\n", (char *)uncompr);
81    }
82}
83
84/* ===========================================================================
85 * Test read/write of .gz files
86 */
87void test_gzio(out, in, uncompr, uncomprLen)
88    const char *out; /* compressed output file */
89    const char *in;  /* compressed input file */
90    Byte *uncompr;
91    int  uncomprLen;
92{
93    int err;
94    int len = strlen(hello)+1;
95    gzFile file;
96    z_off_t pos;
97
98    file = gzopen(out, "wb");
99    if (file == NULL) {
100        fprintf(stderr, "gzopen error\n");
101        exit(1);
102    }
103    gzputc(file, 'h');
104    if (gzputs(file, "ello") != 4) {
105        fprintf(stderr, "gzputs err: %s\n", gzerror(file, &err));
106	exit(1);
107    }
108    if (gzprintf(file, ", %s!", "hello") != 8) {
109        fprintf(stderr, "gzprintf err: %s\n", gzerror(file, &err));
110	exit(1);
111    }
112    gzseek(file, 1L, SEEK_CUR); /* add one zero byte */
113    gzclose(file);
114
115    file = gzopen(in, "rb");
116    if (file == NULL) {
117        fprintf(stderr, "gzopen error\n");
118    }
119    strcpy((char*)uncompr, "garbage");
120
121    uncomprLen = gzread(file, uncompr, (unsigned)uncomprLen);
122    if (uncomprLen != len) {
123        fprintf(stderr, "gzread err: %s\n", gzerror(file, &err));
124	exit(1);
125    }
126    if (strcmp((char*)uncompr, hello)) {
127        fprintf(stderr, "bad gzread: %s\n", (char*)uncompr);
128	exit(1);
129    } else {
130        printf("gzread(): %s\n", (char *)uncompr);
131    }
132
133    pos = gzseek(file, -8L, SEEK_CUR);
134    if (pos != 6 || gztell(file) != pos) {
135	fprintf(stderr, "gzseek error, pos=%ld, gztell=%ld\n",
136		(long)pos, (long)gztell(file));
137	exit(1);
138    }
139
140    if (gzgetc(file) != ' ') {
141	fprintf(stderr, "gzgetc error\n");
142	exit(1);
143    }
144
145    gzgets(file, (char*)uncompr, uncomprLen);
146    uncomprLen = strlen((char*)uncompr);
147    if (uncomprLen != 6) { /* "hello!" */
148        fprintf(stderr, "gzgets err after gzseek: %s\n", gzerror(file, &err));
149	exit(1);
150    }
151    if (strcmp((char*)uncompr, hello+7)) {
152        fprintf(stderr, "bad gzgets after gzseek\n");
153	exit(1);
154    } else {
155        printf("gzgets() after gzseek: %s\n", (char *)uncompr);
156    }
157
158    gzclose(file);
159}
160
161/* ===========================================================================
162 * Test deflate() with small buffers
163 */
164void test_deflate(compr, comprLen)
165    Byte *compr;
166    uLong comprLen;
167{
168    z_stream c_stream; /* compression stream */
169    int err;
170    int len = strlen(hello)+1;
171
172    c_stream.zalloc = (alloc_func)0;
173    c_stream.zfree = (free_func)0;
174    c_stream.opaque = (voidpf)0;
175
176    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
177    CHECK_ERR(err, "deflateInit");
178
179    c_stream.next_in  = (Bytef*)hello;
180    c_stream.next_out = compr;
181
182    while (c_stream.total_in != (uLong)len && c_stream.total_out < comprLen) {
183        c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
184        err = deflate(&c_stream, Z_NO_FLUSH);
185        CHECK_ERR(err, "deflate");
186    }
187    /* Finish the stream, still forcing small buffers: */
188    for (;;) {
189        c_stream.avail_out = 1;
190        err = deflate(&c_stream, Z_FINISH);
191        if (err == Z_STREAM_END) break;
192        CHECK_ERR(err, "deflate");
193    }
194
195    err = deflateEnd(&c_stream);
196    CHECK_ERR(err, "deflateEnd");
197}
198
199/* ===========================================================================
200 * Test inflate() with small buffers
201 */
202void test_inflate(compr, comprLen, uncompr, uncomprLen)
203    Byte *compr, *uncompr;
204    uLong comprLen, uncomprLen;
205{
206    int err;
207    z_stream d_stream; /* decompression stream */
208
209    strcpy((char*)uncompr, "garbage");
210
211    d_stream.zalloc = (alloc_func)0;
212    d_stream.zfree = (free_func)0;
213    d_stream.opaque = (voidpf)0;
214
215    d_stream.next_in  = compr;
216    d_stream.avail_in = 0;
217    d_stream.next_out = uncompr;
218
219    err = inflateInit(&d_stream);
220    CHECK_ERR(err, "inflateInit");
221
222    while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) {
223        d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
224        err = inflate(&d_stream, Z_NO_FLUSH);
225        if (err == Z_STREAM_END) break;
226        CHECK_ERR(err, "inflate");
227    }
228
229    err = inflateEnd(&d_stream);
230    CHECK_ERR(err, "inflateEnd");
231
232    if (strcmp((char*)uncompr, hello)) {
233        fprintf(stderr, "bad inflate\n");
234	exit(1);
235    } else {
236        printf("inflate(): %s\n", (char *)uncompr);
237    }
238}
239
240/* ===========================================================================
241 * Test deflate() with large buffers and dynamic change of compression level
242 */
243void test_large_deflate(compr, comprLen, uncompr, uncomprLen)
244    Byte *compr, *uncompr;
245    uLong comprLen, uncomprLen;
246{
247    z_stream c_stream; /* compression stream */
248    int err;
249
250    c_stream.zalloc = (alloc_func)0;
251    c_stream.zfree = (free_func)0;
252    c_stream.opaque = (voidpf)0;
253
254    err = deflateInit(&c_stream, Z_BEST_SPEED);
255    CHECK_ERR(err, "deflateInit");
256
257    c_stream.next_out = compr;
258    c_stream.avail_out = (uInt)comprLen;
259
260    /* At this point, uncompr is still mostly zeroes, so it should compress
261     * very well:
262     */
263    c_stream.next_in = uncompr;
264    c_stream.avail_in = (uInt)uncomprLen;
265    err = deflate(&c_stream, Z_NO_FLUSH);
266    CHECK_ERR(err, "deflate");
267    if (c_stream.avail_in != 0) {
268        fprintf(stderr, "deflate not greedy\n");
269	exit(1);
270    }
271
272    /* Feed in already compressed data and switch to no compression: */
273    deflateParams(&c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);
274    c_stream.next_in = compr;
275    c_stream.avail_in = (uInt)comprLen/2;
276    err = deflate(&c_stream, Z_NO_FLUSH);
277    CHECK_ERR(err, "deflate");
278
279    /* Switch back to compressing mode: */
280    deflateParams(&c_stream, Z_BEST_COMPRESSION, Z_FILTERED);
281    c_stream.next_in = uncompr;
282    c_stream.avail_in = (uInt)uncomprLen;
283    err = deflate(&c_stream, Z_NO_FLUSH);
284    CHECK_ERR(err, "deflate");
285
286    err = deflate(&c_stream, Z_FINISH);
287    if (err != Z_STREAM_END) {
288        fprintf(stderr, "deflate should report Z_STREAM_END\n");
289	exit(1);
290    }
291    err = deflateEnd(&c_stream);
292    CHECK_ERR(err, "deflateEnd");
293}
294
295/* ===========================================================================
296 * Test inflate() with large buffers
297 */
298void test_large_inflate(compr, comprLen, uncompr, uncomprLen)
299    Byte *compr, *uncompr;
300    uLong comprLen, uncomprLen;
301{
302    int err;
303    z_stream d_stream; /* decompression stream */
304
305    strcpy((char*)uncompr, "garbage");
306
307    d_stream.zalloc = (alloc_func)0;
308    d_stream.zfree = (free_func)0;
309    d_stream.opaque = (voidpf)0;
310
311    d_stream.next_in  = compr;
312    d_stream.avail_in = (uInt)comprLen;
313
314    err = inflateInit(&d_stream);
315    CHECK_ERR(err, "inflateInit");
316
317    for (;;) {
318        d_stream.next_out = uncompr;            /* discard the output */
319	d_stream.avail_out = (uInt)uncomprLen;
320        err = inflate(&d_stream, Z_NO_FLUSH);
321        if (err == Z_STREAM_END) break;
322        CHECK_ERR(err, "large inflate");
323    }
324
325    err = inflateEnd(&d_stream);
326    CHECK_ERR(err, "inflateEnd");
327
328    if (d_stream.total_out != 2*uncomprLen + comprLen/2) {
329        fprintf(stderr, "bad large inflate: %ld\n", d_stream.total_out);
330	exit(1);
331    } else {
332        printf("large_inflate(): OK\n");
333    }
334}
335
336/* ===========================================================================
337 * Test deflate() with full flush
338 */
339void test_flush(compr, comprLen)
340    Byte *compr;
341    uLong *comprLen;
342{
343    z_stream c_stream; /* compression stream */
344    int err;
345    int len = strlen(hello)+1;
346
347    c_stream.zalloc = (alloc_func)0;
348    c_stream.zfree = (free_func)0;
349    c_stream.opaque = (voidpf)0;
350
351    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
352    CHECK_ERR(err, "deflateInit");
353
354    c_stream.next_in  = (Bytef*)hello;
355    c_stream.next_out = compr;
356    c_stream.avail_in = 3;
357    c_stream.avail_out = (uInt)*comprLen;
358    err = deflate(&c_stream, Z_FULL_FLUSH);
359    CHECK_ERR(err, "deflate");
360
361    compr[3]++; /* force an error in first compressed block */
362    c_stream.avail_in = len - 3;
363
364    err = deflate(&c_stream, Z_FINISH);
365    if (err != Z_STREAM_END) {
366        CHECK_ERR(err, "deflate");
367    }
368    err = deflateEnd(&c_stream);
369    CHECK_ERR(err, "deflateEnd");
370
371    *comprLen = c_stream.total_out;
372}
373
374/* ===========================================================================
375 * Test inflateSync()
376 */
377void test_sync(compr, comprLen, uncompr, uncomprLen)
378    Byte *compr, *uncompr;
379    uLong comprLen, uncomprLen;
380{
381    int err;
382    z_stream d_stream; /* decompression stream */
383
384    strcpy((char*)uncompr, "garbage");
385
386    d_stream.zalloc = (alloc_func)0;
387    d_stream.zfree = (free_func)0;
388    d_stream.opaque = (voidpf)0;
389
390    d_stream.next_in  = compr;
391    d_stream.avail_in = 2; /* just read the zlib header */
392
393    err = inflateInit(&d_stream);
394    CHECK_ERR(err, "inflateInit");
395
396    d_stream.next_out = uncompr;
397    d_stream.avail_out = (uInt)uncomprLen;
398
399    inflate(&d_stream, Z_NO_FLUSH);
400    CHECK_ERR(err, "inflate");
401
402    d_stream.avail_in = (uInt)comprLen-2;   /* read all compressed data */
403    err = inflateSync(&d_stream);           /* but skip the damaged part */
404    CHECK_ERR(err, "inflateSync");
405
406    err = inflate(&d_stream, Z_FINISH);
407    if (err != Z_DATA_ERROR) {
408        fprintf(stderr, "inflate should report DATA_ERROR\n");
409        /* Because of incorrect adler32 */
410	exit(1);
411    }
412    err = inflateEnd(&d_stream);
413    CHECK_ERR(err, "inflateEnd");
414
415    printf("after inflateSync(): hel%s\n", (char *)uncompr);
416}
417
418/* ===========================================================================
419 * Test deflate() with preset dictionary
420 */
421void test_dict_deflate(compr, comprLen)
422    Byte *compr;
423    uLong comprLen;
424{
425    z_stream c_stream; /* compression stream */
426    int err;
427
428    c_stream.zalloc = (alloc_func)0;
429    c_stream.zfree = (free_func)0;
430    c_stream.opaque = (voidpf)0;
431
432    err = deflateInit(&c_stream, Z_BEST_COMPRESSION);
433    CHECK_ERR(err, "deflateInit");
434
435    err = deflateSetDictionary(&c_stream,
436			       (const Bytef*)dictionary, sizeof(dictionary));
437    CHECK_ERR(err, "deflateSetDictionary");
438
439    dictId = c_stream.adler;
440    c_stream.next_out = compr;
441    c_stream.avail_out = (uInt)comprLen;
442
443    c_stream.next_in = (Bytef*)hello;
444    c_stream.avail_in = (uInt)strlen(hello)+1;
445
446    err = deflate(&c_stream, Z_FINISH);
447    if (err != Z_STREAM_END) {
448        fprintf(stderr, "deflate should report Z_STREAM_END\n");
449	exit(1);
450    }
451    err = deflateEnd(&c_stream);
452    CHECK_ERR(err, "deflateEnd");
453}
454
455/* ===========================================================================
456 * Test inflate() with a preset dictionary
457 */
458void test_dict_inflate(compr, comprLen, uncompr, uncomprLen)
459    Byte *compr, *uncompr;
460    uLong comprLen, uncomprLen;
461{
462    int err;
463    z_stream d_stream; /* decompression stream */
464
465    strcpy((char*)uncompr, "garbage");
466
467    d_stream.zalloc = (alloc_func)0;
468    d_stream.zfree = (free_func)0;
469    d_stream.opaque = (voidpf)0;
470
471    d_stream.next_in  = compr;
472    d_stream.avail_in = (uInt)comprLen;
473
474    err = inflateInit(&d_stream);
475    CHECK_ERR(err, "inflateInit");
476
477    d_stream.next_out = uncompr;
478    d_stream.avail_out = (uInt)uncomprLen;
479
480    for (;;) {
481        err = inflate(&d_stream, Z_NO_FLUSH);
482        if (err == Z_STREAM_END) break;
483	if (err == Z_NEED_DICT) {
484	    if (d_stream.adler != dictId) {
485		fprintf(stderr, "unexpected dictionary");
486		exit(1);
487	    }
488	    err = inflateSetDictionary(&d_stream, (const Bytef*)dictionary,
489				       sizeof(dictionary));
490	}
491        CHECK_ERR(err, "inflate with dict");
492    }
493
494    err = inflateEnd(&d_stream);
495    CHECK_ERR(err, "inflateEnd");
496
497    if (strcmp((char*)uncompr, hello)) {
498        fprintf(stderr, "bad inflate with dict\n");
499	exit(1);
500    } else {
501        printf("inflate with dictionary: %s\n", (char *)uncompr);
502    }
503}
504
505/* ===========================================================================
506 * Usage:  example [output.gz  [input.gz]]
507 */
508
509int main(argc, argv)
510    int argc;
511    char *argv[];
512{
513    Byte *compr, *uncompr;
514    uLong comprLen = 10000*sizeof(int); /* don't overflow on MSDOS */
515    uLong uncomprLen = comprLen;
516    static const char* myVersion = ZLIB_VERSION;
517
518    if (zlibVersion()[0] != myVersion[0]) {
519        fprintf(stderr, "incompatible zlib version\n");
520        exit(1);
521
522    } else if (strcmp(zlibVersion(), ZLIB_VERSION) != 0) {
523        fprintf(stderr, "warning: different zlib version\n");
524    }
525
526    compr    = (Byte*)calloc((uInt)comprLen, 1);
527    uncompr  = (Byte*)calloc((uInt)uncomprLen, 1);
528    /* compr and uncompr are cleared to avoid reading uninitialized
529     * data and to ensure that uncompr compresses well.
530     */
531    if (compr == Z_NULL || uncompr == Z_NULL) {
532        printf("out of memory\n");
533	exit(1);
534    }
535    test_compress(compr, comprLen, uncompr, uncomprLen);
536
537    test_gzio((argc > 1 ? argv[1] : TESTFILE),
538              (argc > 2 ? argv[2] : TESTFILE),
539	      uncompr, (int)uncomprLen);
540
541    test_deflate(compr, comprLen);
542    test_inflate(compr, comprLen, uncompr, uncomprLen);
543
544    test_large_deflate(compr, comprLen, uncompr, uncomprLen);
545    test_large_inflate(compr, comprLen, uncompr, uncomprLen);
546
547    test_flush(compr, &comprLen);
548    test_sync(compr, comprLen, uncompr, uncomprLen);
549    comprLen = uncomprLen;
550
551    test_dict_deflate(compr, comprLen);
552    test_dict_inflate(compr, comprLen, uncompr, uncomprLen);
553
554    exit(0);
555    return 0; /* to avoid warning */
556}
557