1 files changed, 201 insertions, 0 deletions

diff --git a/example.c b/example.c
new file mode 100644
index 0000000..ea1a9eb
--- /dev/null
+++ b/example.c
@@ -0,0 +1,201 @@
+/* example.c -- usage example of the zlib compression library
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* $Id: example.c,v 1.4 1995/04/14 13:32:49 jloup Exp $ */
+
+#include <stdio.h>
+#include "zlib.h"
+
+#define BUFLEN 4096
+
+#define local static
+/* For MSDOS and other systems with limitation on stack size. For Unix,
+    #define local
+   works also.
+ */
+
+#define CHECK_ERR(err, msg) { \
+    if (err != Z_OK) { \
+        fprintf(stderr, "%s error: %d\n", msg, err); \
+        exit(1); \
+    } \
+}
+
+char *hello = "hello world";
+
+/* ===========================================================================
+ * Test compress() and uncompress()
+ */
+void test_compress()
+{
+    local Byte compr[BUFLEN];
+    uLong comprLen = sizeof(compr);
+    local Byte uncompr[BUFLEN];
+    uLong uncomprLen = sizeof(uncompr);
+    int err;
+    uLong len = strlen(hello)+1;
+
+    err = compress(compr, &comprLen, hello, len);
+    CHECK_ERR(err, "compress");
+
+    strcpy(uncompr, "garbage");
+
+    err = uncompress(uncompr, &uncomprLen, compr, comprLen);
+    CHECK_ERR(err, "uncompress");
+
+    if (strcmp(uncompr, hello)) {
+        fprintf(stderr, "bad uncompress\n");
+    } else {
+        printf("uncompress(): %s\n", uncompr);
+    }
+}
+
+/* ===========================================================================
+ * Test read/write of .gz files
+ */
+void test_gzio(out, in)
+    char *out; /* output file */
+    char *in;  /* input file */
+{
+    local Byte uncompr[BUFLEN];
+    uLong uncomprLen = sizeof(uncompr);
+    int err;
+    int len = strlen(hello)+1;
+    gzFile file;
+
+    file = gzopen(out, "wb");
+    if (file == NULL) {
+        fprintf(stderr, "gzopen error\n");
+        exit(1);
+    }
+
+    if (gzwrite(file, hello, len) != len) {
+        fprintf(stderr, "gzwrite err: %s\n", gzerror(file, &err));
+    }
+    gzclose(file);
+
+    file = gzopen(in, "rb");
+    if (file == NULL) {
+        fprintf(stderr, "gzopen error\n");
+    }
+    strcpy(uncompr, "garbage");
+
+    uncomprLen = gzread(file, uncompr, uncomprLen);
+    if (uncomprLen != len) {
+        fprintf(stderr, "gzread err: %s\n", gzerror(file, &err));
+    }
+    gzclose(file);
+
+    if (strcmp(uncompr, hello)) {
+        fprintf(stderr, "bad gzread\n");
+    } else {
+        printf("gzread(): %s\n", uncompr);
+    }
+}
+
+/* ===========================================================================
+ * Test deflate() with small buffers, return the compressed length.
+ */
+uLong test_deflate(compr)
+    Byte compr[];
+{
+    z_stream c_stream; /* compression stream */
+    int err;
+    int len = strlen(hello)+1;
+
+    c_stream.zalloc = (alloc_func)0;
+    c_stream.zfree = (free_func)0;
+
+    err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
+    CHECK_ERR(err, "deflateInit");
+
+    c_stream.next_in  = (Byte*)hello;
+    c_stream.next_out = compr;
+
+    while (c_stream.total_in != len) {
+        c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
+        err = deflate(&c_stream, Z_NO_FLUSH);
+        CHECK_ERR(err, "deflate");
+    }
+    /* Finish the stream, still forcing small buffers: */
+    do {
+        c_stream.avail_out = 1;
+        err = deflate(&c_stream, Z_FINISH);
+        CHECK_ERR(err, "deflate");
+    } while (c_stream.avail_out == 0);
+
+    err = deflateEnd(&c_stream);
+    CHECK_ERR(err, "deflateEnd");
+
+    return c_stream.total_out;
+}
+
+/* ===========================================================================
+ * Test inflate() with small buffers
+ */
+void test_inflate(compr)
+    Byte compr[];
+{
+    local Byte uncompr[BUFLEN];
+    int err;
+    z_stream d_stream; /* decompression stream */
+
+    strcpy(uncompr, "garbage");
+
+    d_stream.zalloc = (alloc_func)0;
+    d_stream.zfree = (free_func)0;
+
+    err = inflateInit(&d_stream);
+    CHECK_ERR(err, "inflateInit");
+
+    d_stream.next_in  = compr;
+    d_stream.next_out = uncompr;
+
+    for (;;) {
+        d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
+        err = inflate(&d_stream, Z_NO_FLUSH);
+        if (err == Z_STREAM_END) break;
+        CHECK_ERR(err, "inflate");
+    }
+
+    err = inflateEnd(&d_stream);
+    CHECK_ERR(err, "inflateEnd");
+
+    if (strcmp(uncompr, hello)) {
+        fprintf(stderr, "bad inflate\n");
+    } else {
+        printf("inflate(): %s\n", uncompr);
+    }
+}
+
+/* ===========================================================================
+ * Usage:  example [output.gz  [input.gz]]
+ */
+
+void main(argc, argv)
+    int argc;
+    char *argv[];
+{
+    local Byte compr[BUFLEN];
+    uLong comprLen;
+
+    if (zlib_version[0] != ZLIB_VERSION[0]) {
+        fprintf(stderr, "incompatible zlib version\n");
+        exit(1);
+
+    } else if (strcmp(zlib_version, ZLIB_VERSION) != 0) {
+        fprintf(stderr, "warning: different zlib version\n");
+    }
+    test_compress();
+
+    test_gzio((argc > 1 ? argv[1] : "foo.gz"),
+              (argc > 2 ? argv[2] : "foo.gz"));
+
+    comprLen = test_deflate(compr);
+
+    test_inflate(compr);
+
+    exit(0);
+}