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+/* zpipe.c: example of proper use of zlib's inflate() and deflate()
+ Not copyrighted -- provided to the public domain
+ Version 1.4 11 December 2005 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
+ 1.3 6 Apr 2005 Remove incorrect assertion in inf()
+ 1.4 11 Dec 2005 Add hack to avoid MSDOS end-of-line conversions
+ Avoid some compiler warnings for input and output buffers
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include "zlib.h"
+
+#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
+# include <fcntl.h>
+# include <io.h>
+# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+# define SET_BINARY_MODE(file)
+#endif
+
+#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;
+ unsigned char in[CHUNK];
+ unsigned 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;
+ unsigned char in[CHUNK];
+ unsigned 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);
+
+ /* 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);
+ }
+}
+
+/* compress or decompress from stdin to stdout */
+int main(int argc, char **argv)
+{
+ int ret;
+
+ /* avoid end-of-line conversions */
+ SET_BINARY_MODE(stdin);
+ SET_BINARY_MODE(stdout);
+
+ /* do compression if no arguments */
+ if (argc == 1) {
+ ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
+ if (ret != Z_OK)
+ zerr(ret);
+ return ret;
+ }
+
+ /* do decompression if -d specified */
+ else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
+ ret = inf(stdin, stdout);
+ if (ret != Z_OK)
+ zerr(ret);
+ return ret;
+ }
+
+ /* otherwise, report usage */
+ else {
+ fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr);
+ return 1;
+ }
+}