Command-line utility to compress to DEFLATE using zlib.

deflater.c

@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <zlib.h>
+
+#define IN_SIZE_MAX 60000
+#define OUT_SIZE_MAX 60000
+
+int main(int argc, char* argv[])
+{
+	FILE* fp;
+	char* inbuf;
+	char* outbuf;
+	size_t inlen;
+	size_t outlen;
+	z_stream stream;
+
+	/* check command line */
+	if (argc != 3) {
+		fprintf(stderr,
+			"Compresses a file to DEFLATE format.\n"
+			"24-08-2002, fox@scene.pl\n"
+			"Usage: deflater input_file deflated_file\n"
+		);
+		return 3;
+	}
+
+	/* alloc buffers */
+	inbuf = malloc(IN_SIZE_MAX);
+	outbuf = malloc(OUT_SIZE_MAX);
+	if (inbuf == NULL || outbuf == NULL) {
+		fprintf(stderr, "deflater: Out of memory!\n");
+		return 1;
+	}
+
+	/* read input file */
+	fp = fopen(argv[1], "rb");
+	if (fp == NULL) {
+		perror(argv[1]);
+		return 1;
+	}
+	inlen = fread(inbuf, 1, IN_SIZE_MAX, fp);
+	fclose(fp);
+
+	/* compress */
+	stream.next_in = inbuf;
+	stream.avail_in = inlen;
+	stream.next_out = outbuf;
+	stream.avail_out = OUT_SIZE_MAX;
+	stream.zalloc = (alloc_func) 0;
+	stream.zfree = (free_func) 0;
+	if (deflateInit2(&stream, Z_BEST_COMPRESSION, Z_DEFLATED,
+		-MAX_WBITS, 9, Z_DEFAULT_STRATEGY) != Z_OK) {
+		fprintf(stderr, "deflater: deflateInit2 failed\n");
+		return 1;
+	}
+	if (deflate(&stream, Z_FINISH) != Z_STREAM_END) {
+		fprintf(stderr, "deflater: deflate failed\n");
+		return 1;
+	}
+	if (deflateEnd(&stream) != Z_OK) {
+		fprintf(stderr, "deflater: deflateEnd failed\n");
+		return 1;
+	}
+
+	/* write output */
+	fp = fopen(argv[2], "wb");
+	if (fp == NULL) {
+		perror(argv[2]);
+		return 1;
+	}
+	outlen = fwrite(outbuf, 1, stream.total_out, fp);
+	fclose(fp);
+	if (outlen != stream.total_out) {
+		perror(argv[2]);
+		return 1;
+	}
+
+	/* display summary */
+	printf("Compressed %s (%d bytes) to %s (%d bytes)\n",
+		argv[1], inlen, argv[2], outlen);
+	return 0;
+}