zlib 0.71

minigzip.c

@@ -0,0 +1,210 @@
+/* minigzip.c -- simulate gzip using the zlib compression library
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/*
+ * minigzip is a minimal implementation of the gzip utility. This is
+ * only an example of using zlib and isn't meant to replace the
+ * full-featured gzip. No attempt is made to deal with file systems
+ * limiting names to 14 or 8+3 characters, etc... Error checking is
+ * very limited. So use minigzip only for testing; use gzip for the
+ * real thing. On MSDOS, use only on file names without extension
+ * or in pipe mode.
+ */
+
+/* $Id: minigzip.c,v 1.1 1995/04/14 13:35:59 jloup Exp $ */
+
+#include <stdio.h>
+#include "zlib.h"
+
+#ifdef MSDOS
+#  include <fcntl.h>
+#  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
+#else
+#  define SET_BINARY_MODE(file)
+#endif
+
+#define BUFLEN 4096
+#define MAX_NAME_LEN 1024
+
+#define local static
+/* For MSDOS and other systems with limitation on stack size. For Unix,
+    #define local
+   works also.
+ */
+
+char *prog;
+
+/* ===========================================================================
+ * Display error message and exit
+ */
+void error(msg)
+    char *msg;
+{
+    fprintf(stderr, "%s: %s\n", prog, msg);
+    exit(1);
+}
+
+/* ===========================================================================
+ * Compress input to output then close both files.
+ */
+void gz_compress(in, out)
+    FILE   *in;
+    gzFile out;
+{
+    local char buf[BUFLEN];
+    int len;
+    int err;
+
+    for (;;) {
+	len = fread(buf, 1, sizeof(buf), in);
+	if (ferror(in)) {
+	    perror("fread");
+	    exit(1);
+	}
+	if (len == 0) break;
+
+	if (gzwrite(out, buf, len) != len) error(gzerror(out, &err));
+    }
+    fclose(in);
+    if (gzclose(out) != Z_OK) error("failed gzclose");
+}
+
+/* ===========================================================================
+ * Uncompress input to output then close both files.
+ */
+void gz_uncompress(in, out)
+    gzFile in;
+    FILE   *out;
+{
+    local char buf[BUFLEN];
+    int len;
+    int err;
+
+    for (;;) {
+	len = gzread(in, buf, sizeof(buf));
+	if (len < 0) error (gzerror(in, &err));
+	if (len == 0) break;
+
+	if (fwrite(buf, 1, len, out) != len) error("failed fwrite");
+    }
+    if (fclose(out)) error("failed fclose");
+
+    if (gzclose(in) != Z_OK) error("failed gzclose");
+}
+
+
+/* ===========================================================================
+ * Compress the given file: create a corresponding .gz file and remove the
+ * original.
+ */
+void file_compress(file)
+    char  *file;
+{
+    local char outfile[MAX_NAME_LEN];
+    FILE  *in;
+    gzFile out;
+
+    strcpy(outfile, file);
+    strcat(outfile, ".gz");
+
+    in = fopen(file, "rb");
+    if (in == NULL) {
+	perror(file);
+	exit(1);
+    }
+    out = gzopen(outfile, "wb");
+    if (out == NULL) {
+	fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
+	exit(1);
+    }
+    gz_compress(in, out);
+
+    unlink(file);
+}
+
+
+/* ===========================================================================
+ * Uncompress the given file and remove the original.
+ */
+void file_uncompress(file)
+    char  *file;
+{
+    local char buf[MAX_NAME_LEN];
+    char *infile, *outfile;
+    FILE  *out;
+    gzFile in;
+    int len = strlen(file);
+
+    strcpy(buf, file);
+
+    if (len > 3 && strcmp(file+len-3, ".gz") == 0) {
+	infile = file;
+	outfile = buf;
+	outfile[len-3] = '\0';
+    } else {
+	outfile = file;
+	infile = buf;
+	strcat(infile, ".gz");
+    }
+    in = gzopen(infile, "rb");
+    if (in == NULL) {
+	fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
+	exit(1);
+    }
+    out = fopen(outfile, "wb");
+    if (out == NULL) {
+	perror(file);
+	exit(1);
+    }
+
+    gz_uncompress(in, out);
+
+    unlink(infile);
+}
+
+
+/* ===========================================================================
+ * Usage:  minigzip [-d] [files...]
+ */
+
+void main(argc, argv)
+    int argc;
+    char *argv[];
+{
+    int uncompr = 0;
+    gzFile file;
+
+    prog = argv[0];
+    argc--, argv++;
+
+    if (argc > 0) {
+	uncompr = (strcmp(*argv, "-d") == 0);
+	if (uncompr) {
+	    argc--, argv++;
+	}
+    }
+    if (argc == 0) {
+        SET_BINARY_MODE(stdin);
+        SET_BINARY_MODE(stdout);
+	if (uncompr) {
+	    file = gzdopen(fileno(stdin), "rb");
+            if (file == NULL) error("can't gzdopen stdin");
+	    gz_uncompress(file, stdout);
+	} else {
+	    file = gzdopen(fileno(stdout), "wb");
+            if (file == NULL) error("can't gzdopen stdout");
+	    gz_compress(stdin, file);
+	}
+    } else {
+	do {
+	    if (uncompr) {
+		file_uncompress(*argv);
+	    } else {
+		file_compress(*argv);
+	    }
+	} while (argv++, --argc);
+    }
+    exit(0);
+}