X-Git-Url: https://git.saurik.com/apple/file_cmds.git/blobdiff_plain/fc155071fbbd3dce883ee597b09ca00b6a85119e..440bd1982b8e55068af44543d97888092d61feee:/file/compress.c?ds=sidebyside

diff --git a/file/compress.c b/file/compress.c
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+++ b/file/compress.c
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+/*
+ * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
+ * Reserved.  This file contains Original Code and/or Modifications of
+ * Original Code as defined in and that are subject to the Apple Public
+ * Source License Version 1.1 (the "License").  You may not use this file
+ * except in compliance with the License.  Please obtain a copy of the
+ * License at http://www.apple.com/publicsource and read it before using
+ * this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+/*	$OpenBSD: compress.c,v 1.3 1997/02/09 23:58:19 millert Exp $	*/
+
+/*
+ * compress routines:
+ *	zmagic() - returns 0 if not recognized, uncompresses and prints
+ *		   information if recognized
+ *	uncompress(method, old, n, newch) - uncompress old into new, 
+ *					    using method, return sizeof new
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include "file.h"
+
+static struct {
+   char *magic;
+   int   maglen;
+   char *argv[3];
+   int	 silent;
+} compr[] = {
+    { "\037\235", 2, { "uncompress", "-c", NULL }, 0 },	/* compressed */
+    { "\037\213", 2, { "gzip", "-cdq", NULL }, 1 },	/* gzipped */
+    { "\037\236", 2, { "gzip", "-cdq", NULL }, 1 },	/* frozen */
+    { "\037\240", 2, { "gzip", "-cdq", NULL }, 1 },	/* SCO LZH */
+    /* the standard pack utilities do not accept standard input */
+    { "\037\036", 2, { "gzip", "-cdq", NULL }, 0 },	/* packed */
+};
+
+static int ncompr = sizeof(compr) / sizeof(compr[0]);
+
+
+static int uncompress __P((int, const unsigned char *, unsigned char **, int));
+
+int
+zmagic(buf, nbytes)
+unsigned char *buf;
+int nbytes;
+{
+	unsigned char *newbuf;
+	int newsize;
+	int i;
+
+	for (i = 0; i < ncompr; i++) {
+		if (nbytes < compr[i].maglen)
+			continue;
+		if (memcmp(buf, compr[i].magic,  compr[i].maglen) == 0)
+			break;
+	}
+
+	if (i == ncompr)
+		return 0;
+
+	if ((newsize = uncompress(i, buf, &newbuf, nbytes)) != 0) {
+		tryit(newbuf, newsize, 1);
+		free(newbuf);
+		printf(" (");
+		tryit(buf, nbytes, 0);
+		printf(")");
+	}
+	return 1;
+}
+
+
+static int
+uncompress(method, old, newch, n)
+int method;
+const unsigned char *old;
+unsigned char **newch;
+int n;
+{
+	int fdin[2], fdout[2];
+
+	if (pipe(fdin) == -1 || pipe(fdout) == -1) {
+		error("cannot create pipe (%s).\n", strerror(errno));	
+		/*NOTREACHED*/
+	}
+	switch (fork()) {
+	case 0:	/* child */
+		(void) close(0);
+		(void) dup(fdin[0]);
+		(void) close(fdin[0]);
+		(void) close(fdin[1]);
+
+		(void) close(1);
+		(void) dup(fdout[1]);
+		(void) close(fdout[0]);
+		(void) close(fdout[1]);
+		if (compr[method].silent)
+		    (void) close(2);
+
+		execvp(compr[method].argv[0], compr[method].argv);
+		error("could not execute `%s' (%s).\n", 
+		      compr[method].argv[0], strerror(errno));
+		/*NOTREACHED*/
+	case -1:
+		error("could not fork (%s).\n", strerror(errno));
+		/*NOTREACHED*/
+
+	default: /* parent */
+		(void) close(fdin[0]);
+		(void) close(fdout[1]);
+		if (write(fdin[1], old, n) != n) {
+			error("write failed (%s).\n", strerror(errno));
+			/*NOTREACHED*/
+		}
+		(void) close(fdin[1]);
+		if ((*newch = (unsigned char *) malloc(n)) == NULL) {
+			error("out of memory.\n");
+			/*NOTREACHED*/
+		}
+		if ((n = read(fdout[0], *newch, n)) <= 0) {
+			free(*newch);
+			error("read failed (%s).\n", strerror(errno));
+			/*NOTREACHED*/
+		}
+		(void) close(fdout[0]);
+		(void) wait(NULL);
+		return n;
+	}
+}