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authorTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
committerTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
commitd6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch)
treeece253b876159b39c620e62b6c9b1174642e070e /usr.bin/file/compress.c
initial import of NetBSD tree
Diffstat (limited to 'usr.bin/file/compress.c')
-rw-r--r--usr.bin/file/compress.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/usr.bin/file/compress.c b/usr.bin/file/compress.c
new file mode 100644
index 00000000000..6e2c336cd10
--- /dev/null
+++ b/usr.bin/file/compress.c
@@ -0,0 +1,122 @@
+/*
+ * 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
+ * $Id: compress.c,v 1.1 1995/10/18 08:45:08 deraadt Exp $
+ */
+#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;
+ }
+}