Add a -h option to tell cmp not to follow symbolic links.

MFC after:	3 weeks
Sponsored by:	Sophos/ActiveState

1 files changed, 93 insertions, 0 deletions

diff --git a/usr.bin/cmp/link.c b/usr.bin/cmp/link.c
new file mode 100644
index 0000000..fe45def
--- /dev/null
+++ b/usr.bin/cmp/link.c
@@ -0,0 +1,93 @@
+/*-
+ * Copyright (c) 2005 Brian Somers <brian@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <err.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "extern.h"
+
+void
+c_link(const char *file1, off_t skip1, const char *file2, off_t skip2)
+{
+	char buf1[PATH_MAX], *p1;
+	char buf2[PATH_MAX], *p2;
+	int dfound, len1, len2;
+	off_t byte;
+	u_char ch;
+
+	if ((len1 = readlink(file1, buf1, sizeof(buf1) - 1)) < 0) {
+		if (!sflag)
+			err(ERR_EXIT, "%s", file1);
+		else
+			exit(ERR_EXIT);
+	}
+
+	if ((len2 = readlink(file2, buf2, sizeof(buf2) - 1)) < 0) {
+		if (!sflag)
+			err(ERR_EXIT, "%s", file2);
+		else
+			exit(ERR_EXIT);
+	}
+
+	if (skip1 > len1)
+		skip1 = len1;
+	buf1[len1] = '\0';
+
+	if (skip2 > len2)
+		skip2 = len2;
+	buf2[len2] = '\0';
+
+	dfound = 0;
+	byte = 1;
+	for (p1 = buf1 + skip1, p2 = buf2 + skip2; *p1 && *p2; p1++, p2++) {
+		if ((ch = *p1) != *p2) {
+			if (xflag) {
+				dfound = 1;
+				(void)printf("%08llx %02x %02x\n",
+				    (long long)byte - 1, ch, *p2);
+			} else if (lflag) {
+				dfound = 1;
+				(void)printf("%6lld %3o %3o\n",
+				    (long long)byte, ch, *p2);
+			} else
+				diffmsg(file1, file2, byte, 1);
+				/* NOTREACHED */
+		}
+		byte++;
+	}
+
+	if (*p1 || *p2)
+		eofmsg (*p1 ? file2 : file1);
+	if (dfound)
+		exit(DIFF_EXIT);
+}