Add link(1) and unlink(1) as special cases of ln(1) and rm(1)

respectively, in accordance with SUSv2.

This differs from the approach taken in NetBSD, but provides
less obscure error messages in at least the EISDIR case and
does not take up additional disk space for new binaries.

PR:		13071
PR:		13074
Requested by:	James Howard <howardjp@wam.umd.edu>

1 files changed, 21 insertions, 1 deletions

diff --git a/bin/rm/rm.c b/bin/rm/rm.c
index 7d7de4b..a4a3c96 100644
--- a/bin/rm/rm.c
+++ b/bin/rm/rm.c
@@ -86,6 +86,24 @@ main(argc, argv)
 	char *argv[];
 {
 	int ch, rflag;
+	char *p;
+
+	/*
+	 * Test for the special case where the utility is called as
+	 * "unlink", for which the functionality provided is greatly
+	 * simplified.
+	 */
+	if ((p = rindex(argv[0], '/')) == NULL)
+		p = argv[0];
+	else
+		++p;
+	if (strcmp(p, "unlink") == 0) {
+		if (argc == 2) {
+			rm_file(&argv[1]);
+			exit(eval);
+		} else 
+			usage();
+	}
 
 	Pflag = rflag = 0;
 	while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
@@ -472,6 +490,8 @@ void
 usage()
 {
 
-	(void)fprintf(stderr, "usage: rm [-f | -i] [-dPRrvW] file ...\n");
+	(void)fprintf(stderr, "%s\n%s\n",
+	    "usage: rm [-f | -i] [-dPRrvW] file ...",
+	    "       unlink file");
 	exit(EX_USAGE);
 }