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, 3 deletions

diff --git a/bin/ln/ln.c b/bin/ln/ln.c
index 48dbeae..dc2db0f 100644
--- a/bin/ln/ln.c
+++ b/bin/ln/ln.c
@@ -73,7 +73,24 @@ main(argc, argv)
 	extern int optind;
 	struct stat sb;
 	int ch, exitval;
-	char *sourcedir;
+	char *p, *sourcedir;
+
+	/*
+	 * Test for the special case where the utility is called as
+	 * "link", for which the functionality provided is greatly
+	 * simplified.
+	 */
+	if ((p = rindex(argv[0], '/')) == NULL)
+		p = argv[0];
+	else
+		++p;
+	if (strcmp(p, "link") == 0) {
+		if (argc == 3) {
+			linkf = link;
+			exit(linkit(argv[1], argv[2], 0));
+		} else
+			usage();
+	}
 
 	while ((ch = getopt(argc, argv, "fsv")) != -1)
 		switch (ch) {
@@ -167,8 +184,9 @@ linkit(target, source, isdir)
 void
 usage()
 {
-	(void)fprintf(stderr, "%s\n%s\n",
+	(void)fprintf(stderr, "%s\n%s\n%s\n",
 	    "usage: ln [-fsv] file1 file2",
-	    "       ln [-fsv] file ... directory");
+	    "       ln [-fsv] file ... directory",
+	    "       link file1 file2");
 	exit(1);
 }