From 5e09de40c3bce6d5fab191fd4364f2f6bbc29b60 Mon Sep 17 00:00:00 2001
From: Gleb Smirnoff <glebius@FreeBSD.org>
Date: Tue, 14 Feb 2006 11:08:05 +0000
Subject: [PATCH] Add '-F' option which allows to delete existing empty
 directories, when creating symbolic links.

PR:		bin/92149
Submitted by:	Eugene Grosbein <eugen grosbein.pp.ru>
---
 bin/ln/ln.1 | 30 +++++++++++++++++++++++++++---
 bin/ln/ln.c | 28 +++++++++++++++++++++++-----
 2 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/bin/ln/ln.1 b/bin/ln/ln.1
index e494d1465f7f..4c17dc153e20 100644
--- a/bin/ln/ln.1
+++ b/bin/ln/ln.1
@@ -32,7 +32,7 @@
 .\"	@(#)ln.1	8.2 (Berkeley) 12/30/93
 .\" $FreeBSD$
 .\"
-.Dd December 30, 1993
+.Dd February 14, 2006
 .Dt LN 1
 .Os
 .Sh NAME
@@ -41,11 +41,11 @@
 .Nd make links
 .Sh SYNOPSIS
 .Nm
-.Op Fl fhinsv
+.Op Fl Ffhinsv
 .Ar source_file
 .Op Ar target_file
 .Nm
-.Op Fl fhinsv
+.Op Fl Ffhinsv
 .Ar source_file ...
 .Ar target_dir
 .Nm link
@@ -76,6 +76,24 @@ then unlink it so that the link may occur.
 option overrides any previous
 .Fl i
 options.)
+.It Fl F
+If the target file already exists and is a directory, then remove it
+so that the link may occur.
+The
+.Fl F
+option should be used with either
+.Fl f
+or
+.Fl i
+options.
+If none is specified,
+.Fl f
+is implied.
+The
+.Fl F
+option is a no-op unless
+.Fl s
+option is specified.
 .It Fl h
 If the
 .Ar target_file
@@ -179,6 +197,12 @@ options are non-standard and their use in scripts is not recommended.
 They are provided solely for compatibility with other
 .Nm
 implementations.
+.Pp
+The
+.Fl F
+option is
+.Fx
+extention and should not be used in portable scripts.
 .Sh SEE ALSO
 .Xr link 2 ,
 .Xr lstat 2 ,
diff --git a/bin/ln/ln.c b/bin/ln/ln.c
index 5609449a4d69..76c743ee4a81 100644
--- a/bin/ln/ln.c
+++ b/bin/ln/ln.c
@@ -53,6 +53,7 @@ __FBSDID("$FreeBSD$");
 #include <unistd.h>
 
 int	fflag;				/* Unlink existing files. */
+int	Fflag;				/* Remove empty directories also. */
 int	hflag;				/* Check new name for symlink first. */
 int	iflag;				/* Interactive mode. */
 int	sflag;				/* Symbolic, not hard, link. */
@@ -91,8 +92,11 @@ main(int argc, char *argv[])
 		exit(linkit(argv[0], argv[1], 0));
 	}
 
-	while ((ch = getopt(argc, argv, "fhinsv")) != -1)
+	while ((ch = getopt(argc, argv, "Ffhinsv")) != -1)
 		switch (ch) {
+		case 'F':
+			Fflag = 1;
+			break;
 		case 'f':
 			fflag = 1;
 			iflag = 0;
@@ -121,6 +125,10 @@ main(int argc, char *argv[])
 
 	linkf = sflag ? symlink : link;
 	linkch = sflag ? '-' : '=';
+	if (sflag == 0)
+		Fflag = 0;
+	if (Fflag == 1 && iflag == 0)
+		fflag = 1;
 
 	switch(argc) {
 	case 0:
@@ -200,7 +208,12 @@ linkit(const char *target, const char *source, int isdir)
 	 * and interactively if -i was specified.
 	 */
 	if (fflag && exists) {
-		if (unlink(source)) {
+		if (Fflag && S_ISDIR(sb.st_mode)) {
+			if (rmdir(source)) {
+				warn("%s", source);
+				return (1);
+			}
+		} else if (unlink(source)) {
 			warn("%s", source);
 			return (1);
 		}
@@ -216,7 +229,12 @@ linkit(const char *target, const char *source, int isdir)
 			return (1);
 		}
 
-		if (unlink(source)) {
+		if (Fflag && S_ISDIR(sb.st_mode)) {
+			if (rmdir(source)) {
+				warn("%s", source);
+				return (1);
+			}
+		} else if (unlink(source)) {
 			warn("%s", source);
 			return (1);
 		}
@@ -236,8 +254,8 @@ void
 usage(void)
 {
 	(void)fprintf(stderr, "%s\n%s\n%s\n",
-	    "usage: ln [-fhinsv] source_file [target_file]",
-	    "       ln [-fhinsv] source_file ... target_dir",
+	    "usage: ln [-Ffhinsv] source_file [target_file]",
+	    "       ln [-Ffhinsv] source_file ... target_dir",
 	    "       link source_file target_file");
 	exit(1);
 }