ln: add -L/-P options

* src/ln.c (STAT_LIKE_LINK): Delete.
(logical): New flag.
(long_options): Add -L, -P.
(usage): Mention them.
(main): Choose between them.
(do_link): Perform correct action.
* tests/ln/misc: Move hard-to-sym portion of test...
* tests/ln/hard-to-sym: ...into new test, and add more.
* tests/Makefile.am (TESTS): Run new test.
* NEWS: Document this.
* doc/coreutils.texi (link invocation, ln invocation): Likewise.
* bootstrap.conf (gnulib_modules): Add linkat.

2 files changed, 82 insertions, 23 deletions

diff --git a/tests/ln/hard-to-sym b/tests/ln/hard-to-sym
new file mode 100755
index 000000000..510b57abf
--- /dev/null
+++ b/tests/ln/hard-to-sym
@@ -0,0 +1,82 @@
+#!/bin/sh
+# Tests for ln -L/-P.
+
+# Copyright (C) 2009 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  ln --version
+fi
+
+. $srcdir/test-lib.sh
+
+fail=0
+
+# ===================================================
+# ensure -s silently overrides -L, -P
+touch a || framework_failure
+ln -L -s a symlink1 || fail=1
+ln -P -s symlink1 symlink2 || fail=1
+ln -s -L -P symlink2 symlink3 || fail=1
+
+# ===================================================
+# ensure that -L follows symlinks, and overrides -P
+ln -P -L symlink3 hard-to-a || fail=1
+ls=`ls -lG hard-to-a`x
+case "$ls" in
+  *'hard-to-ax') ;;
+  *'hard-to-a -> '*x) fail=1 ;;
+  *) framework_failure ;;
+esac
+
+# ===================================================
+# ensure that -P links (or at least duplicates) symlinks, and overrides -L
+ln -L -P symlink3 hard-to-3 || fail=1
+ls=`ls -lG hard-to-3`x
+case "$ls" in
+  *'hard-to-3 -> symlink2x') ;;
+  *'hard-to-3x') fail=1 ;;
+  *'hard-to-3 -> '*x) fail=1 ;;
+  *) framework_failure ;;
+esac
+
+# ===================================================
+# Create a hard link to a dangling symlink.
+ln -s /no-such-dir || framework_failure
+ln -L no-such-dir hard-to-dangle 2>err && fail=1
+case `cat err` in
+  *' accessing `no-such-dir'\':*) ;;
+  *) fail=1 ;;
+esac
+ln -P no-such-dir hard-to-dangle || fail=1
+
+# ===================================================
+# Create a hard link to a symlink to a directory.
+mkdir d || framework_failure
+ln -s d link-to-dir || framework_failure
+ln -L link-to-dir hard-to-dir-link 2>err && fail=1
+case `cat err` in
+  *': `link-to-dir'\'': hard link not allowed for directory'*) ;;
+  *) fail=1 ;;
+esac
+ln -P link-to-dir/ hard-to-dir-link 2>err && fail=1
+case `cat err` in
+  *': `link-to-dir/'\'': hard link not allowed for directory'*) ;;
+  *) fail=1 ;;
+esac
+ln -P link-to-dir hard-to-dir-link || fail=1
+
+Exit $fail
diff --git a/tests/ln/misc b/tests/ln/misc
index f13bd7bf3..d42d68a27 100755
--- a/tests/ln/misc
+++ b/tests/ln/misc
@@ -108,29 +108,6 @@ ln b b~ || framework_failure
 ln -f --b=simple a b || fail=1
 
 # ===================================================
-# determine if link(2) follows symlinks on this system
-touch a || framework_failure
-ln -s a symlink || framework_failure
-ln symlink hard-to-sym > /dev/null 2>&1 || framework_failure
-ls=`ls -lG hard-to-sym`x
-case "$ls" in
-  *'hard-to-symx') link_follows_symlink=yes ;;
-  *'hard-to-sym -> ax') link_follows_symlink=no ;;
-  *) framework_failure ;;
-esac
-
-if test $link_follows_symlink = no; then
-  # Create a hard link to a dangling symlink.
-  # This is not portable.  At least sunos4.1.4 and OpenBSD 2.3 fail this test.
-  # They get this:
-  # ln: cannot create hard link `hard-to-dangle' to `no-such-dir': \
-  #   No such file or directory
-  #
-  ln -s /no-such-dir || fail=1
-  ln no-such-dir hard-to-dangle > /dev/null 2>&1 || fail=1
-fi
-rm -rf a symlink hard-to-sym hard-to-dangle
-# ===================================================
 
 # Make sure ln can make simple backups.
 # This was fixed in 4.0.34.  Broken in 4.0r.