maint: refactor relpath() from `realpath` for use by `ln`

* src/relpath.c: Refactored from realpath.c and adjusted
to support returning the relative path rather than just
printing to stdout.
* src/relpath.h: Export the relpath function.
* src/Makefile.am: Reference the refactored relpath module.
* po/POTFILES.in: Likewise.
* src/realpath.c: Adjust to the refactored relpath module.

1 files changed, 25 insertions, 0 deletions

diff --git a/src/relpath.h b/src/relpath.h
new file mode 100644
index 000000000..e25f82b22
--- /dev/null
+++ b/src/relpath.h
@@ -0,0 +1,25 @@
+/* relpath - print the relative path
+   Copyright (C) 2012 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/>.  */
+
+/* Written by Pádraig Brady.  */
+
+#ifndef _RELPATH_H
+# define _RELPATH_H
+
+extern bool
+relpath (const char *can_fname, const char *can_reldir, char *buf, size_t len);
+
+#endif