mkfifo: new module

Solaris 9 mkfifo("name/",mode) mistakenly creates "name".
FreeBSD 7.2 mkfifo("dangling/",mode) mistakenly creates a fifo
at the target of "dangling".  Mingw lacks named pipes altogether,
but this at least avoids link failures.

* modules/mkfifo: New file.
* m4/mkfifo.m4 (gl_FUNC_MKFIFO): Likewise.
* lib/mkfifo.c (mkfifo): Likewise.
* m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Set witness
defaults.
* modules/sys_stat (Makefile.am): Substitute them.
* lib/sys_stat.in.h (mkfifo): Declare replacement.
* MODULES.html.sh (Support for systems lacking POSIX:2008):
Document it.
* doc/posix-functions/mkfifo.texi (mkfifo): Likewise.
* modules/mkfifo-tests: New test.
* tests/test-mkfifo.h (test_mkfifo): New file, borrowed in part
from test-mkfifoat.c.
* tests/test-mkfifo.c: New file.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 58 insertions, 0 deletions

diff --git a/lib/mkfifo.c b/lib/mkfifo.c
new file mode 100644
index 0000000000..3c29e8f6b6
--- /dev/null
+++ b/lib/mkfifo.c
@@ -0,0 +1,58 @@
+/* Create a named fifo.
+   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/>.  */
+
+/* written by Eric Blake */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <string.h>
+
+#if !HAVE_MKFIFO
+/* Mingw lacks mkfifo; always fail with ENOSYS.  */
+
+int
+mkfifo (char const *name _UNUSED_PARAMETER_, mode_t mode _UNUSED_PARAMETER_)
+{
+  errno = ENOSYS;
+  return -1;
+}
+
+#else /* HAVE_MKFIFO */
+
+# undef mkfifo
+
+/* Create a named fifo FILE, with access permissions in MODE.  Work
+around trailing slash bugs.  */
+
+int
+rpl_mkfifo (char const *name, mode_t mode)
+{
+# if MKFIFO_TRAILING_SLASH_BUG
+  size_t len = strlen (name);
+  if (len && name[len - 1] == '/')
+    {
+      struct stat st;
+      if (stat (name, &st) == 0)
+        errno = EEXIST;
+      return -1;
+    }
+# endif
+  return mkfifo (name, mode);
+}
+#endif /* HAVE_MKFIFO */