1 files changed, 91 insertions, 0 deletions
diff --git a/sysdeps/posix/ttyname_r.c b/sysdeps/posix/ttyname_r.c
new file mode 100644
index 0000000000..e225da2be2
--- /dev/null
+++ b/sysdeps/posix/ttyname_r.c
@@ -0,0 +1,91 @@
+/* Copyright (C) 1991, 1992, 1993, 1995 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+
+#ifndef MIN
+# define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+/* Store at most BUFLEN character of the pathname of the terminal FD is
+   open on in BUF.  Return 0 on success, -1 otherwise.  */
+int
+ttyname_r (fd, buf, buflen)
+     int fd;
+     char *buf;
+     int buflen;
+{
+  static const char dev[] = "/dev";
+  struct stat st;
+  dev_t mydev;
+  ino_t myino;
+  DIR *dirstream;
+  struct dirent *d;
+  int save = errno;
+
+  /* Test for the absolute minimal size.  This makes life easier inside
+     the loop.  */
+  if (buflen < sizeof (dev) + 2)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  if (fstat (fd, &st) < 0)
+    return -1;
+  mydev = st.st_dev;
+  myino = st.st_ino;
+
+  dirstream = opendir (dev);
+  if (dirstream == NULL)
+    return -1;
+
+  /* Prepare the result buffer.  */
+  memcpy (buf, dev, sizeof (dev));
+  buf[sizeof (dev)] = '/';
+  buflen -= sizeof (dev) + 1;
+
+  while ((d = readdir (dirstream)) != NULL)
+    if (d->d_fileno == myino)
+      {
+	char *cp;
+
+	cp = stpncpy (&buf[sizeof (dev) + 1], d->d_name,
+		      MIN (d->d_namlen + 1, buflen));
+	cp[0] = '\0';
+
+	if (stat (buf, &st) == 0 && st.st_dev == mydev)
+	  {
+	    (void) closedir (dirstream);
+	    errno = save;
+	    return 0;
+	  }
+      }
+
+  (void) closedir (dirstream);
+  errno = save;
+  return -1;
+}