2 files changed, 18 insertions, 1 deletions
diff --git a/libgfortran/io/io.h b/libgfortran/io/io.h
index e910fa58780..6774866745f 100644
--- a/libgfortran/io/io.h
+++ b/libgfortran/io/io.h
@@ -465,6 +465,8 @@ void empty_internal_buffer(stream *);
 #define flush prefix(flush)
 try flush (stream *);
 
+#define unit_to_fd prefix(unit_to_fd)
+int unit_to_fd (int);
 
 /* unit.c */
 
diff --git a/libgfortran/io/unix.c b/libgfortran/io/unix.c
index 2e9d9a4ba8c..5be631a9aab 100644
--- a/libgfortran/io/unix.c
+++ b/libgfortran/io/unix.c
@@ -286,7 +286,6 @@ sys_exit (int code)
 }
 
 
-
 /*********************************************************************
     File descriptor stream functions
 *********************************************************************/
@@ -918,6 +917,22 @@ fd_to_stream (int fd, int prot)
 }
 
 
+/* Given the Fortran unit number, convert it to a C file descriptor.  */
+
+int
+unit_to_fd(int unit)
+{
+
+  gfc_unit *us;
+
+  us = find_unit(unit);
+  if (us == NULL)
+    return -1;
+
+  return ((unix_stream *) us->s)->fd;
+}
+
+
 /* unpack_filename()-- Given a fortran string and a pointer to a
  * buffer that is PATH_MAX characters, convert the fortran string to a
  * C string in the buffer.  Returns nonzero if this is not possible.  */