1 files changed, 108 insertions, 0 deletions
diff --git a/stdio/fmemopen.c b/stdio/fmemopen.c
new file mode 100644
index 0000000000..42a137a2c8
--- /dev/null
+++ b/stdio/fmemopen.c
@@ -0,0 +1,108 @@
+/* Copyright (C) 1991, 1992, 1993 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 <ansidecl.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+/* Defined in fopen.c.  */
+extern int EXFUN(__getmode, (CONST char *mode, __io_mode *mptr));
+
+/* Open a new stream that will read and/or write from the buffer in
+   S, which is of LEN bytes.  If the mode indicates appending, the
+   buffer pointer is set to point to the first '\0' in the buffer.
+   If S is NULL, the buffer is allocated by malloc and will be freed
+   when the stream is closed.  The only purpose of this is to write
+   things and then read what's been written.  If LEN is zero, writes will
+   always return errors and reads will always return end-of-file.
+
+   The stream is set up such that seeks and tells will always fail and
+   once the buffer is full of written characters or empty of characters
+   to read, attempted writes always return an output error and attempted
+   reads always return end-of-file.  */
+FILE *
+DEFUN(fmemopen, (s, len, mode),
+      PTR s AND size_t len AND CONST char *mode)
+{
+  __io_mode m;
+  register FILE *stream;
+
+  if (!__getmode (mode, &m))
+    return NULL;
+
+  stream = __newstream ();
+  if (stream == NULL)
+    return NULL;
+
+  stream->__mode = m;
+
+  /* Input gets EOF.  */
+  stream->__room_funcs.__input = NULL;
+  /* Output gets error.  */
+  stream->__room_funcs.__output = NULL;
+
+  /* Do nothing for close.  */
+  stream->__io_funcs.__close = NULL;
+  /* Can't seek outside the buffer.  */
+  stream->__io_funcs.__seek = NULL;
+  /* There is no associated file descriptor to fetch.  */
+  stream->__io_funcs.__fileno = NULL;
+
+  stream->__seen = 1;
+
+  stream->__userbuf = s != NULL && len > 0;
+  if (s == NULL)
+    {
+      s = malloc (len);
+      if (s == NULL)
+	{
+	  int save = errno;
+	  (void) fclose (stream);
+	  errno = save;
+	  return NULL;
+	}
+    }
+
+  stream->__buffer = (char *) s;
+  stream->__bufsize = len;
+
+  stream->__bufp = stream->__buffer;
+  stream->__get_limit = (stream->__buffer +
+			 (stream->__mode.__read ? stream->__bufsize : 0));
+  stream->__put_limit = (stream->__buffer +
+			 (stream->__mode.__write ? stream->__bufsize : 0));
+  stream->__cookie = NULL;
+
+  if (stream->__mode.__append)
+    {
+      char *p = memchr (stream->__bufp, '\0',
+			stream->__get_limit - stream->__bufp);
+      if (p == NULL)
+	stream->__bufp = stream->__get_limit;
+      else
+	stream->__bufp = p;
+    }
+  else if (stream->__mode.__truncate)
+    memset ((PTR) stream->__buffer, 0, len);
+
+  return stream;
+}