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-rw-r--r--stdio/fmemopen.c108
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;
+}