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-rw-r--r--lib/fopen-safer.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/lib/fopen-safer.c b/lib/fopen-safer.c
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+/* Invoke fopen, but avoid some glitches.
+
+ Copyright (C) 2001, 2004-2006, 2009-2013 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 Paul Eggert. */
+
+#include <config.h>
+
+#include "stdio-safer.h"
+
+#include <errno.h>
+#include <unistd.h>
+#include "unistd-safer.h"
+
+/* Like fopen, but do not return stdin, stdout, or stderr. */
+
+FILE *
+fopen_safer (char const *file, char const *mode)
+{
+ FILE *fp = fopen (file, mode);
+
+ if (fp)
+ {
+ int fd = fileno (fp);
+
+ if (0 <= fd && fd <= STDERR_FILENO)
+ {
+ int f = dup_safer (fd);
+
+ if (f < 0)
+ {
+ int e = errno;
+ fclose (fp);
+ errno = e;
+ return NULL;
+ }
+
+ if (fclose (fp) != 0
+ || ! (fp = fdopen (f, mode)))
+ {
+ int e = errno;
+ close (f);
+ errno = e;
+ return NULL;
+ }
+ }
+ }
+
+ return fp;
+}