diff options
author | Jim Meyering <jim@meyering.net> | 2001-03-03 19:05:36 +0000 |
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committer | Jim Meyering <jim@meyering.net> | 2001-03-03 19:05:36 +0000 |
commit | 196a4d4693a1b50eb309df386dfb5a0f72169d88 (patch) | |
tree | dee1d3f28ef42ce0722d6b6b82b063a19e5a990b /lib/fopen-safer.c | |
parent | 5c3a739a8a803e3bc50dfd4caff751ce6843fc76 (diff) | |
download | gnulib-196a4d4693a1b50eb309df386dfb5a0f72169d88.tar.gz |
from Paul Eggert
Diffstat (limited to 'lib/fopen-safer.c')
-rw-r--r-- | lib/fopen-safer.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/lib/fopen-safer.c b/lib/fopen-safer.c new file mode 100644 index 0000000000..6825f9b9f2 --- /dev/null +++ b/lib/fopen-safer.c @@ -0,0 +1,76 @@ +/* Invoke fopen, but avoid some glitches. + Copyright (C) 2001 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 2, 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, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* Written by Paul Eggert. */ + +#if HAVE_CONFIG_H +# include <config.h> +#endif + +#if HAVE_UNISTD_H +# include <unistd.h> +#endif +#include <unistd-safer.h> + +#ifndef STDERR_FILENO +# define STDERR_FILENO 2 +#endif + +#include <errno.h> +#ifndef errno +extern int errno; +#endif + +#include <stdio.h> +#include <stdio-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; +} |