1 /* Invoke fopen, but avoid some glitches. 2 3 Copyright (C) 2001, 2004-2006, 2009-2012 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18 /* Written by Paul Eggert. */ 19 20 #include <config.h> 21 22 #include "stdio-safer.h" 23 24 #include <errno.h> 25 #include <unistd.h> 26 #include "unistd-safer.h" 27 28 /* Like fopen, but do not return stdin, stdout, or stderr. */ 29 30 FILE * 31 fopen_safer (char const *file, char const *mode) 32 { 33 FILE *fp = fopen (file, mode); 34 35 if (fp) 36 { 37 int fd = fileno (fp); 38 39 if (0 <= fd && fd <= STDERR_FILENO) 40 { 41 int f = dup_safer (fd); 42 43 if (f < 0) 44 { 45 int e = errno; 46 fclose (fp); 47 errno = e; 48 return NULL; 49 } 50 51 if (fclose (fp) != 0 52 || ! (fp = fdopen (f, mode))) 53 { 54 int e = errno; 55 close (f); 56 errno = e; 57 return NULL; 58 } 59 } 60 } 61 62 return fp; 63 } 64
