181ad8388SMartin Matuska ///////////////////////////////////////////////////////////////////////////////
281ad8388SMartin Matuska //
381ad8388SMartin Matuska /// \file tuklib_open_stdxxx.c
481ad8388SMartin Matuska /// \brief Make sure that file descriptors 0, 1, and 2 are open
581ad8388SMartin Matuska //
681ad8388SMartin Matuska // Author: Lasse Collin
781ad8388SMartin Matuska //
82f9cd13dSXin LI // This file has been put into the public domain.
92f9cd13dSXin LI // You can do whatever you want with this file.
102f9cd13dSXin LI //
1181ad8388SMartin Matuska ///////////////////////////////////////////////////////////////////////////////
1281ad8388SMartin Matuska
1381ad8388SMartin Matuska #include "tuklib_open_stdxxx.h"
1481ad8388SMartin Matuska
1581ad8388SMartin Matuska #ifndef TUKLIB_DOSLIKE
1681ad8388SMartin Matuska # include <stdlib.h>
1781ad8388SMartin Matuska # include <errno.h>
1881ad8388SMartin Matuska # include <fcntl.h>
1981ad8388SMartin Matuska # include <unistd.h>
2081ad8388SMartin Matuska #endif
2181ad8388SMartin Matuska
2281ad8388SMartin Matuska
2381ad8388SMartin Matuska extern void
tuklib_open_stdxxx(int err_status)2481ad8388SMartin Matuska tuklib_open_stdxxx(int err_status)
2581ad8388SMartin Matuska {
2681ad8388SMartin Matuska #ifdef TUKLIB_DOSLIKE
2781ad8388SMartin Matuska // Do nothing, just silence warnings.
2881ad8388SMartin Matuska (void)err_status;
2981ad8388SMartin Matuska
3081ad8388SMartin Matuska #else
3181ad8388SMartin Matuska for (int i = 0; i <= 2; ++i) {
3281ad8388SMartin Matuska // We use fcntl() to check if the file descriptor is open.
3381ad8388SMartin Matuska if (fcntl(i, F_GETFD) == -1 && errno == EBADF) {
3481ad8388SMartin Matuska // With stdin, we could use /dev/full so that
3581ad8388SMartin Matuska // writing to stdin would fail. However, /dev/full
3681ad8388SMartin Matuska // is Linux specific, and if the program tries to
3781ad8388SMartin Matuska // write to stdin, there's already a problem anyway.
3881ad8388SMartin Matuska const int fd = open("/dev/null", O_NOCTTY
3981ad8388SMartin Matuska | (i == 0 ? O_WRONLY : O_RDONLY));
4081ad8388SMartin Matuska
4181ad8388SMartin Matuska if (fd != i) {
42e24134bcSMartin Matuska if (fd != -1)
43e24134bcSMartin Matuska (void)close(fd);
44e24134bcSMartin Matuska
4581ad8388SMartin Matuska // Something went wrong. Exit with the
4681ad8388SMartin Matuska // exit status we were given. Don't try
4781ad8388SMartin Matuska // to print an error message, since stderr
4881ad8388SMartin Matuska // may very well be non-existent. This
4981ad8388SMartin Matuska // error should be extremely rare.
5081ad8388SMartin Matuska exit(err_status);
5181ad8388SMartin Matuska }
5281ad8388SMartin Matuska }
5381ad8388SMartin Matuska }
5481ad8388SMartin Matuska #endif
5581ad8388SMartin Matuska
5681ad8388SMartin Matuska return;
5781ad8388SMartin Matuska }
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