xz/src/common/tuklib_open_stdxxx.c

58 lines
1.4 KiB
C
Raw Normal View History

2007-12-08 22:42:33 +00:00
///////////////////////////////////////////////////////////////////////////////
//
/// \file tuklib_open_stdxxx.c
2007-12-08 22:42:33 +00:00
/// \brief Make sure that file descriptors 0, 1, and 2 are open
//
// Author: Lasse Collin
2007-12-08 22:42:33 +00:00
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
2007-12-08 22:42:33 +00:00
//
///////////////////////////////////////////////////////////////////////////////
#include "tuklib_open_stdxxx.h"
2007-12-08 22:42:33 +00:00
#ifndef TUKLIB_DOSLIKE
# include <stdlib.h>
# include <errno.h>
# include <fcntl.h>
# include <unistd.h>
#endif
2007-12-08 22:42:33 +00:00
extern void
tuklib_open_stdxxx(int err_status)
2007-12-08 22:42:33 +00:00
{
#ifdef TUKLIB_DOSLIKE
// Do nothing, just silence warnings.
(void)err_status;
#else
2007-12-08 22:42:33 +00:00
for (int i = 0; i <= 2; ++i) {
// We use fcntl() to check if the file descriptor is open.
if (fcntl(i, F_GETFD) == -1 && errno == EBADF) {
// With stdin, we could use /dev/full so that
// writing to stdin would fail. However, /dev/full
// is Linux specific, and if the program tries to
// write to stdin, there's already a problem anyway.
const int fd = open("/dev/null", O_NOCTTY
| (i == 0 ? O_WRONLY : O_RDONLY));
if (fd != i) {
if (fd != -1)
(void)close(fd);
2007-12-08 22:42:33 +00:00
// Something went wrong. Exit with the
// exit status we were given. Don't try
// to print an error message, since stderr
// may very well be non-existent. This
// error should be extremely rare.
exit(err_status);
2007-12-08 22:42:33 +00:00
}
}
}
#endif
2007-12-08 22:42:33 +00:00
return;
}