| /////////////////////////////////////////////////////////////////////////////// |
| // |
| /// \file open_stdxxx.h |
| /// \brief Make sure that file descriptors 0, 1, and 2 are open |
| // |
| // This code has been put into the public domain. |
| // |
| // This library 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. |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #ifndef OPEN_STDXXX_H |
| #define OPEN_STDXXX_H |
| |
| #include <stdlib.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| |
| |
| static void |
| open_stdxxx(int status) |
| { |
| 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) { |
| // 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. |
| (void)close(fd); |
| exit(status); |
| } |
| } |
| } |
| |
| return; |
| } |
| |
| #endif |