From 5262a872f308b3b584c97d621992fb3877e392b8 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 05:10:08 +0200 Subject: Adding upstream version 5.6.1+really5.4.5. Signed-off-by: Daniel Baumann --- src/common/tuklib_open_stdxxx.c | 57 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 src/common/tuklib_open_stdxxx.c (limited to 'src/common/tuklib_open_stdxxx.c') diff --git a/src/common/tuklib_open_stdxxx.c b/src/common/tuklib_open_stdxxx.c new file mode 100644 index 0000000..26702a6 --- /dev/null +++ b/src/common/tuklib_open_stdxxx.c @@ -0,0 +1,57 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file tuklib_open_stdxxx.c +/// \brief Make sure that file descriptors 0, 1, and 2 are open +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "tuklib_open_stdxxx.h" + +#ifndef TUKLIB_DOSLIKE +# include +# include +# include +# include +#endif + + +extern void +tuklib_open_stdxxx(int err_status) +{ +#ifdef TUKLIB_DOSLIKE + // Do nothing, just silence warnings. + (void)err_status; + +#else + 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); + + // 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); + } + } + } +#endif + + return; +} -- cgit v1.2.3