From e1908ae95dd4c9d19ee4dfabfc8bf8a7f85943fe Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 18:58:41 +0200 Subject: Adding upstream version 9.4. Signed-off-by: Daniel Baumann --- lib/fd-reopen.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 lib/fd-reopen.c (limited to 'lib/fd-reopen.c') diff --git a/lib/fd-reopen.c b/lib/fd-reopen.c new file mode 100644 index 0000000..f515077 --- /dev/null +++ b/lib/fd-reopen.c @@ -0,0 +1,46 @@ +/* Invoke open, but return either a desired file descriptor or -1. + + Copyright (C) 2005-2023 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program 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. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +/* Written by Paul Eggert. */ + +#include + +#include "fd-reopen.h" + +#include +#include +#include + +/* Open a file to a particular file descriptor. This is like standard + 'open', except it always returns DESIRED_FD if successful. */ + +int +fd_reopen (int desired_fd, char const *file, int flags, mode_t mode) +{ + int fd = open (file, flags, mode); + + if (fd == desired_fd || fd < 0) + return fd; + else + { + int fd2 = dup2 (fd, desired_fd); + int saved_errno = errno; + close (fd); + errno = saved_errno; + return fd2; + } +} -- cgit v1.2.3