diff options
Diffstat (limited to 'REORG.TODO/sysdeps/posix/flock.c')
-rw-r--r-- | REORG.TODO/sysdeps/posix/flock.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/posix/flock.c b/REORG.TODO/sysdeps/posix/flock.c new file mode 100644 index 0000000000..5aeba7d1b8 --- /dev/null +++ b/REORG.TODO/sysdeps/posix/flock.c @@ -0,0 +1,56 @@ +/* Copyright (C) 1992-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C 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. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* This file implements the `flock' function in terms of the POSIX.1 `fcntl' + locking mechanism. In 4BSD, these are two incompatible locking mechanisms, + perhaps with different semantics? */ + +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/file.h> + +/* Apply or remove an advisory lock, according to OPERATION, + on the file FD refers to. */ +int +__flock (int fd, int operation) +{ + struct flock lbuf; + + switch (operation & ~LOCK_NB) + { + case LOCK_SH: + lbuf.l_type = F_RDLCK; + break; + case LOCK_EX: + lbuf.l_type = F_WRLCK; + break; + case LOCK_UN: + lbuf.l_type = F_UNLCK; + break; + default: + __set_errno (EINVAL); + return -1; + } + + lbuf.l_whence = SEEK_SET; + lbuf.l_start = lbuf.l_len = 0L; /* Lock the whole file. */ + + return __fcntl (fd, (operation & LOCK_NB) ? F_SETLK : F_SETLKW, &lbuf); +} + +weak_alias (__flock, flock) |