table of contents
other versions
- stretch 0.8.3-1
FLOPEN(3) | Library Functions Manual | FLOPEN(3) |
NAME¶
flopen
—
reliably open and lock a file
LIBRARY¶
library “libbsd”SYNOPSIS¶
#include <sys/fcntl.h>
#include <bsd/libutil.h>
int
flopen
(const
char *path, int
flags);
int
flopen
(const
char *path, int
flags, mode_t
mode);
DESCRIPTION¶
Theflopen
() function opens or creates a file and
acquires an exclusive lock on it. It is essentially equivalent with calling
open
() with the same parameters followed by
flock
() with an operation
argument of LOCK_EX
, except that
flopen
() will attempt to detect and handle races that
may occur between opening / creating the file and locking it. Thus, it is well
suited for opening lock files, PID files, spool files, mailboxes and other
kinds of files which are used for synchronization between processes.
If flags includes
O_NONBLOCK
and the file is already locked,
flopen
() will fail and set
errno to EWOULDBLOCK
.
As with open
(), the additional
mode argument is required if
flags includes O_CREAT
.
RETURN VALUES¶
If successful,flopen
() returns a valid file descriptor.
Otherwise, it returns -1, and sets errno as described in
flock(2) and open(2).
SEE ALSO¶
errno(2), flock(2), open(2)AUTHORS¶
Theflopen
function and this manual page were written by
Dag-Erling Smørgrav
⟨des@FreeBSD.org⟩.
June 6, 2009 | Linux 4.9.0-9-amd64 |