| flopen.3 (171705) | flopen.3 (171706) |
|---|---|
| 1.\"- 2.\" Copyright (c) 2007 Dag-Erling Co�dan Sm�rgrav 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 9 unchanged lines hidden (view full) --- 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" | 1.\"- 2.\" Copyright (c) 2007 Dag-Erling Co�dan Sm�rgrav 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright --- 9 unchanged lines hidden (view full) --- 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" |
| 26.\" $FreeBSD: head/lib/libutil/flopen.3 171705 2007-08-03 06:32:45Z des $ | 26.\" $FreeBSD: head/lib/libutil/flopen.3 171706 2007-08-03 09:20:28Z des $ |
| 27.\" | 27.\" |
| 28.Dd July 30, 2007 | 28.Dd May 10, 2007 |
| 29.Dt FLOPEN 3 30.Os 31.Sh NAME 32.Nm flopen 33.Nd "Reliably open and lock a file" 34.Sh LIBRARY 35.Lb libutil 36.Sh SYNOPSIS --- 4 unchanged lines hidden (view full) --- 41.Ft int 42.Fn flopen "const char *path" "int flags" "mode_t mode" 43.Sh DESCRIPTION 44The 45.Fn flopen 46function opens or creates a file and acquires an exclusive lock on it. 47It is essentially equivalent with calling 48.Fn open | 29.Dt FLOPEN 3 30.Os 31.Sh NAME 32.Nm flopen 33.Nd "Reliably open and lock a file" 34.Sh LIBRARY 35.Lb libutil 36.Sh SYNOPSIS --- 4 unchanged lines hidden (view full) --- 41.Ft int 42.Fn flopen "const char *path" "int flags" "mode_t mode" 43.Sh DESCRIPTION 44The 45.Fn flopen 46function opens or creates a file and acquires an exclusive lock on it. 47It is essentially equivalent with calling 48.Fn open |
| 49with the same parameters and then acquiring a lock on the entire file 50using 51.Fn fcntl "F_SETLK" , | 49with the same parameters followed by 50.Fn flock 51with an 52.Va operation 53argument of 54.Dv LOCK_EX , |
| 52except that 53.Fn flopen 54will attempt to detect and handle races that may occur between opening 55/ creating the file and locking it. 56Thus, it is well suited for opening lock files, PID files, spool 57files, mailboxes and other kinds of files which are used for 58synchronization between processes. 59.Pp --- 18 unchanged lines hidden (view full) --- 78.Dv O_CREAT . 79.Sh RETURN VALUES 80If successful, 81.Fn flopen 82returns a valid file descriptor. 83Otherwise, it returns -1, and sets 84.Va errno 85as described in | 55except that 56.Fn flopen 57will attempt to detect and handle races that may occur between opening 58/ creating the file and locking it. 59Thus, it is well suited for opening lock files, PID files, spool 60files, mailboxes and other kinds of files which are used for 61synchronization between processes. 62.Pp --- 18 unchanged lines hidden (view full) --- 81.Dv O_CREAT . 82.Sh RETURN VALUES 83If successful, 84.Fn flopen 85returns a valid file descriptor. 86Otherwise, it returns -1, and sets 87.Va errno 88as described in |
| 86.Xr fcntl 2 | 89.Xr flock 2 |
| 87and 88.Xr open 2 . 89.Sh SEE ALSO 90.Xr errno 2 , | 90and 91.Xr open 2 . 92.Sh SEE ALSO 93.Xr errno 2 , |
| 91.Xr fcntl 2 , | 94.Xr flock 2 , |
| 92.Xr open 2 93.Sh AUTHORS 94.An -nosplit 95The 96.Nm 97function and this manual page were written by 98.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org . | 95.Xr open 2 96.Sh AUTHORS 97.An -nosplit 98The 99.Nm 100function and this manual page were written by 101.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org . |