Compzone.Org :: Podręcznik PHP :: dio_fcntl

Podręcznik PHP
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dio_fcntl

(PHP 4 >= 4.2.0, PHP 5 <= 5.0.4)

dio_fcntl -- Performs a c library fcntl on fd

Opis

mixed dio_fcntl ( resource fd, int cmd [, mixed args] )

The dio_fcntl() function performs the operation specified by cmd on the file descriptor fd. Some commands require additional arguments args to be supplied.

Notatka: Ta funkcja nie jest dostępna na platformie Windows.

Parametry

fd

The file descriptor returned by dio_open().

cmd

Can be one of the following operations:

F_SETLK - Lock is set or cleared. If the lock is held by someone else dio_fcntl() returns -1.
F_SETLKW - like F_SETLK, but in case the lock is held by someone else, dio_fcntl() waits until the lock is released.
F_GETLK - dio_fcntl() returns an associative array (as described above) if someone else prevents lock. If there is no obstruction key "type" will set to F_UNLCK.
F_DUPFD - finds the lowest numbered available file descriptor greater than or equal to args and returns them.
F_SETFL - Sets the file descriptors flags to the value specified by args, which can be O_APPEND, O_NONBLOCK or O_ASYNC. To use O_ASYNC you will need to use the PCNTL extension.

args

args is an associative array, when cmd is F_SETLK or F_SETLLW, with the following keys:

"start" - offset where lock begins
"length" - size of locked area. zero means to end of file
"wenth" - Where l_start is relative to: can be SEEK_SET, SEEK_END and SEEK_CUR
"type" - type of lock: can be F_RDLCK (read lock), F_WRLCK (write lock) or F_UNLCK (unlock)

Zwracane wartości

Returns the result of the C call.

Przykłady

Przykład 1. Setting and clearing a lock

<?php

                

                $fd = dio_open('/dev/ttyS0', O_RDWR);

                

                if (dio_fcntl($fd, F_SETLK, Array("type"=>F_WRLCK)) == -1) {

                   // the file descriptor appears locked


                   echo "The lock can not be cleared. It is held by someone else.";


                } else {

                   echo "Lock succesfully set/cleared";


                }

                
dio_close($fd);
?>

Poprzedni	Spis treści	Następny
dio_close	Początek rozdziału	dio_open