(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)
shmop_read — Read data from shared memory block
shmop_read() will read a string from shared memory block.
shmop
The shared memory block identifier created by shmop_open()
offset
Offset from which to start reading; must be greater than or equal to zero and less than or equal to the actual size of the shared memory segment.
size
The number of bytes to read; must be greater than or equal to zero, and the sum of offset
and size
must be less than or equal to the actual size of the shared memory segment. 0
reads shmop_size($shmid) - $start
bytes.
Returns the data 或者在失败时返回 false
.
If offset
or size
are out of range, a ValueError is thrown.
版本 | 说明 |
---|---|
8.0.0 | shmop expects a Shmop instance now; previously, a resource was expected. |
8.0.0 | If offset or size are out of range, a ValueError is thrown; previously E_WARNING was emitted, and false was returned, |
示例 #1 Reading shared memory block
<?php
$shm_data = shmop_read($shm_id, 0, 50);
?>
This example will read 50 bytes from shared memory block and place the data inside $shm_data
.