int shmop_write (int shmid, string data, int offset)
shmop_write() will write a string into shared memory block.
shmop_write() takes 3 parameters: shmid, which is the shared memory block identifier created by shmop_open(), data, a string that you want to write into shared memory block and offset, which specifies where to start writing data inside the shared memory segment.
Example 1. Writing to shared memory block
<?php $shm_bytes_written = shmop_write($shm_id, $my_string, 0); ?>
This example will write data inside $my_string into shared memory block, $shm_bytes_written will contain the number of bytes written.