shmop_write(3) [php man page]

SHMOP_WRITE(3)								 1							    SHMOP_WRITE(3)

shmop_write - Write data into shared memory block

SYNOPSIS

       int shmop_write (int  $shmid, string  $data, int  $offset)

DESCRIPTION

       shmop_write(3) will write a string into shared memory block.

PARAMETERS

	      o $shmid
		- The shared memory block identifier created by shmop_open(3)

	      o $data
		- A string to write into shared memory block

	      o $offset
		- Specifies where to start writing data inside the shared memory segment.

RETURN VALUES

	The size of the written $data, or FALSE on failure.

EXAMPLES

       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.

SEE ALSO

       shmop_read(3).

PHP Documentation Group 													    SHMOP_WRITE(3)

shmop(2)							System Calls Manual							  shmop(2)

Name
       shmop, shmat, shmdt - shared memory operations

Syntax
       #include <sys/types.h>
       #include <sys/ipc.h>
       #include <sys/shm.h>

       char *shmat (shmid, shmaddr, shmflg)
       int shmid;
       char *shmaddr;
       int shmflg;

       int shmdt (shmaddr)
       char *shmaddr;

Description
       The  system  call attaches the shared memory segment associated with the shared memory identifier specified by shmid to the data segment of
       the calling process.  The segment is attached at the address specified by one of the following criteria:

       If shmaddr is equal to zero, the segment is attached at the first available address as selected by the system.

       If shmaddr is not equal to zero and (shmflg & SHM_RND ) is true, the segment is attached at the address given by (shmaddr- (shmaddr modulus
       SHMLBA )).

       If shmaddr is not equal to zero and (shmflg & SHM_RND ) is false, the segment is attached at the address given by shmaddr.

       The segment is attached for reading if (shmflg & SHM_RDONLY ) is true. Otherwise, it is attached for reading and writing.

       The system call detaches from the calling process's data segment the shared memory segment located at the address specified by shmaddr.

Return Values
       Upon successful completion, the return values are as follows:

       o   The system call returns the data segment start address of the attached shared memory segment.

       o   The system call returns a value of zero (0).

       Otherwise, a value of -1 is returned, and errno is set to indicate the error.

Diagnostics
       The system call fails and not attach the shared memory segment, if any of the following is true:

       [EINVAL]       The shmid is not a valid shared memory identifier.

       [EACCES]       Operation permission is denied to the calling process.  For further information, see

       [ENOMEM]       The available data space is not large enough to accommodate the shared memory segment.

       [EINVAL]       The shmaddr is not equal to zero, and the value of (shmaddr- (shmaddr modulus SHMLBA )) is an illegal address.

       [EINVAL]       The shmaddr is not equal to zero, (shmflg & SHM_RND ) is false, and the value of shmaddr is an illegal address.

       [EMFILE]       The number of shared memory segments attached to the calling process would exceed the system imposed limit.

       The fails and does not detach the shared memory segment if:

       [EINVAL]       The shmaddr is not the data segment start address of a shared memory segment.

See Also
       execve(2), exit(2), fork(2), shmctl(2), shmget(2)

																	  shmop(2)