bandie91 / php5-pipe2

wrapper functions for pipe(2) and dup2(2) syscalls

pipe(2) binding for PHP

It is a PHP extension provides functions for low-level file descriptor operations:

• posix_pipe() binds to pipe() syscall
• posix_dup2() binds to dup2() syscall
• posix_close() binds to close() syscall

Have you ever wondered how to do cheap forking and running subprocesses?

PHP already provides exec(), system() and proc_open() to run a child process, but with not as little overhead as possible. exec(), system() and proc_open() spawns shell first.

You can use pcntl family to build a low cost exec function. However pcntl is not available in all SAPI. You will need pcntl_fork() and pcntl_exec() then pcntl_waitpid() to implement a subprocess executing function. In this case you lose the child process' output, stderr and the ability to pipe data into its stdin, which is built in proc_open() by default and partially in exec() (only stdout is captured).

A possible low-level solution is to request pipes from the OS and redirecting them in the child process before exec'ing. This module provides bindings to POSIX API functions suitable for this job.

Usage

array posix_pipe() Returns an array holding stream resources for the new pipe's reader and writer end, and their file descriptors.

[0] => stream reader,
[1] => stream writer,
[2] => int reader_fd,
[3] => int writer_fd,

bool posix_dup2(mixed oldfd, mixed newfd) oldfd and newfd can be stream type resources or int. Returns TRUE if success, FALSE otherwise. bool posix_close(int fd) Returns TRUE if success, FALSE otherwise.

Example

see example.php

issues

Please submit issues via PR to some file <TITLE>.txt or <TITLE>.md on issues branch.