(PHP 4, PHP 5, PHP 7) Return the effective user ID of the current process

(PECL sync >= 1.0.0) Decreases the count of the semaphore or waits

(PECL ev >= 0.2.0) Make a single, non-blocking sweep over the embedded loop.

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Retrieve the system error message associated with the given errno

(PECL ev >= 0.2.0) Establishes the current time by querying the kernel, updating the time returned by Ev::now

(PHP 5 >= 5.2.0, PHP 7) Calculate the group access list

(PHP 4, PHP 5, PHP 7) Execute an external program and display the output

(PHP 4 >= 4.3.0, PHP 5, PHP 7) Set an alarm clock for delivery of a signal

(PECL ev >= 0.2.0) Configures the watcher

(PECL eio >= 0.0.1dev) Change file permissions.