The php Function Pcntl_Wexitstatus

PHP provides support for Unix signals as part of the POSIX standard. This allows the developer to manipulate the standard signal model and perform tasks such as waiting for child processes to quit or announcing a stop signal. In this article, we will look at the php function pcntl_wexitstatus and how it can be used to communicate with children processes after they terminate.

In a program, functions are reusable blocks of code that can be called multiple times to execute the same task. Functions are defined by a function name followed by open and closed parenthesis, and the function can accept any data type. Information is passed to the function through arguments, which are variables that start with a letter or an underscore. Arguments are separated by commas and can be added multiple times.

The pcntl_waitpid() function will wait for a child process to exit and stores the child’s status in a variable. The return value can be -1, a signal identifier or an exit code of the parent process. If the pcntl_waitpid() returns an exit code of -1 it means that the fork failed and no child process was created.

A pcntl_wexitstatus() function is an alternative way of getting the exit code for a child process after it terminates. This function requires the return value of a call to pcntl_fork(), the child process ID (PID) and a flag indicating whether or not to check the status for the exit code.