pcntl_wait — Waits on or returns the status of a forked child
int pcntl_wait ( int &$status [, int $options = 0 ] )
This function is equivalent to calling pcntl_waitpid() with a -1 pid and no options.
pcntl_wait() will store status information in the status parameter which can be evaluated using the following functions: pcntl_wifexited(), pcntl_wifstopped(), pcntl_wifsignaled(), pcntl_wexitstatus(), pcntl_wtermsig() and pcntl_wstopsig().
If wait3 is available on your system (mostly BSD-style systems), you can provide the optional options parameter. If this parameter is not provided, wait will be used for the system call. If wait3 is not available, providing a value for options will have no effect. The value of options is the value of zero or more of the following two constants OR'ed together:
Possible values for options
|WNOHANG || Return immediately if no child has exited. |
|WUNTRACED || Return for children which are stopped, and whose status has not been reported. |
pcntl_wait() returns the process ID of the child which exited, -1 on error or zero if WNOHANG was provided as an option (on wait3-available systems) and no child was available.