to calling proc_close().
Implement proc_get_status(resource $process) which returns an array of
information about a process created with proc_open().
The information includes:
array(
"command" => string "name of the command",
"pid" => long process identifier,
"running" => bool true if the process is still running
"exitcode" => long exitcode if the process exited
"signaled" => bool true if the process was signaled
"termsig" => long signal number if signaled
"stopped" => bool true if the process is stopped
"stopsig" => long signal number if stopped
);