proc_close is similar to pclose except that it only works on processes opened by proc_open. proc_close waits for the process to terminate, and returns its exit code. Open pipes to that process are closed when this function is called, in order to avoid a deadlock - the child process may not be able to exit while the pipes are open.
The proc_open resource that will be closed.
Returns the termination status of the process that was run. In case of an error then -1 is returned.
If PHP has been compiled with --enable-sigchild, the return value of this function is undefined.