pipe

pipe readhandle, writehandle

Opens a pair of connected pipes. This call is almost always used right before a fork, after which the pipes reader should close writehandle, and the writer should close readhandle. (Otherwise the pipe won't indicate EOF to the reader when the writer closes it.) Note that if you set up a loop of piped processes, deadlock can occur unless you are very careful. In addition, note that Perl's pipes use standard I/O buffering, so you may need to set $| on your writehandle to flush after each output command, depending on the application - see select filehandle.