[Chapter 7] 7.2.40 IPC::Open3 - Open a Process for Reading, Writing, and Error Handling

7.2.40 IPC::Open3 - Open a Process for Reading, Writing, and Error Handling

use IPC::Open3;

$pid = open3($WTR, $RDR, $ERR, $cmd_with_args);
$pid = open3($WTR, $RDR, $ERR, $cmd, "arg1", "arg2", ...);

IPC::Open3 works like IPC::Open2, with the following differences:

• The first two arguments ($WTR and $RDR) are given in reverse order compared to IPC::Open2.

• A third filehandle can be given, for standard error. If this argument is given as "", then STDERR and STDOUT for $cmd will be on the same filehandle.

• If $WTR begins with <&, then the leading <& is stripped from the name and the remainder is assumed to be a regular filehandle for an open file, rather than a reference to a typeglob. open3() opens this file as STDIN for $cmd and closes it in the parent. Likewise, if $RDR or $ERR begins with >&, then $cmd directs STDOUT or STDERR directly to that file rather than to the parent.

Warnings given for IPC::Open2 regarding possible program hangs apply to IPC::Open3 as well.