IPC::Open3

IPC::Open3 works like IPC::Open2.

use IPC::Open3; $pid = open3($wtr, $rdr, $err, $cmd_with_args); $pid = open3($wtr, $rdr, $err, $cmd, "arg1", "arg2", ...);

The following differences apply:

The first two arguments ($wtr and $rdr) are passed in the opposite order.
A third filehandle can be passed, for standard error. If this argument is given as "", then STDERR and STDOUT for $cmd are 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.