use warnings; use strict; my $s;
$s = system q(cat),  qw(nosuchfile);       printf q(ret=0x%04x, err=>>%s<<%s), $s, $!, $/; $!=0;
$s = system q(xcat), qw(nosuchfile);       printf q(ret=0x%04x, err=>>%s<<%s), $s, $!, $/; $!=0;
$s = system q(perl), q(-le), q(exit 0x13); printf q(ret=0x%04x, err=>>%s<<%s), $s, $!, $/; $!=0;
$s = system q(perl), q(-le), q(exit 0xFF); printf q(ret=0x%04x, err=>>%s<<%s), $s, $!, $/; $!=0;

##</code><code>##

cat: nosuchfile: No such file or directory
ret=0x0100, err=>><<
Can't exec "xcat": No such file or directory at - line 3.
ret=0xffffffff, err=>>No such file or directory<<
ret=0x1300, err=>><<
ret=0xff00, err=>><<