[qadmin@concon qw]$ perl -e '
$gamedir = "fortress";
$HOME    = $ENV{'HOME'};
$mapname = "2fort5";
if ( -f "$HOME/$gamedir/maps/$mapname.bsp" ) { print "It exists!\n" } else { print "$!\n" };
'
It exists!
[qadmin@concon qw]$ perl -e '
$gamedir = "fortress";
$HOME    = $ENV{'HOME'};
$mapname = "2fort5qra";
if ( -f "$HOME/$gamedir/maps/$mapname.bsp" ) { print "It exists!\n" } else { print "$!\n" };
'
No such file or directory
[qadmin@concon qw]$