use strict;
use warnings;
sub fred {
    my $fname = 'f.tmp';
    open( my $fh, '<', $fname ) or die "error: open '$fname': $!";
    print "file '$fname' opened ok\n";
    # ... process file here
    die "oops";   # if something went wrong
    close($fh);
}
my $ok = eval { fred(); 1 };    # see [id://11130946]
if (!$ok) { print "died: $@\n" }
print "ok, \$fh is auto-closed when sub fred exits (normally or via die)\n";