$ cat ./746989.pl
my $filename = shift;

if ($line = /something/) {
}

foreach (@arr) {
   if (/abc/) {
      print;
   }
}

sub foo {
   my $x = shift;
}
$
$ perl -MO=Deparse ./746989.pl
my $filename = shift @ARGV;
if ($line = /something/) {
    ();
}
foreach $_ (@arr) {
    if (/abc/) {
        print $_;
    }
}
sub foo {
    my $x = shift @_;
}
./746989.pl syntax OK
$
$ perl -v

This is perl, v5.8.5 built for x86_64-linux-thread-multi