$ perl -MO=Deparse -e '<*>'
use File::Glob ();
glob('*');
-e syntax OK

##</code><code>##

    foreach $file (@files) {
        open FH, $file or
            die "Error opening $file: $!\n";

##</code><code>##

for my $file (@files) {
    open my $fh, '<', $file or
      die "Error opening `$file': $!\n";
    # do something with $fh
    # ...
    # no need for an explit close() 
}

##</code><code>##

$ cat foo.pl
#!/usr/bin/perl

use strict;
use warnings;

my $file=shift;
open my $fh, $file or die $!;

print "The contents of `$file' are:\n", <$fh>;

__END__

$ ./foo.pl aaa 
The contents of `aaa' are:
asdfdaf
sfdfdd
sffgsdd

$ ./foo.pl '|echo "Gotcha!">foo.pl'
The contents of `|echo "Gotcha!">foo.pl' are:

$ cat foo.pl
Gotcha!

##</code><code>##

      elsif ( data =~ /^\x89PNG\x0d\x0a\x1a\x0a/) {
         type = 'PNG';
      }