open (FILE, "file") || die "file could not be opened";

##</code><code>##

$file = "some_file.txt"; 
open(FILE,"$file") or &Error($!); 

##</code><code>##

sub Error {
        $error = shift or $error = "unknown";
        print "Sorry, but there was an error.  Could not open $file";
        print "Error:  $error";
        &End;
}

##</code><code>##

close FILE or die "Could not close $file";