#! perl -w

use strict;
package MyModule;

sub isFile {
    my $file = shift; 	# a file in local directory expected	
    my $verbose = shift; 	# optional	
    if (! -f $file) {
        print STDERR "*** no such file $file in current directory\n";
        return 0;
    }
    else {
        print STDERR "... isFile $file\n" if $verbose;
        return 1;
    }
}

# more subs ...

1;