while (<>) {
    chomp;
    print collect( $_ );
}

sub collect {
    local @ARGV = @_;
    join '', <>;
}

##</code><code>##

ls | perl ../perlmonks.pl

##</code><code>##

file2
line1file1
line2file1

##</code><code>##

print collect( 'file1' );
print collect( 'file2' );

##</code><code>##

line1file1
line2file1
line1file2
line2file2