my @files = <*.txt>;

##</code><code>##

{
    local @ARGV = <*.txt>;
    while( <> ) {
        // $_ contains the lines of the files one at a time; for each file in turn
    }
}

##</code><code>##

{ 
    local @ARGV = <*.txt>; 
    while( <> ) { 
        chomp; print $ARGV, '(', $., '):', $_; 
    } 
}