As an alternative to iterating over @ARGV and opening each file yourself, you could use a combination of <> and $ARGV: 

my %total;
my %by_file;
while (<>) {
  chomp;
  $total{$_}++;
  $by_file{$ARGV}{$_}++;
}

[download]

A simple output routine: 

my @strings = sort keys %total;
for my $string ( @strings ) {
   print( "\t$string" );
}
print( "\n" );

for my $file ( keys %counts ) {
   print( $file );
   for my $string ( @strings ) {
      print( "\t$by_file{$file}{$string}" );
   }
   print( "\n" );
}

[download]

The file names are passed to the script in same fashion as in my first post.

In reply to Re: Piping many individual files into a single perl script by ikegami
in thread Piping many individual files into a single perl script by kelder

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.