First of all, many thanks for your valuable input and kind assistance!

I have managed to generate a statistics for the XML entities in a file in two steps:

  1. generate a list of XML entities via entityList.pl
  2. generate a statistics which describes each entity and its frequency via entityStat.pl
Would it be possible to combine the functionality of the 2 perl scripts into one comprehensive script? If yes, how could I achieve this?

entityList.pl

#!/usr/bin/perl
use warnings;
use strict;

my $infile = $ARGV[0];

print "List of entities in ", $infile, "\n";

#define regexes as search target (in the array @regexes)
my $regex = qr/(&[^;]+;)/;

open my $in, '<', $infile or die "Cannot open $infile for reading: $!"
+;

#read input file in variable $xml
my $xml;
{
  local $/ = undef;
  $xml = <$in>;
}

#define output file
open my $out, '>', 'ent-list.txt' or die $!;

#output list of entities
print {$out} "$1\n" while $xml =~ /$regex/g;
 
close $in;
close $out;

[download]

entityStat.pl

#!/usr/bin/env perl
use strict;
use warnings;

my $infile = $ARGV[0];
my $outfile = $ARGV[1];   

open(IN, '<' . $infile) or die "Cannot open $infile for reading: $!";
open(OUT, '>' . $outfile) or die $!;
chomp(my @matches = <IN>);

my %freq;
$freq{$_}++ for @matches;

print OUT "Statistics of entities in '", $infile, "'\n================
+=================================\n";
for my $entity (sort keys %freq) {    
    printf OUT "%-20s %10s \n", $entity, $freq{$entity};
}

[download]

In reply to Re^2: Counting matches and removing duplicates by LexPl
in thread Counting matches and removing duplicates by LexPl

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.