The construct you are showing is not 'anchored'. The only anchor expressions are '^' (beginning of string) and '$' (end of string). If I am understanding correctly, all you really care about are partial matches at the end of the current available string. Partial matches in the middle are already discarded as non-matches.

Is there a reason that you cannot simply keep starting from the same location until you receive an end-of-string, or find a match? Can this be more data than you want to hold?

If you can't do this, I can think of one (very ugly) option. Something like this: 

sub
example {
  $foo = "[&#\$]";
  $regex = "a\\d+[ars]{2,4}(aa|ab|ac)";
  $string="wle;fnaekf;fla;lkcnovnifa  ";
  $min = $regex."\$"."foo";
  if ($min !~ /\$$/) {
    $min .= '$';
  }
  $match = 0;
  $tot = length($string);
  $index = $tot;
  print "index is $index\n";
  while (1) {
    print "min is $min\n";
    eval {
      if ($string =~ m/$min/g) {
        $index = pos $string;
        $match = 1;
      }
    };
#   print "err is $@\n";
    last if $match;
    $min =~ s/..$//;
    last if $min eq "";
    if ($min !~ /\$$/) {
      $min .= '$';
    }
  }
  return $index;
}

$ind = example();

[download]
You will also have to special-case lines terminated with '\'.

In reply to Re^3: Did regex match fail because of "end of string"? by Illuminatus
in thread Did regex match fail because of "end of string"? by moritz

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