in reply to Shift regex search back 4 characters...

In the spirit of TIMTOWTDI, here is one way to actually move the search point back. 

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1183627

use strict;
use warnings;

$_ = '222,345,222,678,222,222,543,111';

while( /222,(\d\d\d)/g )
  {
  print "AFTER 222-$1\n";
  pos($_) -= 4; # actually move back 4 characters
  }

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Re^2: Shift regex search back 4 characters...
by AnomalousMonk (Archbishop) on Mar 13, 2017 at 05:47 UTC

    A variation that doesn't require foreknowledge of the backward step length: 

    c:\@Work\Perl\monks>perl -wMstrict -le
"$_ = '222,345,222,678,222,223,224,543,111,222';
 ;;
 while ( /22[2345],(\d\d\d)/g ) {
   print qq{after 22n: '$1'};
   pos = $-[1];
   }
"
after 22n: '345'
after 22n: '678'
after 22n: '223'
after 22n: '224'
after 22n: '543'

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    Give a man a fish:  <%-{-{-{-<

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