Hi all.
There is a simple task: parse a long string to readable format.
only two main rules:
1. string must be less than 15 chracters before \n
2. put \n after comma if it is possible

it can be done using cicle of course: 
my $data = "0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,".('c'x50).",16,17,1
+8,19,20,21,22,23,24,25,26,27";

while ($data =~/[^\n]{16}/)
{
 $data =~s/([^\n]{16})/ch($1)/e;
}
print $data;
  
sub ch
{
 my $s = shift;
 my $p = rindex($s, ',', 14)+1;
 $p=15 unless($p);
 return substr($s, 0, $p)."\n".substr($s, $p)
};

[download]
or with help of recursion function, but i want try to do it using executable regexp with g option (instead of while). 
$data =~s/([^\n]{16})/ch($1)/ge;

[download]
but in with case result is wrong, because tail of previous result concatinates with head of new. To escape with situation we must to change current search position in regexp to earlier value (even if we set 0 it's ok). Pos() function allow to change search position in regexp, but it seems it can't be use inside of regexp itself.
With variant is nothing changes 
$data =~s/([^\n]{16})/pos($data)=0;ch($1)/ge;

[download]
So my question is: Is it possible change search position from regexp itself?

In reply to Using pos() inside regexp by braveghost

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