Hi all,
I remember reading (probably in the Camel book) that
the more $1, $2 and so on you have in a regex the
slower the regex will be executed. It seems any
backreference is taxing performance considerably.
Is there an alternative? What I am trying to do is
isolate some patterns with each line of a text file
and then make small changes to those pieces and/or
switching the position of some of those pieces. Is it
possible to do that without back referencing?
For instance I start with:
ABc Sun May 20 19:45:30, 2001 XYZ
(tabs between the date and both fields to the right
and left, all other spaces are spaces) and I need to
get something like:
ABcD Sun May 20 19:45:30 XY Z
(tab between XY and Z, a new field).
The way I do it now is:
$row=~s/^([A-Z][A-Z][a-z])\t([A-Z][a-z][a-z]\s[A-Z][a-z][a-z]\s{1,2}\d{1,2}\s\d{2}:\d{2}:\d{2}).*?\t([A-Z])([A-Z])([A-Z]).*?/$1D\t$2\t$3$4\$5/
Ok, I could have get XY in $4 and reduce the back
references by one. Any other way to do it?
Thanks,
Dan
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