On 5/11/07, Tom Phoenix <[EMAIL PROTECTED]> wrote:
On 5/11/07, Steve Finkelstein <[EMAIL PROTECTED]> wrote:> sflinux themes # echo 500 | perl -ple 's|(\d)|length(9 x $1)|eg;' > 500 > essentially, (\d) should match just the '5' in 500. that puts $1 == the > literal 5. so you take length(9 x 5) which is nine repeated 5 times, and > the length of that is 5. That replaces the 5 with a ... 5? > > Is my logic correct on this? I think you've got it, except it doesn't stop with the 5. Unless I'm missing something, that substitution means the same thing as this simpler one: s#(\d)#$1#g Unless the value of $1 is useful, it's hard to see what good this does. It replaces each digit with itself. As side effects it affects all the match variables, and it stringifies its target. Did you find that piece of code somewhere? Do you know what its author was trying to do? --Tom Phoenix Stonehenge Perl Training
Beyond obfuscation, I can only think of one reason to write something like that: un-tainting. But even then it is bad regex for that since it doesn't validate anything. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
