I was attempting to come up with a new function for my HTML-shortcuts system today.

I wrote a subroutine that calls on Image::Magick to get the height and width of an image.

This means all I have to do is put i myimage.gif (i for image) into the form box, and use a regex to process that line like this:

$body =~ s/\ni ([^\n]*?)\n/makeImageTag(\1)/eg;

and have the sub make the image tag for me, with the height and width inserted automatically. This is a Good Thing.

But the damn thing didn't work! So I thought "what would a true monk do?" and turned on warnings.

Cue angelic choir -- warnings tell me that I shouldn't use \1, I should use $1.

So I'm not here to ask the monks that dumb question, but can someone explain what the difference is between \1 and $1? Obviously I can't use the former when there's an expression to be evaluated...
-- 

($_='jjjuuusssttt annootthhrer
     pppeeerrrlll haaaccckkeer')=~y/a-z//s;print;

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In reply to Warnings Are Good! Plus A Question about $1 by Cody Pendant

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