The version above uses the three-element form of open() (available in perl 5.6.0 and later), which is a bit safer than the two-element form. open(FH, '<', $filename) is the same as open(FH, "<$filename"). The problem is that $filename could have a '<' at the beginning, thus changing the meaning of the open(). The three-element form avoids this problem.

And yes, $c and $b need to have special regex characters escaped. (As broquaint said, variables like $c and $b have special meanings and should be avoided, but let's ignore that for the moment). If '/' is your only problem character, you can use the 'choose your own quotes' feature of Perl's regexen, such as s!$c!$b!g. In this case, the regex substitution will use '!' as a delimiter instead of '/'.

----
I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated

In reply to Re: Re: Re: question on sed by hardburn
in thread question on sed by Anonymous Monk

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