|Perl: the Markov chain saw|
Re: can understand one line of codeby roboticus (Chancellor)
|on Dec 19, 2012 at 15:39 UTC||Need Help??|
The s#xxx#yyy# is just an alternate form of s/xxx/yyyx. With the s and </c>m</c> operators, you can specify an alternate set of delimiters for your regex. It's often used to make an expression easier to read--for example, if you're altering strings with slashes in them (think directory paths), then you'd need to prefix each '/' with a '\' inside your regular expression if you used the typical '/' delimiter. If you choose a different delimiter, though, it can be easier to read. Note: You can also used curly braces, too. These three expressions are identical:
So since the grep statement gets a list of aliases, the statement is first altering the value, then checking whether it should be included in the output list. A trivial example:
Just my $0.02.
Update: Jiminy, I'm slow. Three answers before I replied, and they show that I goofed. I also obviously got it a bit wrong. (That's what I get for not testing.) I was expecting a variable expansion in the match portion of the regex. (I don't know *why* I expected it, as '$' is the 'end of line' match character. Perhaps I was thrown off by the use of something that looked like a variable name on the right side.) So anyway, I've stricken the bit that's patently incorrect, and underlined a bit of text I inserted to partially correct it.
When your only tool is a hammer, all problems look like your thumb.