perlman root This section is surprisingly small because the rest of the FAQ is littered with answers involving regular expressions. For example, decoding a URL and checking whether something is a number are handled with regular expressions, but those answers are found elsewhere in this document (in the section on Data and the Networking one on networking, to be precise). [How can I hope to use regular expressions without creating illegible and unmaintainable code?] [I'm having trouble matching over more than one line. What's wrong?] [How can I pull out lines between two patterns that are themselves on different lines?] [I put a regular expression into $/ but it didn't work. What's wrong?] [How do I substitute case insensitively on the LHS, but preserving case on the RHS?] [How can I make <CODE>\w</CODE> match national character sets?] [How can I match a locale-smart version of <CODE>/[a-zA-Z]/</CODE>?] [How can I quote a variable to use in a regexp?] [What is <CODE>/o</CODE> really for?] [How do I use a regular expression to strip C style comments from a file?] [Can I use Perl regular expressions to match balanced text?] [What does it mean that regexps are greedy? How can I get around it?] [How do I process each word on each line?] [How can I print out a word-frequency or line-frequency summary?] [How can I do approximate matching?] [How do I efficiently match many regular expressions at once?] [Why don't word-boundary searches with <CODE>\b</CODE> work for me?] [Why does using $&, $`, or $' slow my program down?] [What good is <CODE>\G</CODE> in a regular expression?] [Are Perl regexps DFAs or NFAs? Are they POSIX compliant?] [What's wrong with using grep or map in a void context?] [How can I match strings with multibyte characters?]