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- WareLogging, sort of. Regular expressions are wonderful (and wonderfully ugly) little creatures used to describe patterns in text. Useful in good TextEditors, or in a language like PerlLanguage. This page is a repository of useful regex stuff.
-
- = resources =
-
- * LinuxInANutshell, 2nd edition
- ** p. 69, grep
- ** p. 247, pattern matching
- ** p. 208, perl quickref regex section
-
- = WareLogging =
-
- * PerlCompatibleRegularExpressions
-
- = thoughts & recipes =
-
- An EvolvingRegularExpression
-
- Use egrep for complex expressions. Otherwise you will have to escape ?, +, {, |, (, and ) in order to get them to behave as special characters. If you're used to writing in Perl or similar, keep in mind that vi / VimEditor pattern matching will treat at least some of these characters as literals unless you escape them.
-
- (?<! ''regex'') ''other stuff''
- is a zero-width negative lookbehind assertion. Matches, in
- other words, if ''regex'' does *not* precede the ''other stuff''.
-
- egrep -ri "^[a-z., ]+$" ./*.dir
- Shows lines which are just alphanumeric plus period,
- comma, and space characters in all files with
- the extension .dir.
-
- tail -f /var/log/p1k3.access_log | egrep -vi "(googlebot|slurp)"
- following log file, wanted to avoid bot traffic noise
- may well eat CPU.
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