Here are some quick links on bash regular expressions, pretty good links to bookmark, if you use, regular expressions in bash regularly. I especially like the tldp link at number 3.
- Renaming a whole bunch of files at once, in bash (ask.metafilter.com)
- bash math (amit-agarwal.co.in)
- Efficiency of regular expressions (johndcook.com)
- Autogenerate Regular Expressions with txt2re (readwriteweb.com)