Regular Expressions and OpenOffice
Linux is extraordinary powerful with its processing commands like grep. However, OpenOffice Search and Replace has some of that power, one that few people are aware of.
A few examples with using OpenOffice to process data:
Find line containing string
Replace by placing find result on a new line
Find several characters within a range of allowed character values
Find an e-mail address
[A-Za-z0-9.-]+@[A-Za-z0-9.-]+ (note -- I do not claim this to be the perfect filter for finding emails)
Sort list of lines
That option is now available in Writer, but I used to have to use Calc (spreadsheet) for that.
Remove duplicates from list of lines
I usually do something like this by copy-pasting into Calc (the spreadsheet Open Office equivalent), highlighting that whole column, going Data>Filter>Standard filter. Under "Value" choose -not empty-. Click "More Options". Select "No Duplicates", then click OK. Paste the resulting list back into the Writer file.