The scripting languages like Perl and Ruby are very well-known for expressing the data crunching task into one-liner. With their command line flags like -p, -e and default variable $_ with regular expression. The job just gets easier. I believe functional languages are also good at one-liner, since lambda-like structure are good in data transformation. Here is a few I would do with Haskell.
number each line of files
ghc -e "print . (zip [1..]) . lines =<< getContents" ghc -e "print . (filter (/= '\n')) =<< getContents"
ghc -e "print . length . lines =<< getContents"
print specific line
ghc -e "print . (filter (\x -> (fst x) == 1)) . (zip [1..]) . lines =<< getContents"
Regular expression is relatively painful in Haskell. In order to use it you have to add the modules you would like to load in evaluation mode first.
Then hit with POSIX regular expression syntax.
ghc -e 'print . (map (\s -> subRegex (mkRegex "^[[:space:]]+") s "")) . lines =<< getContents'
I would add more if I can think of others.