Recursive grepping

Sometimes you just need to grep recursively in a directory. If you’re using find $somedir -type f -exec grep $somestring {} \;, don’t:

Use xargs to avoid creating a bazillion grep processes:
find $somedir -type f -print | xargs grep $somestring

But spaces in the output of find (i.e., spaces in filenames) will confuse xargs, so use -print0 and xargs -0 instead:
find $somedir -type f -print0 | xargs -0 grep $somestring

Except that you can achieve the same effect with find, with \+:
find $somedir -type f -exec grep $somestring {} \+

Or you can just use recursive grep:
grep -r $somestring $somedir
except that find allows you to filter by file type, name, age, etc.