Comment by tomhrr

The 'sh' command that it corresponds to is above it:

  find . -iname '*test*' -print0 | xargs -0 grep data

but possibly a bad assumption on my part that the mapping was clear. In any event, 'm' is for regex string matching, and 'f<' is for reading a file into a generator (basically an iterator over the lines in the file). It's a good point that more, simpler examples would help.