Top 5 Shell Commands for Working with Data Files

I also regularly use tee to take copies of data from the middle of a complex pipeline, and I regularly pipe results into a a file, background the task, and then monitor with tail or tail -f.

  # complex_command > output_file &
  # tail -f output_file

This allows me to leave the ask running while I do other things, then come back and check on it latter. It also lets me use ETA to estimate when tasks will finish.

Typos:

"Here's my top 5 ..." should be "Here are my top 5 ..."

"At it's simplest ..." should be "At its simplest ..."

"... a single file in to many." should be "... a single file into many." Same error occurs shortly after.

"...a work on Awk ..." should be "...a word on AWK ..."

I've posted this to HN for the discussion more than anything else.

What are your top shell commands for working with data files?