Sed & Awk

  man bash  
  man awk  
  man sed  
  man grep

You can also do most of this stuff with Perl one liners if that suits your fancy.

sed + awk - https://www.amazon.com/sed-awk-Dale-Dougherty/dp/1565922255

awk - https://ia802309.us.archive.org/25/items/pdfy-MgN0H1joIoDVoI...

general *nix text processing - https://www.tldp.org/LDP/abs/html/textproc.html

This debate did nothing to solve a question spawned from this thread: should I learn perl or awk to handle my basic cli text-processing needs? (I have the sed & awk book ([sed&awk](https://www.amazon.com/sed-awk-Dale-Dougherty/dp/1565922255)) from o'reilly but only read the sed chapters. I have never wanted to learn perl b/c of the issue debated here. But melpomene's answer made me think it would be easier than awk and sed combined. Can I just learn basic perl to handle sed/awk type tasks? Why can't Python handle the same things as easily as perl did in melpomene's example?)