A good series of piped commands with tools available basically everywhere can solve problems you had no idea could be so simple to solve.
man bash
man awk
man sed
man grep
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
awk: - GNU Awk User Guide - https://www.gnu.org/software/gawk/manual/gawk.html#Getting-S...
- Grymoire guide - http://www.grymoire.com/Unix/Awk.html
sed: - Grymoire guide - https://www.grymoire.com/Unix/Sed.html - Official docs - http://sed.sourceforge.net/#docs
https://www.ibm.com/developerworks/library/l-sed1/index.html https://developer.ibm.com/tutorials/l-awk1/
awk is pure magic.