A good series of piped commands with tools available basically everywhere can solve problems you had no idea could be so simple to solve.
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
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 is pure magic.
https://www.ibm.com/developerworks/library/l-sed1/index.html https://developer.ibm.com/tutorials/l-awk1/