Old school programmer who likes to code, test and try.

My Favorites:

http://stackoverflow.com/questions/42239179/fastest-way-to-find-lines-of-a-text-file-from-another-larger-text-file-in-bash

Use and replace special non ascii double quotes like U+201c & U+201d
http://stackoverflow.com/questions/43458809/escaping-double-quotation-marks-in-sed/43461815#43461815

Converting CSV to TSV

http://stackoverflow.com/questions/43552221/using-awk-sed-to-parse-replace-inline/43552817#43552817 (xml tags replacement)

Search for a String, On Success Search for Nearest Pattern (xml part2)

http://stackoverflow.com/questions/17908555/printing-with-sed-or-awk-a-line-following-a-matching-pattern/17914105#17914105

How to print <x> lines before and <y> lines after <z>th line Print a range of lines techniques & Benchmarks
Also: cat line X to line Y on a huge file

comparing two files line by line using comm and diff: comparing two files line by line

https://stackoverflow.com/help/someone-answers