Timeline for Msys2 bash rejects empty subexpression in regular expression

8 events

when toggle format	what		by	license	comment
yesterday	vote	accept	Peter - Reinstate Monica
yesterday	comment	added	Peter - Reinstate Monica		@cas The real expression is used to check for any of a fixed number of keywords with the same meaning ("n", "no", "none", "0", "false" or, which creates the complication, an empty string ) that may be present in a variable, once, in the beginning of the script. I think the use case is totally fine.
yesterday	comment	added	cas		Is this for just a one-off or occasional regex match in your script? If so, using bash regex matches is fine. If not, if you're using it in, say, a while read loop or a for loop, then you really should rewrite that section of the script to use sed or awk or perl. If regex matches are the majority of the script then rewrite the whole thing in either awk or perl, optionally with a shell wrapper. Use shell for what it's good at, and use other tools for what they're good at.
2 days ago	history	became hot network question
2 days ago	comment	added	Peter - Reinstate Monica		@waltinator Thanks for the pointer; shellcheck finds no issue though.
2 days ago	comment	added	waltinator		Always paste your script into `https://shellcheck.net`, a syntax checker, or install `shellcheck` locally. Make using `shellcheck` part of your development process.
2 days ago	answer	added	Stéphane Chazelas		timeline score: 9
2 days ago	history	asked	Peter - Reinstate Monica	CC BY-SA 4.0