https://buttondown.email/hillelwayne/archive/why-do-regexes-use-and-as-line-anchors/
Last week I fell into a bit of a rabbit hole: why do regular expressions use $ and ^ as line anchors?1
This talk brings up that they first appeared in Ken Thompson's port of the QED text editor. In his manual he writes: b) "^" is a regular expression which matches character at the beginning of a line.
c) "$" is a regular expression which matches character before the character (usually at the end of a line)
QED was the precursor to ed, which was instrumental in popularizing regexes, so a lot of its design choices stuck.
Okay, but then why did Ken Thompson choose those characters?
(Score: 4, Funny) by Rosco P. Coltrane on Wednesday March 27 2024, @11:44PM (1 child)
You kids had it easy. When I learned programming, we had to punch the cards with a hammer and a chisel!
(Score: 2) by turgid on Thursday March 28 2024, @09:43PM
In my day, we had Hovis.
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].