Regular expression to reduce mnemonic to first 3 letters only

Question

Since only the first 3 characters for the English-language mnemonic matter, I prefer to reduce the words to just the first 3 letters only, for cold storage purposes. I would like to do this with a regular expression, to avoid manual errors.

What would be the shortest regular expression to do this? Note that I want a newline at the end. I will post my current solution, looking forward to see a shorter one.

score 4 · Accepted Answer · answered Nov 15 '16 at 10:19

4

You can simply use (\w{3})\w* (example) or (?:^| )(\w{3}) (example), whatever you prefer. There are a lot of other solutions possible as well.

You didn't provide a language, hence my solution to generic regex outside of language implementations should be advantageous.

answered Nov 15 '16 at 10:19

James Cameron

733
4
14

Indeed, I didn't specify a language. I especially like your 1st solution: echo "${MNEMONIC}" | ruby -e "puts ARGF.read.gsub(/(\w{3})\w*/,'\1')". Can't get the other one to work in Ruby though. Thanks also for the regex101.com examples. – dpzz Nov 15 '16 at 18:38

score 3 · Answer 2 · answered Nov 08 '16 at 19:34

3

What I currently have:

echo $(echo "${MNEMONIC}" | tr " " "\n" | sed 's/^$...$.*$/\1/' | tr "\n" " ")

answered Nov 08 '16 at 19:34

dpzz

4,539
3
19
45

Regular expression to reduce mnemonic to first 3 letters only

2 Answers2