Bash - Find and replace regex with another string

Question

I have the following string libVersion = '1.23.45.6' and I need to replace 1.23.45.6 with 1.23.45.7.

Obviously the version could be any number with similar format (it does not have to be 4 numbers).

I tried to use the following but doesn't work

echo "libVersion = '1.23.45.6'" |sed "s/([0-9\.]+)/1.23.45.7/g"

echo "libVersion = '1.23.45.6'" |sed "s/[0-9.]\+/1.23.45.7/g" — Avinash Raj
– Avinash Raj, Commented Jul 21, 2016 at 11:13
or echo "libVersion = '1.23.45.6'" |sed "s/'[^']*'/'1.23.45.7'/g" — Avinash Raj
– Avinash Raj, Commented Jul 21, 2016 at 11:14
Bingo!!! Please put it in the answer so I can mark as the correct answer — Wins
– Wins, Commented Jul 21, 2016 at 11:15
Actually, you can use the E option with your regex (sed -E "s/([0-9.]+)/1.23.45.7/"). But /g is redundant if you want to replace once and the (...) is redundant since you are not using the captured value. I'd use sed -E "s/[0-9.]+/1.23.45.7/". — Wiktor Stribiżew
– Wiktor Stribiżew, Commented Jul 21, 2016 at 11:17

Avinash Raj · Accepted Answer · 2016-07-21 11:25:14Z

3

Basic sed, ie sed without any arguments uses BRE (Basic Regular Expression). In BRE, you have to escape +, to bring the power of regex + which repeats the previous token one or more times, likewise for the capturing groups \(regex\)

echo "libVersion = '1.23.45.6'" | sed "s/[0-9.]\+/1.23.45.7/"

You may also use a negated char class to replace all the chars exists within single quotes.

echo "libVersion = '1.23.45.6'" | sed "s/'[^']*'/'1.23.45.7'/"

Since the replacement should occur only one time, you don't need a g global modifier.

answered Jul 21, 2016 at 11:25

Avinash Raj

175k32 gold badges247 silver badges289 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Avinash Raj Over a year ago

@wiktor you kidding me :P

Collectives™ on Stack Overflow

Bash - Find and replace regex with another string

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related