[SOLVED] sed substitution doubles pattern

vincix · 01-08-2018, 05:49 AM

Instead of substituting the first pattern, it adds another ".host". I don't understand what I'm missing.

Code:

grep host /etc/varnish/default.vcl

Result:

Code:

.host = "172.31.108.183";

Code:

sed -r "s/(.host = \")[0-9]+.[0-9]+.[0-9]+.[0-9]+(\")/\1\192.10.10.10\2/}" /etc/varnish/default.vcl | grep host

Result:

Code:

.host = ".host = "92.10.10.10";

vincix · 01-08-2018, 06:37 AM

Never mind. I was actually trying to escape the first 1 of the "192" group and without realising it, I was actually making the pattern \1 reoccur.

pan64 · 01-08-2018, 08:38 AM

just a comment: . is a special char, you need to protect it: \. (if you want literal .)

vincix · 01-08-2018, 08:42 AM

Yes, I know, you're right. It means any one character.