sed command - Naming captured group

Question

Back references (e.g. "\3") are not very practical when you are writing a substitution command using sed with many captured groups (e.g. to convert an access log line to another format).

Beside, if you add another capture group at the beginning, you have to update the substitution pattern too, i.e. adding +1 to all back references.

So, is there a way to name captured group in sed command instead of using back-references?

Answer 1

sed does not support named backreferences.

Perl supports them, and you may specify any amount of named capturing groups with the same name in the pattern:

perl -pe 's/(?<i>b)ash|(?<i>sl)ash|(?<i>m)ash/$+{i}ong/g' <<< "bash slash mash"

Result:

bong slong mong

See demo