Using sed to delete a case insensitive matched line

Question

How do I match a case insensitive regex and delete it at the same time

I read that to get case insensitive matches, use the flag "i"

sed -e "/pattern/replace/i" filepath 

and to delete use d

sed -e "/pattern/d" filepath 

I've also read that I could combine multiple flags like 2iw

I'd like to know if sed could combine both i and d I've tried the following but it didn't work

sed -e "/pattern/replace/id" filepath > newfilepath 

Answer 1

For case-insensitive use /I instead of /i.

sed -e "/pattern/Id" filepath 

Answer 2

you can use (g)awk as well.

# print case insensitive awk 'BEGIN{IGNORECASE=1}/pattern/{print}' file  # replace with case insensitive awk 'BEGIN{IGNORECASE=1}/pattern/{gsub(/pattern/,"replacement")}1' file 

OR just with the shell(bash)

#!/bin/bash shopt -s nocasematch while read -r line do     case "$line" in         *pattern* ) echo $line;     esac done <"file"