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Excluding the first 3 characters of a string using regex

Given any string in bash, e.g flaccid, I want to match all characters in the string but the first 3 (in this case I want to exclude "fla" and match only "ccid"). The regex also needs to work in sed.

I have tried positive look behind and the following regex expressions (as well as various other unsuccessful ones):

^.{3}+([a-z,A-Z]+)
sed -r 's/(?<=^....)(.[A-Z]*)/,/g'

Google hasn't been very helpful as it only produce results like "get first 3 characters .."

Thanks in advance!

Solution

  • If you want to get all characters but the first 3 from a string, you can use cut:

    str="flaccid"
cut -c 4- <<< "$str"

    or bash variable subsitution:

    str="flaccid"
echo "${str:3}"

    That will strip the first 3 characters out of your string.