Unix shells do not traditionally have regex support built-in. Bash and Zsh both do, so if you use the =~ operator to compare a string to a regex, then:

You can get the substrings from the $BASH_REMATCH array in bash.

In Zsh, if the BASH_REMATCH shell option is set, the value is in the $BASH_REMATCH array, else it’s in the $MATCH/$match tied pair of variables (one scalar, the other an array). If the RE_MATCH_PCRE option is set, then the PCRE engine is used, else the system regexp libraries, for an extended regexp syntax match, as per bash.

So, most simply: if you’re using bash:

if [[ "$variable" =~ unquoted.*regex ]]; then

If you’re not using Bash or Zsh, it gets more complicated as you need to use external commands.

Leave a Reply

Your email address will not be published. Required fields are marked *