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bashglob

Extract different kinds of protocol from URL

I have the following URLs with different types of protocol:

URL=https://example.com
URL=ftp://example.com
URL=ssh://example.com
URL=///filestore/storage

I'm using echo ${URL%://*} to get protocol, but for /// it doesn't work, can't apply multiple regex, please help

Solution

  • You can use this extended glob matching:

    "${url%?(:)//*}"

    Where ?(:) matches an optional : using extended globbing followed by // and that is followed by any number of characters as per glob matching in shell.

    Code:

    for url in 'https://example.com' 'ftp://example.com' 'ssh://example.com' '///filestore/storage'; do
   echo "${url%?(:)//*}"
done

https
ftp
ssh
/

    PS: On BASH versions < 4 use shopt -s extglob before this code.