Why does BASH_REMATCH not work for a quoted regular expression?

Question

The code is like this:

#!/bin/bash
if [[ foobarbletch =~ \'foo(bar)bl(.*)\' ]]
 then
     echo \"The regex matches!\"
     echo $BASH_REMATCH
     echo ${BAS         


        

Answer 1

You can also assign the quoted regexp to a variable:

#!/bin/bash

x='foobarbletch'

foobar_re='foo(bar)bl(.*)'

if [[ $x =~ $foobar_re ]] ; then
    echo The regex matches!
    echo ${BASH_REMATCH[*]}
    echo ${BASH_REMATCH[1]}
    echo ${BASH_REMATCH[2]}
fi

This not only supports simple quoting but gives the regexp a name which can help readability.