Can not extract the capture group with neither sed nor grep

Question

I want to extract the value pair from a key-value pair syntax but I can not.
Example I tried:

echo employee_id=1234 | sed \'s/employee_id=\\([0-9]+\\)/\\1/         


        

Answer 1

You are specifically asking for sed, but in case you may use something else - any POSIX-compliant shell can do parameter expansion which doesn't require a fork/subshell:

foo='employee_id=1234'
var=${foo%%=*}
value=${foo#*=}

 

$ echo "var=${var} value=${value}"
var=employee_id value=1234