check wordpress version

#!/bin/bash
#checking wordpress version
 check(){
 if [[ `curl -s "${s}/feed/"` =~ 'https://wordpress.org/?v=' ]]
 then
 grep=`curl -s "${s}/feed/" | grep -Po '(?<=press.org/)[^"]*(</generator>)' | tr -d '?v=' | tr -d '</generator>'`
 echo "Version is ${grep}"
 echo "${s}">>$grep.txt
else
    echo "can't get version"
fi
 }
 for s in `cat $1`; do
  echo "$s"
  check $s
  done