#!/bin/bash
A="/CLIENT_IPADDR:23.4.28.2 /CLIENT_LOGIN:xdfmb1d /MXJ_C"
B=$(echo "$A" | awk 'match($0,/\/CLIENT_LOGIN:[^[:space:]]+/){print substr($0,RSTART+14,RLENGTH-14)}')
echo "$B"
IyEvYmluL2Jhc2gKQT0iL0NMSUVOVF9JUEFERFI6MjMuNC4yOC4yIC9DTElFTlRfTE9HSU46eGRmbWIxZCAvTVhKX0MiCkI9JChlY2hvICIkQSIgfCBhd2sgJ21hdGNoKCQwLC9cL0NMSUVOVF9MT0dJTjpbXls6c3BhY2U6XV0rLyl7cHJpbnQgc3Vic3RyKCQwLFJTVEFSVCsxNCxSTEVOR1RILTE0KX0nKQplY2hvICIkQiI=