#!/bin/bash
HTTPD=`curl -A "Web Check" -sL --connect-timeout 3 -w "%{http_code}n" "http://127.0.0.1" -o /dev/null`
until [ "$HTTPD" == "200" ]; do
    printf '.'
    sleep 5
    service nginx restart
done

or

while [ "$HTTPD" != "200" ];
do
   service nginx restart
   sleep 5
   if [ "$HTTPD" == "200" ];then
        break;
   else
        service nginx restart
   fi
done

#!/bin/bash

HTTPD=`curl -A "Web Check" -sL --connect-timeout 3 -w "%{http_code}n" "http://127.0.0.1" -o /dev/null`
until [ "$HTTPD" == "200" ]; do
    printf '.'
    sleep 3
    service nginx restart
    HTTPD=`curl -A "Web Check" -sL --connect-timeout 3 -w "%{http_code}n" "http://127.0.0.1" -o /dev/null`
done