bash wget - check if file exists at url before downloading

validate.sh

#!/bin/bash

# simple function to check http response code before downloading a remote file
# example usage:
# if `validate_url $url >/dev/null`; then dosomething; else echo "does not exist"; fi


function validate_url(){
  if [[ `wget -S --spider $1  2>&1 | grep 'HTTP/1.1 200 OK'` ]]; then echo "true"; fi
}

hello Team,
Can you tell some solution for random file.
we need to download file daily from https url which is having random name for current data and time .
Starting name is fix and file last part is daily changed due to date and time.
current we use for loop for same but not success output always.
thanks