Using sed command to search and replace IP address
" If your version of sed supports extended regular expressions (the -r option), you could do something like this (which is similar to what you have in your grep statement). Also note $newip is outside the single quotes to allow the shell to replace it.
sed -r 's/(\b[0-9]{1,3}\.){3}[0-9]{1,3}\b'/$newip/
BTW this solution still matches strings that do not represent IP addresses. See this site under IP Adresses for more complex solutions."
มีข้อเสียคือมัน replace pattern เลข.เลข.เลข.เลข ไม่ได้สนใจว่าเป็น IP address ที่ถูกต้องหรือไม่
from: StackOverflow using-sed-to-search-and-replace-an-ip-address-in-a-file
“The only true wisdom is knowing that you know nothing.”