Literally copying this post/note from a blog post by Nate Good http://nategood.com/quickly-add-and-edit-cookies-in-chrome
If you want to inset a cookie into a website request in Google Chrome, you can do it by launching developer tools (F12 in Windows) and typing the following in the console
javascript:document.cookie="myCookieName=myCookieValue"
If you want to search for a pattern at the end of a line, you can use
tail -f logfile | grep -v "0$"
breaking down the commands
tail -f : standard tail command. Continuous output to console as the file grows (or until it ends)
grep -v : -v command forces grep to show content that doesn’t match pattern
0$ : This regex is specifically looking for a 0 at the end of the line, which is denoted by $.
varnishlog, one of the tools provided with varnish cache, uses VSL Query Expressions (https://www.varnish-cache.org/docs/trunk/reference/vsl-query.html) to provide some powerful insights into the requests and responses.
Here is a how you can use varnishlog to show all client requests that are ending up with a 404 response.
sudo varnishlog -g request -i ReqURL -q "BerespStatus != 200"
Technically, this particular query shows all client requests with a response other than 200.
Breaking down the commands
-g request : shows all entries related to the request
-i ReqURL : forces varnishlog to only display the Requesting URL
-q “BerespStatus != 200” : query filter to only match non 200 responses. Note that the query has to be enclosed in “”.
