Curl for Fast Diagnostics

Sometimes, working tech support for shared web hosting, using a web browser is clunky to see what is really going on. curl is the best choice when I need to see exactly what a server is responding with. Here are the commands I use on a regular basis.

curl http://www.programmerq.net/ See the URL, no output if a redirect, no headers
curl -i http://www.programmerq.net/ See the URL with headers
curl -I http://www.programmerq.net/ See only the headers
curl -L http://www.programmerq.net/ See the URL, if it redirects, show the final destination URL
curl -iL http://www.programmerq.net/ See the URL, show headers for each redirected location, show final destination URL
curl -d "name=value" http://www.programmerq.net/ post a form value to url; can repeat option for multiple values
curl -b cookies.txt http://www.programmerq.net/ read cookie data from "cookies.txt"
curl -c cookies.txt http://www.programmerq.net/ write cookie data to "cookies.txt"
curl -b cookies.txt -c cookies.txt http://www.programmerq.net/ read cookie data from and write cookie data to "cookies.txt"
curl -u <username> http://www.programmerq.net/ use username when making the request, password is prompted on command line
watch "curl -s http://www.programmerq.net/" repeat the curl command without spewing speed information