Useful curl switches

In a similar vein to my previous post I want to have a place where I keep track of all the useful curl switches.

• • -L follow redirects
  • -s silent
  • -v verbose
  • -o output file
    
    # download a file silently and save to the name specified; follow any redirects curl -sL "https://something/latest?version=3&os=linux" -o something.linux.tar.gz

    1 2	# download a file silently and save to the name specified; follow any redirects curl -sL "https://something/latest?version=3&os=linux" -o something.linux.tar.gz

  • -H (or --header) send custom headers
    
    curl -H "Accept: text/html" http://something

    1	curl -H "Accept: text/html" http://something

  • -d (or --data) send data (inline, or a file specified by @<filename>)
    
    # Send data inline curl -H "Content-Type: application/json" \ -d "{\"value\":\"node JS\"}" http://something # Send data in a file instead curl -H "Content-Type: application/json" \ -d @file.json http://something

    1 2 3 4 5 6 7

    # Send data inline curl -H "Content-Type: application/json" \ -d "{\"value\":\"node JS\"}" http://something   # Send data in a file instead curl -H "Content-Type: application/json" \ -d @file.json http://something

  • --data-binary same as above for binary files
  • -X "METHOD" to make a request of custom method
    
    curl localhost:2019/load \ -X POST \ -H "Content-Type: application/json" \ -d @caddy.json

    1 2 3 4

    curl localhost:2019/load \ -X POST \ -H "Content-Type: application/json" \ -d @caddy.json

• -k skip any SSL checks (useful for self-signed certs)

Request types:

• • By default curl does a GET request.
  • -d or -F makes it a POST request.
  • -I generates a HEAD (use this to view headers only)
  • -T sends a PUT
  • -X "METHOD" for a custom method (which could be GET or POST etc.)
    
    curl -X GET -H 'X-NSONE-Key: $API_KEY' https://api.nsone.net/v1/zones

    1	curl -X GET -H 'X-NSONE-Key: $API_KEY' https://api.nsone.net/v1/zones

  View Response Headers:

  curl -s -D - -o /dev/null http://example.com

  1	curl -s -D - -o /dev/null http://example.com

  • -s : Avoid showing progress bar
  • -D - : Dump headers to a file, but - sends it to stdout
  • -o /dev/null : Ignore response body

  This is better than -I as it doesn’t send a HEAD request, which can produce different results.

It’s better than -v because you don’t need so many hacks to un-verbose it. Thanks SO.

Finding where a Url redirects to:

• -L follow redirects
• -s silent
• -o output file (to /dev/null in this case as we don’t care for the output)
• -w what to output after completion (in this case url_effective followed by two new lines as I like to space things out)

Thanks again, SO.