One can request only the headers using HTTP HEAD, as option -I in curl(1).
$ curl -I /
Lengthy HTML response bodies are a pain to get in command-line, so I'd like to get only the header as feedback for my POST requests. However, HEAD and POST are two different methods.
How do I get cURL to display only response headers to a POST request?
-D, --dump-header <file>
Write the protocol headers to the specified file.
This option is handy to use when you want to store the headers
that a HTTP site sends to you. Cookies from the headers could
then be read in a second curl invocation by using the -b,
--cookie option! The -c, --cookie-jar option is however a better
way to store cookies.
and
-S, --show-error
When used with -s, --silent, it makes curl show an error message if it fails.
from the man page. so
curl -sS -D - www.acooke.org -o /dev/null
follows redirects, dumps the headers to stdout and sends the data to /dev/null (that's a GET, not a POST, but you can do the same thing with a POST - just add whatever option you're already using for POSTing data)
note the - after the -D which indicates that the output "file" is stdout.
-D takes an argument that says where the output should go. the single dash means it should go to stdout. –
Pino function headers {curl -s -D - $1 -o /dev/null}. –
Cyprio --cacert), or use --insecure flag –
Sheryllshetland $null writes to a file when cLink is installed. –
Caballero -L to follow redirects –
Hawser HTTP/1.1 200 OK), you can pipe it to tail: ` | tail -n +2` –
Parker The other answers require the response body to be downloaded. But there's a way to make a POST request that will only fetch the header:
curl -s -I -X POST http://www.google.com
An -I by itself performs a HEAD request which can be overridden by -X POST to perform a POST (or any other) request and still only get the header data.
GET request and doesn't download the whole response body (or at least doesn't output it). The -s flag is nor necessary. –
Bacitracin GET with POST in above command and it will work as expected. or any other is key there. –
Fluorocarbon POST some data. Curl says: Warning: You can only select one HTTP request method! You asked for both POST Warning: (-d, --data) and HEAD (-I, --head). –
Wording -X HEAD, which won't download the whole file. This is useful if you want to see how large a zip is before fetching it from a server. curl -s -I -X HEAD https://path/to/some/large.zip for example. –
Justus -X HEAD is no reliable solution here. –
Cephalometer Warning: You can only select one HTTP request method! You asked for both POST Warning: (-d, --data) and HEAD (-I, --head). –
Commines -s does become useful once you pipe the output, for example to grep. –
Miamiami -s –
Commines The Following command displays extra informations
curl -X POST http://httpbin.org/post -v > /dev/null
You can ask server to send just HEAD, instead of full response
curl -X HEAD -I http://httpbin.org/
Note: In some cases, server may send different headers for POST and HEAD. But in almost all cases headers are same.
-X, --request correctly, -X HEAD still results in “a ton of data” but there is -I, --head which should results in what you are anticipating. –
Arrowroot -X HEAD and -I are exactly equivalent. –
Litho -X HEAD is that the server might respond differently, since it now receives a HEAD request instead of a GET (or whatever the previous request was) –
Collectanea Warning: Setting custom HTTP method to HEAD with -X/--request may not work the Warning: way you want. Consider using -I/--head instead. –
Debris -vvv - is that super-extra verbose? (can't find anything in docs) –
Monogenic HEAD request SHOULD be identical to the information sent in response to a GET request" [rfc-editor.org/rfc/rfc2616#section-9.4 ], although that may not be actually adhered to, making the proviso necessary, even though it on some level should not be. –
Diskson For long response bodies (and various other similar situations), the solution I use is always to pipe to less, so
curl -i https://api.github.com/users | less
or
curl -s -D - https://api.github.com/users | less
will do the job.
HEAD request to which many servers respond differently. the second issues a GET request which is more like what we are looking for here. –
Azotobacter Maybe it is little bit of an extreme, but I am using this super short version:
curl -svo. <URL>
Explanation:
-v print debug information (which does include headers)
-o. send web page data (which we want to ignore) to a certain file, . in this case, which is a directory and is an invalid destination and makes the output to be ignored.
-s no progress bar, no error information (otherwise you would see Warning: Failed to create the file .: Is a directory)
warning: result always fails (in terms of error code, if reachable or not). Do not use in, say, conditional statements in shell scripting...
-o. instead of -o /dev/null? –
Addiction -o. is used versus -o /dev/null for brevity –
Karakoram curl -svo. <url> && echo foo won’t print foo because -o. make curl return a non-zero (= error) code: curl: (23) Failed writing body. –
Addiction -vo. is shorter than -I ^^ –
Miamiami Much easier – this also follows links.
curl -IL http://shortlinktrack.er/in-the-shadows
-I is an alias of --head, the man page states that it fetch the headers only-L is an alias of --location, the man page states that curl will follow the location header if there is oneWhile the other answers have not worked for me in all situations, the best solution I could find (working with POST as well), taken from here:
curl -vs 'https://some-site.com' 1> /dev/null
headcurl.cmd (windows version)
curl -sSkv -o NUL %* 2>&1
-s, -S, -k, -v (this is about troubleshooting, is it?), %* means [pass on all parameters to this script] (well(https://mcmap.net/q/64416/-redirecting-passed-arguments-to-a-windows-batch-file-duplicate), well usually that's just one parameter: the url you are testingreal-world example (on troubleshooting proxy issues):
C:\depot>headcurl google.ch | grep -i -e http -e cache
Hostname was NOT found in DNS cache
GET HTTP://google.ch/ HTTP/1.1
HTTP/1.1 301 Moved Permanently
Location: http://www.google.ch/
Cache-Control: public, max-age=2592000
X-Cache: HIT from company.somewhere.ch
X-Cache-Lookup: HIT from company.somewhere.ch:1234
Linux version
for your .bash_aliases / .bash_rc:
alias headcurl='curl -sSkv -o /dev/null $@ 2>&1'
-X POST to the passthrough parameters, if you want GET, use GET (i.e. default), as responses may differ. - Unless you do heavy curling in production scripts (not for diagnosis anddevelopment) I don't care about a bit of bandwidth. –
Monogenic The -w, --write-out <format> option can be very helpful. You can get all http headers, or a single one:
$ curl -s -w '%{header_json}' https://httpbin.org/get -o /dev/null
{"date":["Sun, 18 Feb 2024 13:47:12 GMT"],
"content-type":["application/json"],
"content-length":["254"],
"server":["gunicorn/19.9.0"],
"access-control-allow-origin":["*"],
"access-control-allow-credentials":["true"]
}
$ curl -s -w '%header{content-type}' https://httpbin.org/get -o /dev/null
application/json
-D, --dump-header Write the protocol headers to the specified file.
This option is handy to use when you want to store the headers
that a HTTP site sends to you. Cookies from the headers could
then be read in a second curl invocation by using the -b,
--cookie option! The -c, --cookie-jar option is however a better
way to store cookies.
To get only the response header, use the silent output -s along side -i, then output only the first 10 lines using the head command.
curl -si 0:80 | head
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curl -s -D - http://yahoo.com -o nul– Erigena