How can I see the request headers made by curl when sending a request to the server?
CurlCurl Problem Overview
I want to see the request headers made by curl when I am sending a request to the server. How can I check that?
Curl Solutions
Solution 1 - Curl
I think curl --verbose/-v is the easiest. It will spit out the request headers (lines prefixed with '>') without having to write to a file:
$ curl -v -I -H "Testing: Test header so you see this works" http://stackoverflow.com/
* About to connect() to stackoverflow.com port 80 (#0)
* Trying 69.59.196.211... connected
* Connected to stackoverflow.com (69.59.196.211) port 80 (#0)
> HEAD / HTTP/1.1
> User-Agent: curl/7.16.3 (i686-pc-cygwin) libcurl/7.16.3 OpenSSL/0.9.8h zlib/1.2.3 libssh2/0.15-CVS
> Host: stackoverflow.com
> Accept: */*
> Testing: Test header so you see this works
>
< HTTP/1.0 200 OK
...
Solution 2 - Curl
The question did not specify if command line command named curl was meant or the whole cURL library.
The following PHP code using cURL library uses first parameter as HTTP method (e.g. "GET", "POST", "OPTIONS") and second parameter as URL.
<?php
$ch = curl_init();
$f = tmpfile(); # will be automatically removed after fclose()
curl_setopt_array($ch, array(
CURLOPT_CUSTOMREQUEST => $argv[1],
CURLOPT_URL => $argv[2],
CURLOPT_RETURNTRANSFER => 1,
CURLOPT_FOLLOWLOCATION => 0,
CURLOPT_VERBOSE => 1,
CURLOPT_HEADER => 0,
CURLOPT_CONNECTTIMEOUT => 5,
CURLOPT_TIMEOUT => 30,
CURLOPT_STDERR => $f,
));
$response = curl_exec($ch);
fseek($f, 0);
echo fread($f, 32*1024); # output up to 32 KB cURL verbose log
fclose($f);
curl_close($ch);
echo $response;
Example usage:
php curl-test.php OPTIONS https://google.com
Note that the results are nearly identical to following command line
curl -v -s -o - -X OPTIONS https://google.com
Solution 3 - Curl
The --trace-ascii option to curl will show the request headers, as well as the response headers and response body.
For example, the command
curl --trace-ascii curl.trace http://www.google.com/
produces a file curl.trace that starts as follows:
== Info: About to connect() to www.google.com port 80 (#0)
== Info: Trying 209.85.229.104... == Info: connected
== Info: Connected to www.google.com (209.85.229.104) port 80 (#0)
=> Send header, 145 bytes (0x91)
0000: GET / HTTP/1.1
0010: User-Agent: curl/7.16.3 (powerpc-apple-darwin9.0) libcurl/7.16.3
0050: OpenSSL/0.9.7l zlib/1.2.3
006c: Host: www.google.com
0082: Accept: */*
008f:
It also got a response (a 302 response, to be precise but irrelevant) which was logged.
If you only want to save the response headers, use the --dump-header option:
curl -D file url
curl --dump-header file url
If you need more information about the options available, use curl --help | less (it produces a couple hundred lines of output but mentions a lot of options). Or find the manual page where there is more explanation of what the options mean.
Solution 4 - Curl
The only way I managed to see my outgoing headers (curl with php) was using the following options:
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLINFO_HEADER_OUT, true);
Getting your debug info:
$data = curl_exec($ch);
var_dump($data);
var_dump(curl_getinfo($ch));
Solution 5 - Curl
curl --trace-ascii {filename} or use a single dash instead of file name to get it sent to stdout:
curl --trace-ascii - {URL}
CURLOPT_DEBUGFUNCTION if you're using libcurl
This shows you everything curl sends and receives, with some extra info thrown in.
Solution 6 - Curl
I tried the answers here and found that the most useful and easiest one is not listed as an answer yet, but it is:
curl -v https://example.com/path
This prints out the REQUEST headers as well as the RESPONSE headers plus other useful such as the SSL cert and whether an existing TCP connection was reused. the -v flag can be combined with other flags, of course, such as to follow redirects and prompt for HTTP authentication:
curl -vL --user my_username https://example.com/path
Hope this helps.
Solution 7 - Curl
A command like the one below will show three sections: request headers, response headers and data (separated by CRLF). It avoids technical information and syntactical noise added by curl.
curl -vs www.stackoverflow.com 2>&1 | sed '/^* /d; /bytes data]$/d; s/> //; s/< //'
The command will produce the following output:
GET / HTTP/1.1
Host: www.stackoverflow.com
User-Agent: curl/7.54.0
Accept: */*
HTTP/1.1 301 Moved Permanently
Content-Type: text/html; charset=UTF-8
Location: https://stackoverflow.com/
Content-Length: 149
Accept-Ranges: bytes
Date: Wed, 16 Jan 2019 20:28:56 GMT
Via: 1.1 varnish
Connection: keep-alive
X-Served-By: cache-bma1622-BMA
X-Cache: MISS
X-Cache-Hits: 0
X-Timer: S1547670537.588756,VS0,VE105
Vary: Fastly-SSL
X-DNS-Prefetch-Control: off
Set-Cookie: prov=e4b211f7-ae13-dad3-9720-167742a5dff8; domain=.stackoverflow.com; expires=Fri, 01-Jan-2055 00:00:00 GMT; path=/; HttpOnly
<head><title>Document Moved</title></head>
<body><h1>Object Moved</h1>This document may be found <a HREF="https://stackoverflow.com/">here</a></body>
Description:
-vs- add headers (-v) but remove progress bar (-s)2>&1- combine stdout and stderr into single stdoutsed- edit response produced by curl using the commands below/^* /d- remove lines starting with '* ' (technical info)/bytes data]$/d- remove lines ending with 'bytes data]' (technical info)s/> //- remove '> ' prefixs/< //- remove '< ' prefix
Solution 8 - Curl
I know this is a little late, but my favoured method for doing this is netcat, as you get exactly what curl sent; this can differ from the --trace or --trace-ascii options which won't show non-ASCII characters properly (they just show as dots or need to be decoded).
You can do this as very easily by opening two terminal windows, in the first type:
nc -l localhost 12345
This opens a listening process on port 12345 of your local machine.
In the second terminal window enter your curl command, for example:
curl --form 'foo=bar' localhost:12345
In the first terminal window you will see exactly what curl sent in the request.
Now of course nc won't send anything in response (unless you type it in yourself), so you will need to interrupt the curl command (control-c) and repeat the process for each test.
However, this is a useful option for simply debugging your request, as you're not involving a round-trip anywhere, or producing bogus, iterative requests somewhere until you get it right; once you're happy with the command, simply redirect it to a valid URL and you're good to go.
You can do the same for any cURL library as well, simply edit your request to point to the local nc listener until you're happy with it.
Solution 9 - Curl
dump the headers in one file and the payload of the response in a different file
curl -k -v -u user:pass "url" --trace-ascii headers.txt >> response.txt
Solution 10 - Curl
curl -s -v -o/dev/null -H "Testheader: test" http://www.example.com</pre>
You could also use curl -s -v -o/dev/null -H "Testheader: test" http://www.example.com</pre>
You could also use -I option if you want to send a HEAD request and not a GET request.
option if you want to send a HEAD request and not a GET request.
Solution 11 - Curl
Here is my http client in php to make post queries with cookies included:
function http_login_client($url, $params = "", $cookies_send = "" ){
// Vars
$cookies = array();
$headers = getallheaders();
// Perform a http post request to $ur1 using $params
$ch = curl_init($url);
$options = array( CURLOPT_POST => 1,
CURLINFO_HEADER_OUT => true,
CURLOPT_POSTFIELDS => $params,
CURLOPT_RETURNTRANSFER => 1,
CURLOPT_HEADER => 1,
CURLOPT_COOKIE => $cookies_send,
CURLOPT_USERAGENT => $headers['User-Agent']
);
curl_setopt_array($ch, $options);
$response = curl_exec($ch);
/// DEBUG info echo $response; var_dump (curl_getinfo($ch)); ///
// Parse response and read cookies
preg_match_all('/^Set-Cookie: (.*?)=(.*?);/m', $response, $matches);
// Build an array with cookies
foreach( $matches[1] as $index => $cookie )
$cookies[$cookie] = $matches[2][$index];
return $cookies;
} // end http_login_client
Solution 12 - Curl
You can see it by using -iv
$> curl -ivH "apikey:ad9ff3d36888957" --form "file=@/home/mar/workspace/images/8.jpg" --form "language=eng" --form "isOverlayRequired=true" https://api.ocr.space/Parse/Image
Solution 13 - Curl
Solution 14 - Curl
Make a sample request to https://http-tools.appspot.com/reflect-http-request/some-unique-id and check what this request contains (request header, request body, request parameters) by its corresponding finder url https://http-tools.appspot.com/reflect-http-request-finder/some-unique-id. You can use any string instead of some-unique-id, check out https://http-tools.appspot.com for more details.
Solution 15 - Curl
You can dump headers directly to stdout by using "-" as the filename - so for example to see headers and content, and follow redirects, all in one output:
curl -L -D - -s [url]