How can I see the request headers made by curl when sending a request to the server

Question

I want to see the request headers made by curl when I am sending a request to the server  How can I check that

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

You can see it by using -iv    gt  curl  -ivH  apikey ad9ff3d36888957  --form   file   home mar workspace images 8 jpg  --form  language eng  --form  isOverlayRequired true  https   api ocr space Parse Image

User · Answer

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     lt  php  ch   curl init     f   tmpfile      will be automatically removed after fclose   curl setopt array  ch  array      CURLOPT CUSTOMREQUEST    gt   argv 1       CURLOPT URL              gt   argv 2        CURLOPT RETURNTRANSFER   gt  1      CURLOPT FOLLOWLOCATION   gt  0      CURLOPT VERBOSE          gt  1      CURLOPT HEADER           gt  0      CURLOPT CONNECTTIMEOUT   gt  5      CURLOPT TIMEOUT          gt  30      CURLOPT STDERR           gt   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

User · Answer

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 gt  amp 1   sed       d   bytes data   d  s  gt      s  lt        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   lt head gt  lt title gt Document Moved lt  title gt  lt  head gt   lt body gt  lt h1 gt Object Moved lt  h1 gt This document may be found  lt a HREF  https   stackoverflow com   gt here lt  a gt  lt  body gt    Description    -vs - add headers  -v  but remove progress bar  -s  2 gt  amp 1 - combine stdout and stderr into single stdout sed - 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  gt     - remove      prefix s  lt     - remove   lt    prefix

User · Answer

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

User · Answer

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   gt  1                          CURLINFO HEADER OUT   gt  true                          CURLOPT POSTFIELDS   gt   params                          CURLOPT RETURNTRANSFER   gt  1                          CURLOPT HEADER   gt  1                          CURLOPT COOKIE   gt   cookies send                          CURLOPT USERAGENT   gt   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   gt   cookie            cookies  cookie     matches 2   index        return  cookies       end http login client

User · Answer

I think curl --verbose -v is the easiest  It will spit out the request headers  lines prefixed with   gt    without having to write to a file    curl -v -I -H  quot Testing  Test header so you see this works quot  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   gt  HEAD   HTTP 1 1  gt  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  gt  Host  stackoverflow com  gt  Accept       gt  Testing  Test header so you see this works  gt   lt  HTTP 1 0 200 OK

User · Answer

You can use wireshark or tcpdump to look on any network traffic  http too

User · Answer

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    gt  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

User · Answer

curl -s -v -o dev null -H  Testheader  test  http   www example com  You could also use -I option if you want to send a HEAD request and not a GET request

User · Answer

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  gt  gt  response txt

[curl] How can I see the request headers made by curl when sending a request to the server?

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