mirror of
https://github.com/moparisthebest/curl
synced 2024-12-22 16:18:48 -05:00
124 lines
4.4 KiB
Plaintext
124 lines
4.4 KiB
Plaintext
Updated: July 3, 2012 (http://curl.haxx.se/docs/http-cookies.html)
|
|
_ _ ____ _
|
|
___| | | | _ \| |
|
|
/ __| | | | |_) | |
|
|
| (__| |_| | _ <| |___
|
|
\___|\___/|_| \_\_____|
|
|
|
|
|
|
HTTP Cookies
|
|
|
|
1. HTTP Cookies
|
|
1.1 Cookie overview
|
|
1.2 Cookies saved to disk
|
|
1.3 Cookies with curl the command line tool
|
|
1.4 Cookies with libcurl
|
|
1.5 Cookies with javascript
|
|
|
|
==============================================================================
|
|
|
|
1. HTTP Cookies
|
|
|
|
1.1 Cookie overview
|
|
|
|
HTTP cookies are pieces of 'name=contents' snippets that a server tells the
|
|
client to hold and then the client sends back those the server on subsequent
|
|
requests to the same domains/paths for which the cookies were set.
|
|
|
|
Cookies are either "session cookies" which typically are forgotten when the
|
|
session is over which is often translated to equal when browser quits, or
|
|
the cookies aren't session cookies they have expiration dates after which
|
|
the client will throw them away.
|
|
|
|
Cookies are set to the client with the Set-Cookie: header and are sent to
|
|
servers with the Cookie: header.
|
|
|
|
For a very long time, the only spec explaining how to use cookies was the
|
|
original Netscape spec from 1994: http://curl.haxx.se/rfc/cookie_spec.html
|
|
|
|
In 2011, RFC6265 (https://www.ietf.org/rfc/rfc6265.txt) was finally published
|
|
and details how cookies work within HTTP.
|
|
|
|
1.2 Cookies saved to disk
|
|
|
|
Netscape once created a file format for storing cookies on disk so that they
|
|
would survive browser restarts. curl adopted that file format to allow
|
|
sharing the cookies with browsers, only to see browsers move away from that
|
|
format. Modern browsers no longer use it, while curl still does.
|
|
|
|
The netscape cookie file format stores one cookie per physical line in the
|
|
file with a bunch of associated meta data, each field separated with
|
|
TAB. That file is called the cookiejar in curl terminology.
|
|
|
|
When libcurl saves a cookiejar, it creates a file header of its own in which
|
|
there is a URL mention that will link to the web version of this document.
|
|
|
|
1.3 Cookies with curl the command line tool
|
|
|
|
curl has a full cookie "engine" built in. If you just activate it, you can
|
|
have curl receive and send cookies exactly as mandated in the specs.
|
|
|
|
Command line options:
|
|
|
|
-b, --cookie
|
|
|
|
tell curl a file to read cookies from and start the cookie engine, or if
|
|
it isn't a file it will pass on the given string. -b name=var works and so
|
|
does -b cookiefile.
|
|
|
|
-j, --junk-session-cookies
|
|
|
|
when used in combination with -b, it will skip all "session cookies" on
|
|
load so as to appear to start a new cookie session.
|
|
|
|
-c, --cookie-jar
|
|
|
|
tell curl to start the cookie engine and write cookies to the given file
|
|
after the request(s)
|
|
|
|
1.4 Cookies with libcurl
|
|
|
|
libcurl offers several ways to enable and interface the cookie engine. These
|
|
options are the ones provided by the native API. libcurl bindings may offer
|
|
access to them using other means.
|
|
|
|
CURLOPT_COOKIE
|
|
|
|
Is used when you want to specify the exact contents of a cookie header to
|
|
send to the server.
|
|
|
|
CURLOPT_COOKIEFILE
|
|
|
|
Tell libcurl to activate the cookie engine, and to read the initial set of
|
|
cookies from the given file. Read-only.
|
|
|
|
CURLOPT_COOKIEJAR
|
|
|
|
Tell libcurl to activate the cookie engine, and when the easy handle is
|
|
closed save all known cookies to the given cookiejar file. Write-only.
|
|
|
|
CURLOPT_COOKIELIST
|
|
|
|
Provide detailed information about a single cookie to add to the internal
|
|
storage of cookies. Pass in the cookie as a HTTP header with all the
|
|
details set, or pass in a line from a netscape cookie file. This option
|
|
can also be used to flush the cookies etc.
|
|
|
|
CURLINFO_COOKIELIST
|
|
|
|
Extract cookie information from the internal cookie storage as a linked
|
|
list.
|
|
|
|
1.5 Cookies with javascript
|
|
|
|
These days a lot of the web is built up by javascript. The webbrowser loads
|
|
complete programs that render the page you see. These javascript programs
|
|
can also set and access cookies.
|
|
|
|
Since curl and libcurl are plain HTTP clients without any knowledge of or
|
|
capability to handle javascript, such cookies will not be detected or used.
|
|
|
|
Often, if you want to mimic what a browser does on such web sites, you can
|
|
record web browser HTTP traffic when using such a site and then repeat the
|
|
cookie operations using curl or libcurl.
|