ibrowse/README

ibrowse is a HTTP client. The following are a list of features.
        - RFC2616 compliant (AFAIK) 
        - supports GET, POST, OPTIONS, HEAD, PUT, DELETE, TRACE, 
          MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, MOVE and COPY
        - Understands HTTP/0.9, HTTP/1.0 and HTTP/1.1
        - Understands chunked encoding
        - Can generate requests using Chunked Transfer-Encoding
        - Pools of connections to each webserver
        - Pipelining support
        - Download to file
        - Asynchronous requests. Responses are streamed to a process
        - Basic authentication
        - Supports proxy authentication
        - Can talk to Secure webservers using SSL
        - any other features in the code not listed here :)

ibrowse is available under two different licenses. LGPL or the BSD license.

Comments to : Chandrashekhar.Mullaparthi@gmail.com

Version : 2.0.0

Latest version : git://github.com/cmullaparthi/ibrowse.git

CONTRIBUTIONS & CHANGE HISTORY
==============================
22-09-2010 - * Added option preserve_chunked_encoding. This allows the caller to get
               the raw HTTP response when the Transfer-Encoding is Chunked. This feature
               was requested by Benoit Chesneau who wanted to write a HTTP proxy using
               ibrowse.
             * Fixed bug with the {stream_to, {Pid, once}} option. Bug report and lot
               of help from Filipe David Manana. Thank you Filipe.
             * The {error, conn_failed} and {error, send_failed} return values are
               now of the form {error, {conn_failed, Err}} and 
               {error, {send_failed, Err}}. This is so that the specific socket error
               can be returned to the caller. I think it looks a bit ugly, but that
               is the best compromise I could come up with.
             * Added application configuration parameters default_max_sessions and
               default_max_pipeline_size. These were previously hard coded to 10.
             * Versioning of ibrowse now follows the Semantic Versioning principles.
               See http://semver.org. Thanks to Anthony Molinaro for nudging me in
               this direction.
             * The connect_timeout option now only applies to the connection setup
               phase. In previous versions, the time taken to setup the connection
               was deducted from the specified timeout value for the request.

17-07-2010 - * Merged change made by Filipe David Manana to use the base64
               module for encoding/decoding. 

11-06-2010 - * Removed use of deprecated concat_binary. Patch supplied by
               Steve Vinoski

10-06-2010 - * Fixed bug in https requests not going via the proxy

12-05-2010 - * Added support for the CONNECT method to tunnel HTTPS through
               a proxy. When a https URL is requested through a proxy, 
               ibrowse will automatically use the CONNECT method to first
               setup a tunnel through the proxy. Once this succeeds, the 
               actual request is dispatched. Successfully tested with the 
               new SSL implementation in R13B-03
             * Added SSL support for direct connections. 
               See ibrowse:spawn_worker_process/1 and 
               ibrowse:spawn_link_worker_process/1
             * Added option to return raw status line and raw unparsed headers

23-04-2010 - * Fixes to URL parsing by Karol Skocik

08-11-2009 - * Added option headers_as_is

04-10-2009 - * Patch from Kostis Sagonas to cleanup some code and suppress
               dialyzer warnings

24-09-2009 - * When a filename was supplied with the 'save_response_to_file' 
               option, the option was being ignored. Bug report from 
               Adam Kocoloski

05-09-2009 - * Introduced option to allow caller to set socket options.

29-07-2009 - * The ETS table created for load balancing of requests was not
               being deleted which led to the node not being able to create
               any more ETS tables if queries were made to many number of 
               webservers. ibrowse now deletes the ETS table it creates once the
               last connection to a webserver is dropped. 
               Reported by Seth Falcon.
             * Spurious data being returned at end of body in certain cases of
               chunked encoded responses from the server. 
               Reported by Chris Newcombe.

03-07-2009 - Added option {stream_to, {Pid, once}} which allows the caller
             to control when it wants to receive more data. If this option
             is used, the call ibrowse:stream_next(Req_id) should be used
             to get more data.
           - Patch submitted by Steve Vinoski to remove compiler warnings
             about the use of obsolete guards

29-06-2009 - * Fixed following issues reported by Oscar Hellstr�m
               - Use {active, once} instead of {active, true}
               - Fix 'dodgy' timeout handling
               - Use binaries internally instead of lists to reduce memory
                 consumption on 64 bit platforms. The default response format
                 is still 'list' to maintain backwards compatibility. Use the
                 option {response_format, binary} to get responses as binaries.
             * Fixed chunking bug (reported by Adam Kocoloski)
             * Added new option {inactivity_timeout, Milliseconds} to timeout
               requests if no data is received on the link for the specified
               interval. Useful when responses are large and links are flaky.
             * Added ibrowse:all_trace_off/0 to turn off all tracing
             * Change to the way responses to asynchronous requests are
               returned. The following messages have been removed.
                * {ibrowse_async_response, Req_id, {chunk_start, Chunk_size}}
                 * {ibrowse_async_response, Req_id, chunk_end}
             * Fixed Makefiles as part of Debian packaging 
               (thanks to Thomas Lindgren)
             * Moved repository from Sourceforge to Github

11-06-2009 - * Added option to control size of streamed chunks. Also added 
               option for the client to receive responses in binary format.

21-05-2008 - * Fixed bug in reading some options from the ibrowse.conf file.
               Reported by Erik Reitsma on the erlyaws mailing list
             * Fixed bug when cleaning up closing connections

27-03-2008 - * Major rewrite of the load balancing feature. Additional module,
               ibrowse_lb.erl, introduced to achieve this.
             * Can now get a handle to a connection process which is not part of
               the load balancing pool. Useful when an application is making
               requests to a webserver which are time consuming (such as 
               uploading a large file). Such requests can be put on a separate
               connection, and all other smaller/quicker requests can use the
               load balancing pool. See ibrowse:spawn_worker_process/2 and
               ibrowse:spawn_link_worker_process/2
             * Ram Krishnan sent a patch to enable a client to send a lot of
               data in a request by providing a fun which is invoked by the
               connection handling process. This fun can fetch the data from 
               any where. This is useful when trying to upload a large file
               to a webserver.
             * Use the TCP_NODELAY option on every socket by default
             * Rudimentary support for load testing of ibrowse. Undocumented, 
               but see ibrowse_test:load_test/3. Use the source, Luke!
             * New function ibrowse:show_dest_status/2 to view state of
               connections/pipelines to a web server

20-02-2008 - Ram Krishnan sent another patch for another hidden bug in the
             save_response_to_file feature.

07-02-2008 - Ram Krishnan (kriyative _at_ gmail dot com) sent a simple patch to
             enable specifying the filename in the save_response_to_file option.
             When testing the patch, I realised that my original implementation
             of this feature was quite flaky and a lot of corner cases were 
             not covered.  Fixed all of them. Thanks Ram!

17-10-2007 - Matthew Reilly (matthew dot reilly _at_ sipphone dot com) 
             sent a bug report and a fix. If the chunk trailer spans two TCP 
             packets, then ibrowse fails to recognise that the chunked transfer
             has ended.

29-08-2007 - Bug report by Peter Kristensen(ptx _at_ daimi dot au dot dk). 
             ibrowse crashes when the webserver returns just the Status line 
             and nothing else.

28-06-2007 - Added host_header option to enable connection to secure sites
             via stunnel

20-04-2007 - Geoff Cant sent a patch to remove URL encoding for digits in
             ibrowse_lib:url_encode/1.
             ibrowse had a dependency on the inets application because the 
             ibrowse_http_client.erl invoked httpd_util:encode_base64/1. This
             dependency is now removed and the encode_base64/1 has been 
             implemented in ibrowse_lib.erl

06-03-2007 -  Eric Merritt sent a patch to support WebDAV requests.

12-01-2007 -  Derek Upham sent in a bug fix. The reset_state function was not
              behaving correctly when the transfer encoding was not chunked.

13-11-2006 -  Youns Hafri reported a bug where ibrowse was not returning the 
                temporary filename when the server was closing the connection 
                after sending the data (as in HTTP/1.0).
              Released ibrowse under the BSD license

12-10-2006 -  Chris Newcombe reported bug in dealing with requests where no 
              body is expected in the response. The first request would succeed
              and the next request would hang.

24-May-2006 - Sean Hinde reported a bug. Async responses with pipelining was 
              returning the wrong result.

08-Dec-2005 - Richard Cameron (camster@citeulike.org). Patch to ibrowse to
              prevent port number being included in the Host header when port
              80 is intended.

22-Nov-2005 - Added ability to generate requests using the Chunked 
              Transfer-Encoding.

08-May-2005 - Youns Hafri made a CRUX LINUX port of ibrowse.
              http://yhafri.club.fr/crux/index.html

Here are some usage examples. Enjoy!

5> ibrowse:start().
{ok,<0.94.0>}

%% A simple GET
6> ibrowse:send_req("http://intranet/messenger/", [], get).
{ok,"200",
    [{"Server","Microsoft-IIS/5.0"},
     {"Content-Location","http://intranet/messenger/index.html"},
     {"Date","Fri, 17 Dec 2004 15:16:19 GMT"},
     {"Content-Type","text/html"},
     {"Accept-Ranges","bytes"},
     {"Last-Modified","Fri, 17 Dec 2004 08:38:21 GMT"},
     {"Etag","\"aa7c9dc313e4c41:d77\""},
     {"Content-Length","953"}],
    "<html>\r\n\r\n<head>\r\n<title>Messenger</title>\r\n<meta name=\"GENERATOR\" content=\"Microsoft FrontPage 5.0\">\r\n<meta name=\"ProgId\" content=\"FrontPage.Editor.Document\">\r\n<meta name=\"description\" content=\"Messenger Home Page\">\r\n</head>\r\n\r\n<frameset border=\"0\" frameborder=\"0\" rows=\"60,*\">\r\n  <frame src=\"/messenger/images/topnav.html\" name=\"mFrameTopNav\" scrolling=\"NO\" target=\"mFrameMain\">\r\n  <frameset cols=\"18%,*\">\r\n    <frameset rows=\"*,120\">\r\n      <frame src=\"index-toc.html\" name=\"mFrameTOC\" target=\"mFrameMain\" scrolling=\"auto\"  noresize=\"true\">\r\n      <frame src=\"/shared/search/namesearch.html\" name=\"mFrameNameSearch\" scrolling=\"NO\" target=\"mFrameMain\">\r\n    </frameset>\r\n    <frame src=\"home/16-12-04-xmascardsmms.htm\" name=\"mFrameMain\" scrolling=\"auto\" target=\"mFrameMain\" id=\"mFrameMain\">\r\n  </frameset>\r\n  <noframes>\r\n  <body>\r\n\r\n  <p><i>This site requires a browser that can view frames.</i></p>\r\n\r\n  </body>\r\n  </noframes>\r\n</frameset>\r\n\r\n</html>"}

%% =============================================================================
%% A GET using a proxy
7> ibrowse:send_req("http://www.google.com/", [], get, [], 
                 [{proxy_user, "XXXXX"},
                  {proxy_password, "XXXXX"},
                  {proxy_host, "proxy"},
                  {proxy_port, 8080}], 1000).
{ok,"302",
    [{"Date","Fri, 17 Dec 2004 15:22:56 GMT"},
     {"Content-Length","217"},
     {"Content-Type","text/html"},
     {"Set-Cookie",
      "PREF=ID=f58155c797f96096:CR=1:TM=1103296999:LM=1103296999:S=FiWdtAqQvhQ0TvHq; expires=Sun, 17-Jan-2038 19:14:07 GMT; path=/; domain=.google.com"},
     {"Server","GWS/2.1"},
     {"Location",
      "http://www.google.co.uk/cxfer?c=PREF%3D:TM%3D1103296999:S%3Do8bEY2FIHwdyGenS&prev=/"},
     {"Via","1.1 netapp01 (NetCache NetApp/5.5R2)"}],
    "<HTML><HEAD><TITLE>302 Moved</TITLE></HEAD><BODY>\n<H1>302 Moved</H1>\nThe document has moved\n<A HREF=\"http://www.google.co.uk/cxfer?c=PREF%3D:TM%3D1103296999:S%3Do8bEY2FIHwdyGenS&amp;prev=/\">here</A>.\r\n</BODY></HTML>\r\n"}

%% =============================================================================
%% A GET response saved to file. A temporary file is created and the
%% filename returned. The response will only be saved to file is the
%% status code is in the 200 range. The directory to download to can
%% be set using the application env var 'download_dir' - the default
%% is the current working directory.
8> ibrowse:send_req("http://www.erlang.se/", [], get, [],
                 [{proxy_user, "XXXXX"},
                  {proxy_password, "XXXXX"},
                  {proxy_host, "proxy"},
                  {proxy_port, 8080},
                  {save_response_to_file, true}], 1000).
{error,req_timedout}

%% =============================================================================
9> ibrowse:send_req("http://www.erlang.se/", [], get, [],
                 [{proxy_user, "XXXXX"},
                  {proxy_password, "XXXXX"},
                  {proxy_host, "proxy"},
                  {proxy_port, 8080},
                  {save_response_to_file, true}], 5000).
{ok,"200",
    [{"Transfer-Encoding","chunked"},
     {"Date","Fri, 17 Dec 2004 15:24:36 GMT"},
     {"Content-Type","text/html"},
     {"Server","Apache/1.3.9 (Unix)"},
     {"Via","1.1 netapp01 (NetCache NetApp/5.5R2)"}],
    {file,"/Users/chandru/code/ibrowse/src/ibrowse_tmp_file_1103297041125854"}}

%% =============================================================================
%% Setting size of connection pool and pipeline size. This sets the
%% number of maximum connections to this server to 10 and the pipeline
%% size to 1. Connections are setup a required.
11> ibrowse:set_dest("www.hotmail.com", 80, [{max_sessions, 10},
                                             {max_pipeline_size, 1}]).
ok

%% =============================================================================
%% Example using the HEAD method
56> ibrowse:send_req("http://www.erlang.org", [], head).
{ok,"200",
    [{"Date","Mon, 28 Feb 2005 04:40:53 GMT"},
     {"Server","Apache/1.3.9 (Unix)"},
     {"Last-Modified","Thu, 10 Feb 2005 09:31:23 GMT"},
     {"Etag","\"8d71d-1efa-420b29eb\""},
     {"Accept-ranges","bytes"},
     {"Content-Length","7930"},
     {"Content-Type","text/html"}],
    []}

%% =============================================================================
%% Example using the OPTIONS method
62> ibrowse:send_req("http://www.sun.com", [], options).   
{ok,"200",
    [{"Server","Sun Java System Web Server 6.1"},
     {"Date","Mon, 28 Feb 2005 04:44:39 GMT"},
     {"Content-Length","0"},
     {"P3p",
      "policyref=\"http://www.sun.com/p3p/Sun_P3P_Policy.xml\", CP=\"CAO DSP COR CUR ADMa DEVa TAIa PSAa PSDa CONi TELi OUR  SAMi PUBi IND PHY ONL PUR COM NAV INT DEM CNT STA POL PRE GOV\""},
     {"Set-Cookie",
      "SUN_ID=X.X.X.X:169191109565879; EXPIRES=Wednesday, 31-Dec-2025 23:59:59 GMT; DOMAIN=.sun.com; PATH=/"},
     {"Allow",
      "HEAD, GET, PUT, POST, DELETE, TRACE, OPTIONS, MOVE, INDEX, MKDIR, RMDIR"}],
    []}

%% =============================================================================
%% Example of using Asynchronous requests
18> ibrowse:send_req("http://www.google.com", [], get, [], 
                     [{proxy_user, "XXXXX"}, 
                      {proxy_password, "XXXXX"}, 
                      {proxy_host, "proxy"}, 
                      {proxy_port, 8080}, 
                      {stream_to, self()}]).
{ibrowse_req_id,{1115,327256,389608}}
19> flush().
Shell got {ibrowse_async_headers,{1115,327256,389608},
           "302",
           [{"Date","Thu, 05 May 2005 21:06:41 GMT"},
            {"Content-Length","217"},
            {"Content-Type","text/html"},
            {"Set-Cookie",
             "PREF=ID=b601f16bfa32f071:CR=1:TM=1115327201:LM=1115327201:S=OX5hSB525AMjUUu7; expires=Sun, 17-Jan-2038 19:14:07 GMT; path=/; domain=.google.com"},
            {"Server","GWS/2.1"},
            {"Location",
             "http://www.google.co.uk/cxfer?c=PREF%3D:TM%3D1115327201:S%3DDS9pDJ4IHcAuZ_AS&prev=/"},
            {"Via",
             "1.1 hatproxy01 (NetCache NetApp/5.6.2)"}]}
Shell got {ibrowse_async_response,{1115,327256,389608},
           "<HTML><HEAD><TITLE>302 Moved</TITLE></HEAD><BODY>\n<H1>302 Moved</H1>\nThe document has moved\n<A HREF=\"http://www.google.co.uk/cxfer?c=PREF%3D:TM%3D1115327201:S%3DDS9pDJ4IHcAuZ_AS&amp;prev=/\">here</A>.\r\n</BODY></HTML>\r\n"}
Shell got {ibrowse_async_response_end,{1115,327256,389608}}
ok

%% =============================================================================
%% Another example of using async requests
24> ibrowse:send_req("http://yaws.hyber.org/simple_ex2.yaws", [], get, [], 
                     [{proxy_user, "XXXXX"}, 
                      {proxy_password, "XXXXX"}, 
                      {proxy_host, "proxy"}, 
                      {proxy_port, 8080}, 
                      {stream_to, self()}]).
{ibrowse_req_id,{1115,327430,512314}}
25> flush().
Shell got {ibrowse_async_headers,{1115,327430,512314},
           "200", 
           [{"Date","Thu, 05 May 2005 20:58:08 GMT"},
            {"Content-Length","64"},
            {"Content-Type","text/html;charset="},
            {"Server",
             "Yaws/1.54 Yet Another Web Server"},
            {"Via",
             "1.1 hatproxy01 (NetCache NetApp/5.6.2)"}]}
Shell got {ibrowse_async_response,{1115,327430,512314},
           "<html>\n\n\n<h1> Yesssssss </h1>\n\n<h2> Hello again </h2>\n\n\n</html>\n"}
Shell got {ibrowse_async_response_end,{1115,327430,512314}}

%% =============================================================================
%% Example of request which fails when using the async option. Here
%% the {ibrowse_req_id, ReqId} is not returned. Instead the error code is
%% returned.  
68> ibrowse:send_req("http://www.earlyriser.org", [], get, [], [{stream_to, self()}]).
{error,conn_failed}

%% Example of request using both Proxy-Authorization and authorization by the final webserver.
17> ibrowse:send_req("http://www.erlang.se/lic_area/protected/patches/erl_756_otp_beam.README", 
                     [], get, [], 
                     [{proxy_user, "XXXXX"}, 
                      {proxy_password, "XXXXX"}, 
                      {proxy_host, "proxy"}, 
                      {proxy_port, 8080}, 
                      {basic_auth, {"XXXXX", "XXXXXX"}}]).
{ok,"200",
    [{"Accept-Ranges","bytes"},
     {"Date","Thu, 05 May 2005 21:02:09 GMT"},
     {"Content-Length","2088"},
     {"Content-Type","text/plain"},
     {"Server","Apache/1.3.9 (Unix)"},
     {"Last-Modified","Tue, 03 May 2005 15:08:18 GMT"},
     {"ETag","\"1384c8-828-427793e2\""},
     {"Via","1.1 hatproxy01 (NetCache NetApp/5.6.2)"}],
    "Patch Id:\t\terl_756_otp_beam\nLabel:\t\t\tinets patch\nDate:\t\t\t2005-05-03\nTrouble Report Id:\tOTP-5513, OTP-5514, OTP-5516, OTP-5517, OTP-5521, OTP-5537\nSeq num:\t\tseq9806\nSystem:\t\t\totp\nRelease:\t\tR10B\nOperating System:\tall\nArchitecture:\t\tall\nErlang machine:\t\tBEAM\nApplication:\t\tinets-4.4\nFiles:\t\t\tall\n\nDescription:\n\n    OTP-5513  The server did not handle HTTP-0.9 messages with an implicit\n\t      version.\n\n    OTP-5514  An internal server timeout killed the request handling\n\t      process without sending a message back to the client. As this\n\t      timeout only affects a single request it has been set to\n\t      infinity (if the main server process dies the request\n\t      handling process will also die and the client will receive an\n\t      error). This might make a client that does not use a timeout\n\t      hang for a longer period of time, but that is an expected\n\t      behavior!\n\n    OTP-5516  That a third party closes the http servers accept socket is\n\t      recoverable for inets, hence intes will only produce an info\n\t      report as there was no error in inets but measures where\n\t      taken to avoid failure due to errors elsewhere.\n\n    OTP-5517  The HTTP client proxy settings where ignored. Bug introduced\n\t      in inets-4.3.\n\n    OTP-5521  Inets only sent the \"WWW-Authenticate\" header at the first\n\t      attempt to get a page, if the user supplied the wrong\n\t      user/password combination the header was not sent again. This\n\t      forces the user to kill the browser entirely after a failed\n\t      login attempt, before the user may try to login again. Inets\n\t      now always send the authentication header.\n\n    OTP-5537  A major rewrite of big parts of the HTTP server code was\n\t      performed. There where many things that did not work\n\t      satisfactory. Cgi script handling can never have worked\n\t      properly and the cases when it did sort of work, a big\n\t      unnecessary delay was enforced. Headers where not always\n\t      treated as expected and HTTP version handling did not work,\n\t      all responses where sent as version HTTP/1.1 no matter what.\n\n\n"}

%% =============================================================================
%% Example of a TRACE request. Very interesting! yaws.hyber.org didn't
%% support this. Nor did www.google.com. But good old BBC supports
%% this.
35> 37> ibrowse:send_req("http://www.bbc.co.uk/", [], trace, [], 
                         [{proxy_user, "XXXXX"},
                          {proxy_password, "XXXXX"},
                          {proxy_host, "proxy"},
                          {proxy_port, 8080}]).         
{ok,"200",
    [{"Transfer-Encoding","chunked"},
     {"Date","Thu, 05 May 2005 21:40:27 GMT"},
     {"Content-Type","message/http"},
     {"Server","Apache/2.0.51 (Unix)"},
     {"Set-Cookie",
      "BBC-UID=7452e72a29424c5b0b232c7131c7d9395d209b7170e8604072e0fcb3630467300; expires=Mon, 04-May-09 21:40:27 GMT; path=/; domain=bbc.co.uk;"},
     {"Set-Cookie",
      "BBC-UID=7452e72a29424c5b0b232c7131c7d9395d209b7170e8604072e0fcb3630467300; expires=Mon, 04-May-09 21:40:27 GMT; path=/; domain=bbc.co.uk;"},
     {"Via","1.1 hatproxy01 (NetCache NetApp/5.6.2)"}],
    "TRACE / HTTP/1.1\r\nHost: www.bbc.co.uk\r\nConnection: keep-alive\r\nX-Forwarded-For: 172.24.28.29\r\nVia: 1.1 hatproxy01 (NetCache NetApp/5.6.2)\r\nCookie: BBC-UID=7452e72a29424c5b0b232c7131c7d9395d209b7170e8604072e0fcb3630467300\r\n\r\n"}