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+Updated: October 6, 2010 (http://curl.haxx.se/docs/faq.html)
+                                  _   _ ____  _
+                              ___| | | |  _ \| |
+                             / __| | | | |_) | |
+                            | (__| |_| |  _ <| |___
+                             \___|\___/|_| \_\_____|
+
+FAQ
+
+ 1. Philosophy
+  1.1 What is cURL?
+  1.2 What is libcurl?
+  1.3 What is curl not?
+  1.4 When will you make curl do XXXX ?
+  1.5 Who makes curl?
+  1.6 What do you get for making curl?
+  1.7 What about CURL from curl.com?
+  1.8 I have a problem who do I mail?
+  1.9 Where do I buy commercial support for curl?
+  1.10 How many are using curl?
+  1.11 Why don't you update ca-bundle.crt
+  1.12 I have a problem who can I chat with?
+  1.13 curl's ECCN number?
+  1.14 How do I submit my patch?
+
+ 2. Install Related Problems
+  2.1 configure doesn't find OpenSSL even when it is installed
+   2.1.1 native linker doesn't find OpenSSL
+   2.1.2 only the libssl lib is missing
+  2.2 Does curl work/build with other SSL libraries?
+  2.3 Where can I find a copy of LIBEAY32.DLL?
+  2.4 Does curl support SOCKS (RFC 1928) ?
+
+ 3. Usage Problems
+  3.1 curl: (1) SSL is disabled, https: not supported
+  3.2 How do I tell curl to resume a transfer?
+  3.3 Why doesn't my posting using -F work?
+  3.4 How do I tell curl to run custom FTP commands?
+  3.5 How can I disable the Pragma: nocache header?
+  3.6 Does curl support ASP, XML, XHTML or HTML version Y?
+  3.7 Can I use curl to delete/rename a file through FTP?
+  3.8 How do I tell curl to follow HTTP redirects?
+  3.9 How do I use curl in my favorite programming language?
+  3.10 What about SOAP, WebDAV, XML-RPC or similar protocols over HTTP?
+  3.11 How do I POST with a different Content-Type?
+  3.12 Why do FTP specific features over HTTP proxy fail?
+  3.13 Why does my single/double quotes fail?
+  3.14 Does curl support Javascript or PAC (automated proxy config)?
+  3.15 Can I do recursive fetches with curl?
+  3.16 What certificates do I need when I use SSL?
+  3.17 How do I list the root dir of an FTP server?
+  3.18 Can I use curl to send a POST/PUT and not wait for a response?
+  3.19 How do I get HTTP from a host using a specific IP address?
+
+ 4. Running Problems
+  4.1 Problems connecting to SSL servers.
+  4.2 Why do I get problems when I use & or % in the URL?
+  4.3 How can I use {, }, [ or ] to specify multiple URLs?
+  4.4 Why do I get downloaded data even though the web page doesn't exist?
+  4.5 Why do I get return code XXX from a HTTP server?
+   4.5.1 "400 Bad Request"
+   4.5.2 "401 Unauthorized"
+   4.5.3 "403 Forbidden"
+   4.5.4 "404 Not Found"
+   4.5.5 "405 Method Not Allowed"
+   4.5.6 "301 Moved Permanently"
+  4.6 Can you tell me what error code 142 means?
+  4.7 How do I keep user names and passwords secret in Curl command lines?
+  4.8 I found a bug!
+  4.9 Curl can't authenticate to the server that requires NTLM?
+  4.10 My HTTP request using HEAD, PUT or DELETE doesn't work!
+  4.11 Why does my HTTP range requests return the full document?
+  4.12 Why do I get "certificate verify failed" ?
+  4.13 Why is curl -R on Windows one hour off?
+  4.14 Redirects work in browser but not with curl!
+  4.15 FTPS doesn't work
+  4.16 My HTTP POST or PUT requests are slow!
+  4.17 Non-functional connect timeouts on Windows
+  4.18 file:// URLs containing drive letters (Windows, NetWare)
+  4.19 Why doesn't cURL return an error when the network cable is unplugged?
+
+ 5. libcurl Issues
+  5.1 Is libcurl thread-safe?
+  5.2 How can I receive all data into a large memory chunk?
+  5.3 How do I fetch multiple files with libcurl?
+  5.4 Does libcurl do Winsock initing on win32 systems?
+  5.5 Does CURLOPT_WRITEDATA and CURLOPT_READDATA work on win32 ?
+  5.6 What about Keep-Alive or persistent connections?
+  5.7 Link errors when building libcurl on Windows!
+  5.8 libcurl.so.X: open failed: No such file or directory
+  5.9 How does libcurl resolve host names?
+  5.10 How do I prevent libcurl from writing the response to stdout?
+  5.11 How do I make libcurl not receive the whole HTTP response?
+  5.12 Can I make libcurl fake or hide my real IP address?
+  5.13 How do I stop an ongoing transfer?
+  5.14 Using C++ non-static functions for callbacks?
+  5.15 How do I get an FTP directory listing?
+
+ 6. License Issues
+  6.1 I have a GPL program, can I use the libcurl library?
+  6.2 I have a closed-source program, can I use the libcurl library?
+  6.3 I have a BSD licensed program, can I use the libcurl library?
+  6.4 I have a program that uses LGPL libraries, can I use libcurl?
+  6.5 Can I modify curl/libcurl for my program and keep the changes secret?
+  6.6 Can you please change the curl/libcurl license to XXXX?
+  6.7 What are my obligations when using libcurl in my commercial apps?
+
+ 7. PHP/CURL Issues
+  7.1 What is PHP/CURL?
+  7.2 Who write PHP/CURL?
+  7.3 Can I perform multiple requests using the same handle?
+
+==============================================================================
+
+1. Philosophy
+
+  1.1 What is cURL?
+
+  cURL is the name of the project. The name is a play on 'Client for URLs',
+  originally with URL spelled in uppercase to make it obvious it deals with
+  URLs. The fact it can also be pronounced 'see URL' also helped, it works as
+  an abbreviation for "Client URL Request Library" or why not the recursive
+  version: "Curl URL Request Library".
+
+  The cURL project produces two products:
+
+  libcurl
+
+    A free and easy-to-use client-side URL transfer library, supporting DICT,
+    FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3,
+    POP3S, RTMP, RTSP, SCP, SFTP, SMTP, SMTPS, TELNET and TFTP.
+
+    libcurl supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading,
+    kerberos, HTTP form based upload, proxies, cookies, user+password
+    authentication, file transfer resume, http proxy tunneling and more!
+
+    libcurl is highly portable, it builds and works identically on numerous
+    platforms, including Solaris, NetBSD, FreeBSD, OpenBSD, Darwin, HPUX,
+    IRIX, AIX, Tru64, Linux, UnixWare, HURD, Windows, Amiga, OS/2, BeOs, Mac
+    OS X, Ultrix, QNX, OpenVMS, RISC OS, Novell NetWare, DOS, Symbian, OSF,
+    Android, Minix, IBM TPF and more...
+
+    libcurl is free, thread-safe, IPv6 compatible, feature rich, well
+    supported and fast.
+
+  curl
+
+    A command line tool for getting or sending files using URL syntax.
+
+    Since curl uses libcurl, curl supports the same wide range of common
+    Internet protocols that libcurl does.
+
+  We pronounce curl and cURL with an initial k sound: [kurl].
+
+  There are numerous sub-projects and related projects that also use the word
+  curl in the project names in various combinations, but you should take
+  notice that this FAQ is directed at the command-line tool named curl (and
+  libcurl the library), and may therefore not be valid for other curl-related
+  projects. (There is however a small section for the PHP/CURL in this FAQ.)
+
+  1.2 What is libcurl?
+
+  libcurl is a reliable and portable library which provides you with an easy
+  interface to a range of common Internet protocols.
+
+  You can use libcurl for free in your application, be it open source,
+  commercial or closed-source.
+
+  libcurl is most probably the most portable, most powerful and most often
+  used C-based multi-platform file transfer library on this planet - be it
+  open source or commercial.
+
+  1.3 What is curl not?
+
+  Curl is not a wget clone. That is a common misconception.  Never, during
+  curl's development, have we intended curl to replace wget or compete on its
+  market. Curl is targeted at single-shot file transfers.
+
+  Curl is not a web site mirroring program. If you want to use curl to mirror
+  something: fine, go ahead and write a script that wraps around curl to make
+  it reality (like curlmirror.pl does).
+
+  Curl is not an FTP site mirroring program. Sure, get and send FTP with curl
+  but if you want systematic and sequential behavior you should write a
+  script (or write a new program that interfaces libcurl) and do it.
+
+  Curl is not a PHP tool, even though it works perfectly well when used from
+  or with PHP (when using the PHP/CURL module).
+
+  Curl is not a program for a single operating system. Curl exists, compiles,
+  builds and runs under a wide range of operating systems, including all
+  modern Unixes (and a bunch of older ones too), Windows, Amiga, BeOS, OS/2,
+  OS X, QNX etc.
+
+  1.4 When will you make curl do XXXX ?
+
+  We love suggestions of what to change in order to make curl and libcurl
+  better. We do however believe in a few rules when it comes to the future of
+  curl:
+
+  * Curl -- the command line tool -- is to remain a non-graphical command line
+    tool. If you want GUIs or fancy scripting capabilities, you should look
+    for another tool that uses libcurl.
+
+  * We do not add things to curl that other small and available tools already
+    do very fine at the side. Curl's output is fine to pipe into another
+    program or redirect to another file for the next program to interpret.
+
+  * We focus on protocol related issues and improvements. If you wanna do more
+    magic with the supported protocols than curl currently does, chances are
+    big we will agree. If you wanna add more protocols, we may very well
+    agree.
+
+  * If you want someone else to make all the work while you wait for us to
+    implement it for you, that is not a very friendly attitude. We spend a
+    considerable time already on maintaining and developing curl. In order to
+    get more out of us, you should consider trading in some of your time and
+    efforts in return.
+
+  * If you write the code, chances are bigger that it will get into curl
+    faster.
+
+  1.5 Who makes curl?
+
+  curl and libcurl are not made by any single individual. Daniel Stenberg is
+  project leader and main developer, but other persons' submissions are
+  important and crucial. Anyone can contribute and post their changes and
+  improvements and have them inserted in the main sources (of course on the
+  condition that developers agree on that the fixes are good).
+
+  The full list of all contributors is found in the docs/THANKS file.
+
+  curl is developed by a community, with Daniel at the wheel.
+
+  1.6 What do you get for making curl?
+
+  Project cURL is entirely free and open. No person gets paid for developing
+  (lib)curl on full or even part time. We do this voluntarily on our spare
+  time. Occasionally companies pay individual developers to work on curl, but
+  that's up to each company and developer. It is not controlled by nor
+  supervised in any way by the project.
+
+  We still get help from companies. Haxx provides web site, bandwidth, mailing
+  lists etc and sourceforge.net hosts project services we take advantage from,
+  like the bug tracker. Also again, some companies have sponsored certain
+  parts of the development in the past and I hope some will continue to do so
+  in the future.
+
+  If you want to support our project, consider a donation or a banner-program
+  or even better: by helping us coding, documenting, testing etc.
+
+  1.7 What about CURL from curl.com?
+
+  During the summer 2001, curl.com was busy advertising their client-side
+  programming language for the web, named CURL.
+
+  We are in no way associated with curl.com or their CURL programming
+  language.
+
+  Our project name curl has been in effective use since 1998. We were not the
+  first computer related project to use the name "curl" and do not claim any
+  first-hand rights to the name.
+
+  We recognize that we will be living in parallel with curl.com and wish them
+  every success.
+
+  1.8 I have a problem who do I mail?
+
+  Please do not mail any single individual unless you really need to. Keep
+  curl-related questions on a suitable mailing list. All available mailing
+  lists are listed in the MANUAL document and online at
+  http://curl.haxx.se/mail/
+
+  Keeping curl-related questions and discussions on mailing lists allows
+  others to join in and help, to share their ideas, contribute their
+  suggestions and spread their wisdom. Keeping discussions on public mailing
+  lists also allows for others to learn from this (both current and future
+  users thanks to the web based archives of the mailing lists), thus saving us
+  from having to repeat ourselves even more. Thanks for respecting this.
+
+  If you have found or simply suspect a security problem in curl or libcurl,
+  mail curl-security at haxx.se (closed list of receivers, mails are not
+  disclosed) and tell. Then we can produce a fix in a timely manner before the
+  flaw is announced to the world, thus lessen the impact the problem will have
+  on existing users.
+
+  1.9 Where do I buy commercial support for curl?
+
+  curl is fully open source. It means you can hire any skilled engineer to fix
+  your curl-related problems.
+
+  We list available alternatives on the curl web site:
+  http://curl.haxx.se/support.html
+
+  1.10 How many are using curl?
+
+  It is impossible to tell.
+
+  We don't know how many users that knowingly have installed and use curl.
+
+  We don't know how many users that use curl without knowing that they are in
+  fact using it.
+
+  We don't know how many users that downloaded or installed curl and then
+  never use it.
+
+  Some facts to use as input to the math:
+
+  curl packages are downloaded from the curl.haxx.se and mirrors over a
+  million times per year. curl is installed by default with most Linux
+  distributions. curl is installed by default with Mac OS X. curl and libcurl
+  as used by numerous applications that include libcurl binaries in their
+  distribution packages (like Adobe Acrobat Reader and Google Earth).
+
+  More than a hundred known named companies use curl in commercial
+  environments and products and more than a hundred known named open source
+  projects depend on (lib)curl.
+
+  In a poll on the curl web site mid-2005, more than 50% of the 300+ answers
+  estimated a user base of one million users or more.
+
+  In March 2005, the "Linux Counter project" estimated a total Linux user base
+  of some 29 millions, while Netcraft detected some 4 million "active" Linux
+  based web servers. A guess is that a fair amount of these Linux
+  installations have curl installed.
+
+  The Debian project maintains statistics on packages installed by people
+  who have voluntarily run their package counting application.  In mid-2010,
+  libcurl3 was installed on over 55000 such systems (62% of reporting systems)
+  and was one of the 320 most popular installed packages (out of about 107000
+  possible packages).
+
+  All this taken together, there is no doubt that there are millions of
+  (lib)curl users.
+
+  http://curl.haxx.se/docs/companies.html
+  http://curl.haxx.se/docs/programs.html
+  http://curl.haxx.se/libcurl/using/apps.html
+  http://counter.li.org/estimates.php
+  http://news.netcraft.com/archives/2005/03/14/fedora_makes_rapid_progress.html
+  http://qa.debian.org/popcon.php?package=curl
+
+  1.11 Why don't you update ca-bundle.crt
+
+  The ca-bundle.crt file that used to be bundled with curl was very outdated
+  (it being last modified year 2000 should tell) and must be replaced with a
+  much more modern and up-to-date version by anyone who wants to verify peers
+  anyway. It is no longer provided, the last curl release that shipped it was
+  curl 7.18.0.
+
+  In the cURL project we've decided not to attempt to keep this file updated
+  (or even present anymore) since deciding what to add to a ca cert bundle is
+  an undertaking we've not been ready to accept, and the one we can get from
+  Mozilla is perfectly fine so there's no need to duplicate that work.
+
+  Today, with many services performed over HTTPS, every operating system
+  should come with a default ca cert bundle that can be deemed somewhat
+  trustworthy and that collection (if reasonably updated) should be deemed to
+  be a lot better than a private curl version.
+
+  If you want the most recent collection of ca certs that Mozilla Firefox
+  uses, we recommend that you extract the collection yourself from Mozilla
+  Firefox (by running 'make ca-bundle), or by using our online service setup
+  for this purpose: http://curl.haxx.se/docs/caextract.html
+
+  1.12 I have a problem who can I chat with?
+
+  There's a bunch of friendly people hanging out in the #curl channel on the
+  IRC network irc.freenode.net. If you're polite and nice, chances are big
+  that you can get -- or provide -- help instantly.
+
+  1.13 curl's ECCN number?
+
+  The US government restricts exports of software that contains or uses
+  cryptography. When doing so, the Export Control Classification Number (ECCN)
+  is used to identify the level of export control etc.
+
+  ASF gives a good explanation at http://www.apache.org/dev/crypto.html
+
+  We believe curl's number might be ECCN 5D002, another possibility is
+  5D992. It seems necessary to write them, asking to confirm.
+
+  Comprehensible explanations of the meaning of such numbers and how to
+  obtain them (resp.) are here
+
+  http://www.bis.doc.gov/licensing/exportingbasics.htm
+  http://www.bis.doc.gov/licensing/do_i_needaneccn.html
+
+  An incomprehensible description of the two numbers above is here
+  http://www.access.gpo.gov/bis/ear/pdf/ccl5-pt2.pdf
+
+  1.14 How do I submit my patch?
+
+  When you have made a patch or a change of whatever sort, and want to submit
+  that to the project, there are a few different ways we prefer:
+
+  o send a patch to the curl-library mailing list. We're many subscribers
+    there and there are lots of people who can review patches, comment on them
+    and "receive" them properly.
+
+  o if your patch changes or fixes a bug, you can also opt to submit a bug
+    report in the bug tracker and attach your patch there. There are less
+    people involved there.
+
+  Lots of more details are found in the CONTRIBUTE and INTERNALS docs.
+
+
+2. Install Related Problems
+
+  2.1 configure doesn't find OpenSSL even when it is installed
+
+  This may be because of several reasons.
+
+    2.1.1 native linker doesn't find openssl
+
+    Affected platforms:
+      Solaris (native cc compiler)
+      HPUX (native cc compiler)
+      SGI IRIX (native cc compiler)
+      SCO UNIX (native cc compiler)
+
+    When configuring curl, I specify --with-ssl. OpenSSL is installed in
+    /usr/local/ssl Configure reports SSL in /usr/local/ssl, but fails to find
+    CRYPTO_lock in -lcrypto
+
+    Cause: The cc for this test places the -L/usr/local/ssl/lib AFTER
+    -lcrypto, so ld can't find the library. This is due to a bug in the GNU
+    autoconf tool.
+
+    Workaround: Specifying "LDFLAGS=-L/usr/local/ssl/lib" in front of
+    ./configure places the -L/usr/local/ssl/lib early enough in the command
+    line to make things work
+
+    2.1.2 only the libssl lib is missing
+
+    If all include files and the libcrypto lib is present, with only the
+    libssl being missing according to configure, this is mostly likely because
+    a few functions are left out from the libssl.
+
+    If the function names missing include RSA or RSAREF you can be certain
+    that this is because libssl requires the RSA and RSAREF libs to build.
+
+    See the INSTALL file section that explains how to add those libs to
+    configure. Make sure that you remove the config.cache file before you
+    rerun configure with the new flags.
+
+  2.2 Does curl work/build with other SSL libraries?
+
+  Curl has been written to use OpenSSL, GnuTLS, yassl, NSS or PolarSSL,
+  although there should not be many problems using a different library. If
+  anyone does "port" curl to use a different SSL library, we are of course
+  very interested in getting the patch!
+
+  2.3 Where can I find a copy of LIBEAY32.DLL?
+
+  That is an OpenSSL binary built for Windows.
+
+  Curl uses OpenSSL to do the SSL stuff. The LIBEAY32.DLL is what curl needs
+  on a windows machine to do https://. Check out the curl web site to find
+  accurate and up-to-date pointers to recent OpenSSL DLLs and other binary
+  packages.
+
+  2.4 Does curl support SOCKS (RFC 1928) ?
+
+  Yes, SOCKS 4 and 5 are supported.
+
+
+3. Usage problems
+
+  3.1 curl: (1) SSL is disabled, https: not supported
+
+  If you get this output when trying to get anything from a https:// server,
+  it means that the configure script couldn't find all libs and include files
+  it requires for SSL to work. If the configure script fails to find them,
+  curl is simply built without SSL support.
+
+  To get the https:// support into a curl that was previously built but that
+  reports that https:// is not supported, you should dig through the document
+  and logs and check out why the configure script doesn't find the SSL libs
+  and/or include files.
+
+  Also, check out the other paragraph in this FAQ labelled "configure doesn't
+  find OpenSSL even when it is installed".
+
+  3.2 How do I tell curl to resume a transfer?
+
+  Curl supports resumed transfers both ways on both FTP and HTTP.
+
+  Try the -C option.
+
+  3.3 Why doesn't my posting using -F work?
+
+  You can't simply use -F or -d at your choice. The web server that will
+  receive your post assumes one of the formats. If the form you're trying to
+  "fake" sets the type to 'multipart/form-data', then and only then you must
+  use the -F type. In all the most common cases, you should use -d which then
+  causes a posting with the type 'application/x-www-form-urlencoded'.
+
+  This is described in some detail in the MANUAL and TheArtOfHttpScripting
+  documents, and if you don't understand it the first time, read it again
+  before you post questions about this to the mailing list. Also, try reading
+  through the mailing list archives for old postings and questions regarding
+  this.
+
+  3.4 How do I tell curl to run custom FTP commands?
+
+  You can tell curl to perform optional commands both before and/or after a
+  file transfer. Study the -Q/--quote option.
+
+  Since curl is used for file transfers, you don't use curl to just perform
+  FTP commands without transferring anything. Therefore you must always specify
+  a URL to transfer to/from even when doing custom FTP commands.
+
+  3.5 How can I disable the Pragma: nocache header?
+
+  You can change all internally generated headers by adding a replacement with
+  the -H/--header option. By adding a header with empty contents you safely
+  disable that one. Use -H "Pragma:" to disable that specific header.
+
+  3.6 Does curl support ASP, XML, XHTML or HTML version Y?
+
+  To curl, all contents are alike. It doesn't matter how the page was
+  generated. It may be ASP, PHP, Perl, shell-script, SSI or plain
+  HTML-files. There's no difference to curl and it doesn't even know what kind
+  of language that generated the page.
+
+  See also item 3.14 regarding javascript.
+
+  3.7 Can I use curl to delete/rename a file through FTP?
+
+  Yes. You specify custom FTP commands with -Q/--quote.
+
+  One example would be to delete a file after you have downloaded it:
+
+     curl -O ftp://download.com/coolfile -Q '-DELE coolfile'
+
+  or rename a file after upload:
+
+     curl -T infile ftp://upload.com/dir/ -Q "-RNFR infile" -Q "-RNTO newname"
+
+  3.8 How do I tell curl to follow HTTP redirects?
+
+  Curl does not follow so-called redirects by default. The Location: header
+  that informs the client about this is only interpreted if you're using the
+  -L/--location option. As in:
+
+     curl -L http://redirector.com
+
+  Not all redirects are HTTP ones, see 4.14
+
+  3.9 How do I use curl in my favorite programming language?
+
+  There exist many language interfaces/bindings for curl that integrates it
+  better with various languages. If you are fluid in a script language, you
+  may very well opt to use such an interface instead of using the command line
+  tool.
+
+  Find out more about which languages that support curl directly, and how to
+  install and use them, in the libcurl section of the curl web site:
+  http://curl.haxx.se/libcurl/
+
+  In October 2009, there were interfaces available for the following
+  languages: Ada95, Basic, C, C++, Ch, Cocoa, D, Dylan, Eiffel, Euphoria,
+  Ferite, Gambas, glib/GTK+, Haskell, ILE/RPG, Java, Lisp, Lua, Mono, .NET,
+  Object-Pascal, O'Caml, Pascal, Perl, PHP, PostgreSQL, Python, R, Rexx, Ruby,
+  Scheme, S-Lang, Smalltalk, SP-Forth, SPL, Tcl, Visual Basic, Visual FoxPro,
+  Q, wxwidgets and XBLite. By the time you read this, additional ones may have
+  appeared!
+
+  3.10 What about SOAP, WebDAV, XML-RPC or similar protocols over HTTP?
+
+  Curl adheres to the HTTP spec, which basically means you can play with *any*
+  protocol that is built on top of HTTP. Protocols such as SOAP, WEBDAV and
+  XML-RPC are all such ones. You can use -X to set custom requests and -H to
+  set custom headers (or replace internally generated ones).
+
+  Using libcurl is of course just as fine and you'd just use the proper
+  library options to do the same.
+
+  3.11 How do I POST with a different Content-Type?
+
+  You can always replace the internally generated headers with -H/--header.
+  To make a simple HTTP POST with text/xml as content-type, do something like:
+
+        curl -d "datatopost" -H "Content-Type: text/xml" [URL]
+
+  3.12 Why do FTP specific features over HTTP proxy fail?
+
+  Because when you use a HTTP proxy, the protocol spoken on the network will
+  be HTTP, even if you specify a FTP URL. This effectively means that you
+  normally can't use FTP specific features such as FTP upload and FTP quote
+  etc.
+
+  There is one exception to this rule, and that is if you can "tunnel through"
+  the given HTTP proxy. Proxy tunneling is enabled with a special option (-p)
+  and is generally not available as proxy admins usually disable tunneling to
+  other ports than 443 (which is used for HTTPS access through proxies).
+
+  3.13 Why does my single/double quotes fail?
+
+  To specify a command line option that includes spaces, you might need to
+  put the entire option within quotes. Like in:
+
+   curl -d " with spaces " url.com
+
+  or perhaps
+
+   curl -d ' with spaces ' url.com
+
+  Exactly what kind of quotes and how to do this is entirely up to the shell
+  or command line interpreter that you are using. For most unix shells, you
+  can more or less pick either single (') or double (") quotes. For
+  Windows/DOS prompts I believe you're forced to use double (") quotes.
+
+  Please study the documentation for your particular environment. Examples in
+  the curl docs will use a mix of both these ones as shown above. You must
+  adjust them to work in your environment.
+
+  Remember that curl works and runs on more operating systems than most single
+  individuals have ever tried.
+
+  3.14 Does curl support Javascript or PAC (automated proxy config)?
+
+  Many web pages do magic stuff using embedded Javascript. Curl and libcurl
+  have no built-in support for that, so it will be treated just like any other
+  contents.
+
+  .pac files are a netscape invention and are sometimes used by organizations
+  to allow them to differentiate which proxies to use. The .pac contents is
+  just a Javascript program that gets invoked by the browser and that returns
+  the name of the proxy to connect to. Since curl doesn't support Javascript,
+  it can't support .pac proxy configuration either.
+
+  Some workarounds usually suggested to overcome this Javascript dependency:
+
+  - Depending on the Javascript complexity, write up a script that
+    translates it to another language and execute that.
+
+  - Read the Javascript code and rewrite the same logic in another language.
+
+  - Implement a Javascript interpreter, people have successfully used the
+    Mozilla Javascript engine in the past.
+
+  - Ask your admins to stop this, for a static proxy setup or similar.
+
+  3.15 Can I do recursive fetches with curl?
+
+  No. curl itself has no code that performs recursive operations, such as
+  those performed by wget and similar tools.
+
+  There exist wrapper scripts with that functionality (for example the
+  curlmirror perl script), and you can write programs based on libcurl to do
+  it, but the command line tool curl itself cannot.
+
+  3.16 What certificates do I need when I use SSL?
+
+  There are three different kinds of "certificates" to keep track of when we
+  talk about using SSL-based protocols (HTTPS or FTPS) using curl or libcurl.
+
+  - Client certificate. The server you communicate may require that you can
+    provide this in order to prove that you actually are who you claim to be.
+    If the server doesn't require this, you don't need a client certificate.
+
+    A client certificate is always used together with a private key, and the
+    private key has a pass phrase that protects it.
+
+  - Server certificate. The server you communicate with has a server
+    certificate. You can and should verify this certificate to make sure that
+    you are truly talking to the real server and not a server impersonating
+    it.
+
+  - Certificate Authority certificate ("CA cert"). You often have several CA
+    certs in a CA cert bundle that can be used to verify a server certificate
+    that was signed by one of the authorities in the bundle. curl does not
+    come with a CA cert bundle but most curl installs provide one. You can
+    also override the default.
+
+    The server certificate verification process is made by using a Certificate
+    Authority certificate ("CA cert") that was used to sign the server
+    certificate. Server certificate verification is enabled by default in curl
+    and libcurl and is often the reason for problems as explained in FAQ entry
+    4.12 and the SSLCERTS document
+    (http://curl.haxx.se/docs/sslcerts.html). Server certificates that are
+    "self-signed" or otherwise signed by a CA that you do not have a CA cert
+    for, cannot be verified. If the verification during a connect fails, you
+    are refused access. You then need to explicitly disable the verification
+    to connect to the server.
+
+  3.17 How do I list the root dir of an FTP server?
+
+  There are two ways. The way defined in the RFC is to use an encoded slash
+  in the first path part. List the "/tmp" dir like this:
+
+     curl ftp://ftp.sunet.se/%2ftmp/
+
+  or the not-quite-kosher-but-more-readable way, by simply starting the path
+  section of the URL with a slash:
+
+     curl ftp://ftp.sunet.se//tmp/
+
+  3.18 Can I use curl to send a POST/PUT and not wait for a response?
+
+  No.
+
+  But you could easily write your own program using libcurl to do such stunts.
+
+  3.19 How do I get HTTP from a host using a specific IP address?
+
+  For example, you may be trying out a web site installation that isn't yet in
+  the DNS. Or you have a site using multiple IP addresses for a given host
+  name and you want to address a specific one out of the set.
+
+  Set a custom Host: header that identifies the server name you want to reach
+  but use the target IP address in the URL:
+
+    curl --header "Host: www.example.com" http://127.0.0.1/
+
+
+4. Running Problems
+
+  4.1 Problems connecting to SSL servers.
+
+  It took a very long time before we could sort out why curl had problems to
+  connect to certain SSL servers when using SSLeay or OpenSSL v0.9+.  The
+  error sometimes showed up similar to:
+
+  16570:error:1407D071:SSL routines:SSL2_READ:bad mac decode:s2_pkt.c:233:
+
+  It turned out to be because many older SSL servers don't deal with SSLv3
+  requests properly. To correct this problem, tell curl to select SSLv2 from
+  the command line (-2/--sslv2).
+
+  There have also been examples where the remote server didn't like the SSLv2
+  request and instead you had to force curl to use SSLv3 with -3/--sslv3.
+
+  4.2 Why do I get problems when I use & or % in the URL?
+
+  In general unix shells, the & symbol is treated specially and when used, it
+  runs the specified command in the background. To safely send the & as a part
+  of a URL, you should quote the entire URL by using single (') or double (")
+  quotes around it. Similar problems can also occur on some shells with other
+  characters, including ?*!$~(){}<>\|;`.  When in doubt, quote the URL.
+
+  An example that would invoke a remote CGI that uses &-symbols could be:
+
+     curl 'http://www.altavista.com/cgi-bin/query?text=yes&q=curl'
+
+  In Windows, the standard DOS shell treats the %-symbol specially and you
+  need to use TWO %-symbols for each single one you want to use in the URL.
+
+  Also note that if you want the literal %-symbol to be part of the data you
+  pass in a POST using -d/--data you must encode it as '%25' (which then also
+  needs the %-symbol doubled on Windows machines).
+
+  4.3 How can I use {, }, [ or ] to specify multiple URLs?
+
+  Because those letters have a special meaning to the shell, and to be used in
+  a URL specified to curl you must quote them.
+
+  An example that downloads two URLs (sequentially) would do:
+
+    curl '{curl,www}.haxx.se'
+
+  To be able to use those letters as actual parts of the URL (without using
+  them for the curl URL "globbing" system), use the -g/--globoff option:
+
+    curl -g 'www.site.com/weirdname[].html'
+
+  4.4 Why do I get downloaded data even though the web page doesn't exist?
+
+  Curl asks remote servers for the page you specify. If the page doesn't exist
+  at the server, the HTTP protocol defines how the server should respond and
+  that means that headers and a "page" will be returned. That's simply how
+  HTTP works.
+
+  By using the --fail option you can tell curl explicitly to not get any data
+  if the HTTP return code doesn't say success.
+
+  4.5 Why do I get return code XXX from a HTTP server?
+
+  RFC2616 clearly explains the return codes. This is a short transcript. Go
+  read the RFC for exact details:
+
+    4.5.1 "400 Bad Request"
+
+    The request could not be understood by the server due to malformed
+    syntax. The client SHOULD NOT repeat the request without modifications.
+
+    4.5.2 "401 Unauthorized"
+
+    The request requires user authentication.
+
+    4.5.3 "403 Forbidden"
+
+    The server understood the request, but is refusing to fulfill it.
+    Authorization will not help and the request SHOULD NOT be repeated.
+
+    4.5.4 "404 Not Found"
+
+    The server has not found anything matching the Request-URI. No indication
+    is given of whether the condition is temporary or permanent.
+
+    4.5.5 "405 Method Not Allowed"
+
+    The method specified in the Request-Line is not allowed for the resource
+    identified by the Request-URI. The response MUST include an Allow header
+    containing a list of valid methods for the requested resource.
+
+    4.5.6 "301 Moved Permanently"
+
+    If you get this return code and an HTML output similar to this:
+
+       <H1>Moved Permanently</H1> The document has moved <A
+       HREF="http://same_url_now_with_a_trailing_slash/">here</A>.
+
+    it might be because you request a directory URL but without the trailing
+    slash. Try the same operation again _with_ the trailing URL, or use the
+    -L/--location option to follow the redirection.
+
+  4.6 Can you tell me what error code 142 means?
+
+  All curl error codes are described at the end of the man page, in the
+  section called "EXIT CODES".
+
+  Error codes that are larger than the highest documented error code means
+  that curl has exited due to a crash. This is a serious error, and we
+  appreciate a detailed bug report from you that describes how we could go
+  ahead and repeat this!
+
+  4.7 How do I keep user names and passwords secret in Curl command lines?
+
+  This problem has two sides:
+
+  The first part is to avoid having clear-text passwords in the command line
+  so that they don't appear in 'ps' outputs and similar. That is easily
+  avoided by using the "-K" option to tell curl to read parameters from a file
+  or stdin to which you can pass the secret info. curl itself will also
+  attempt to "hide" the given password by blanking out the option - this
+  doesn't work on all platforms.
+
+  To keep the passwords in your account secret from the rest of the world is
+  not a task that curl addresses. You could of course encrypt them somehow to
+  at least hide them from being read by human eyes, but that is not what
+  anyone would call security.
+
+  Also note that regular HTTP (using Basic authentication) and FTP passwords
+  are sent in clear across the network. All it takes for anyone to fetch them
+  is to listen on the network.  Eavesdropping is very easy. Use more secure
+  authentication methods (like Digest, Negotiate or even NTLM) or consider the
+  SSL-based alternatives HTTPS and FTPS.
+
+  4.8 I found a bug!
+
+  It is not a bug if the behavior is documented. Read the docs first.
+  Especially check out the KNOWN_BUGS file, it may be a documented bug!
+
+  If it is a problem with a binary you've downloaded or a package for your
+  particular platform, try contacting the person who built the package/archive
+  you have.
+
+  If there is a bug, read the BUGS document first. Then report it as described
+  in there.
+
+  4.9 Curl can't authenticate to the server that requires NTLM?
+
+  NTLM support requires OpenSSL, GnuTLS, NSS or Microsoft Windows libraries at
+  build-time to provide this functionality.
+
+  NTLM is a Microsoft proprietary protocol. Proprietary formats are evil. You
+  should not use such ones.
+
+  4.10 My HTTP request using HEAD, PUT or DELETE doesn't work!
+
+  Many web servers allow or demand that the administrator configures the
+  server properly for these requests to work on the web server.
+
+  Some servers seem to support HEAD only on certain kinds of URLs.
+
+  To fully grasp this, try the documentation for the particular server
+  software you're trying to interact with. This is not anything curl can do
+  anything about.
+
+  4.11 Why does my HTTP range requests return the full document?
+
+  Because the range may not be supported by the server, or the server may
+  choose to ignore it and return the full document anyway.
+
+  4.12 Why do I get "certificate verify failed" ?
+
+  You invoke curl 7.10 or later to communicate on a https:// URL and get an
+  error back looking something similar to this:
+
+      curl: (35) SSL: error:14090086:SSL routines:
+      SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
+
+  Then it means that curl couldn't verify that the server's certificate was
+  good. Curl verifies the certificate using the CA cert bundle that comes with
+  the curl installation.
+
+  To disable the verification (which makes it act like curl did before 7.10),
+  use -k. This does however enable man-in-the-middle attacks.
+
+  If you get this failure but are having a CA cert bundle installed and used,
+  the server's certificate is not signed by one of the CA's in the bundle. It
+  might for example be self-signed. You then correct this problem by obtaining
+  a valid CA cert for the server. Or again, decrease the security by disabling
+  this check.
+
+  Details are also in the SSLCERTS file in the release archives, found online
+  here: http://curl.haxx.se/docs/sslcerts.html
+
+  4.13 Why is curl -R on Windows one hour off?
+
+  During daylight savings time, when -R is used, curl will set a time that
+  appears one hour off. This happens due to a flaw in how Windows stores and
+  uses file modification times and it is not easily worked around. For details
+  on this problem, read this: http://www.codeproject.com/datetime/dstbugs.asp
+
+  4.14 Redirects work in browser but not with curl!
+
+  curl supports HTTP redirects fine (see item 3.8). Browsers generally support
+  at least two other ways to perform directs that curl does not:
+
+  - Meta tags. You can write a HTML tag that will cause the browser to
+    redirect to another given URL after a certain time.
+
+  - Javascript. You can write a Javascript program embedded in a HTML page
+    that redirects the browser to another given URL.
+
+  There is no way to make curl follow these redirects. You must either
+  manually figure out what the page is set to do, or you write a script that
+  parses the results and fetches the new URL.
+
+  4.15 FTPS doesn't work
+
+  curl supports FTPS (sometimes known as FTP-SSL) both implicit and explicit
+  mode.
+
+  When a URL is used that starts with FTPS://, curl assumes implicit SSL on
+  the control connection and will therefore immediately connect and try to
+  speak SSL. FTPS:// connections default to port 990.
+
+  To use explicit FTPS, you use a FTP:// URL and the --ftp-ssl option (or one
+  of its related flavours). This is the most common method, and the one
+  mandated by RFC4217. This kind of connection then of course uses the
+  standard FTP port 21 by default.
+
+  4.16 My HTTP POST or PUT requests are slow!
+
+  libcurl makes all POST and PUT requests (except for POST requests with a
+  very tiny request body) use the "Expect: 100-continue" header. This header
+  allows the server to deny the operation early so that libcurl can bail out
+  already before having to send any data. This is useful in authentication
+  cases and others.
+
+  However, many servers don't implement the Expect: stuff properly and if the
+  server doesn't respond (positively) within 1 second libcurl will continue
+  and send off the data anyway.
+
+  You can disable libcurl's use of the Expect: header the same way you disable
+  any header, using -H / CURLOPT_HTTPHEADER, or by forcing it to use HTTP 1.0.
+
+  4.17 Non-functional connect timeouts
+
+  In most Windows setups having a timeout longer than 21 seconds make no
+  difference, as it will only send 3 TCP SYN packets and no more. The second
+  packet sent three seconds after the first and the third six seconds after
+  the second.  No more than three packets are sent, no matter how long the
+  timeout is set.
+
+  See option TcpMaxConnectRetransmissions on this page:
+  http://support.microsoft.com/?scid=kb%3Ben-us%3B175523&x=6&y=7
+
+  Also, even on non-Windows systems there may run a firewall or anti-virus
+  software or similar that accepts the connection but does not actually do
+  anything else. This will make (lib)curl to consider the connection connected
+  and thus the connect timeout won't trigger.
+
+  4.18 file:// URLs containing drive letters (Windows, NetWare)
+
+  When using cURL to try to download a local file, one might use a URL
+  in this format:
+
+  file://D:/blah.txt
+
+  You'll find that even if D:\blah.txt does exist, cURL returns a 'file
+  not found' error.
+
+  According to RFC 1738 (http://www.faqs.org/rfcs/rfc1738.html),
+  file:// URLs must contain a host component, but it is ignored by
+  most implementations. In the above example, 'D:' is treated as the
+  host component, and is taken away. Thus, cURL tries to open '/blah.txt'.
+  If your system is installed to drive C:, that will resolve to 'C:\blah.txt',
+  and if that doesn't exist you will get the not found error.
+
+  To fix this problem, use file:// URLs with *three* leading slashes:
+
+  file:///D:/blah.txt
+
+  Alternatively, if it makes more sense, specify 'localhost' as the host
+  component:
+
+  file://localhost/D:/blah.txt
+
+  In either case, cURL should now be looking for the correct file.
+
+  4.19 Why doesn't cURL return an error when the network cable is unplugged?
+
+  Unplugging the cable is not an error situation. The TCP/IP protocol stack
+  was designed to be fault tolerant, so even though there may be a physical
+  break somewhere the connection shouldn't be affected, just possibly
+  delayed.  Eventually, the physical break will be fixed or the data will be
+  re-routed around the physical problem.
+
+  In such cases, the TCP/IP stack is responsible for detecting when the
+  network connection is irrevocably lost. Since with some protocols it is
+  perfectly legal for the client wait indefinitely for data, the stack may
+  never report a problem, and even when it does, it can take up to 20 minutes
+  for it to detect an issue.  The curl option --keepalive-time enables
+  keep-alive support in the TCP/IP stack which makes it periodically probe the
+  connection to make sure it is still available to send data. That should
+  reliably detect any TCP/IP network failure.
+
+  But even that won't detect the network going down before the TCP/IP
+  connection is established (e.g. during a DNS lookup) or using protocols that
+  don't use TCP.  To handle those situations, curl offers a number of timeouts
+  on its own. --speed-limit/--speed-time will abort if the data transfer rate
+  falls too low, and --connect-timeout and --max-time can be used to put an
+  overall timeout on the connection phase or the entire transfer.
+
+
+5. libcurl Issues
+
+  5.1 Is libcurl thread-safe?
+
+  Yes.
+
+  We have written the libcurl code specifically adjusted for multi-threaded
+  programs. libcurl will use thread-safe functions instead of non-safe ones if
+  your system has such.
+
+  If you use a OpenSSL-powered libcurl in a multi-threaded environment, you
+  need to provide one or two locking functions:
+
+    http://www.openssl.org/docs/crypto/threads.html
+
+  If you use a GnuTLS-powered libcurl in a multi-threaded environment, you
+  need to provide locking function(s) for libgcrypt (which is used by GnuTLS
+  for the crypto functions).
+
+    http://www.gnu.org/software/gnutls/manual/html_node/Multi_002dthreaded-applications.html
+
+  No special locking is needed with a NSS-powered libcurl. NSS is thread-safe.
+
+  5.2 How can I receive all data into a large memory chunk?
+
+  [ See also the examples/getinmemory.c source ]
+
+  You are in full control of the callback function that gets called every time
+  there is data received from the remote server. You can make that callback do
+  whatever you want. You do not have to write the received data to a file.
+
+  One solution to this problem could be to have a pointer to a struct that you
+  pass to the callback function. You set the pointer using the
+  CURLOPT_WRITEDATA option. Then that pointer will be passed to the callback
+  instead of a FILE * to a file:
+
+        /* imaginary struct */
+        struct MemoryStruct {
+          char *memory;
+          size_t size;
+        };
+
+        /* imaginary callback function */
+        size_t
+        WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)
+        {
+          size_t realsize = size * nmemb;
+          struct MemoryStruct *mem = (struct MemoryStruct *)data;
+
+          mem->memory = (char *)realloc(mem->memory, mem->size + realsize + 1);
+          if (mem->memory) {
+            memcpy(&(mem->memory[mem->size]), ptr, realsize);
+            mem->size += realsize;
+            mem->memory[mem->size] = 0;
+          }
+          return realsize;
+        }
+
+  5.3 How do I fetch multiple files with libcurl?
+
+  libcurl has excellent support for transferring multiple files. You should
+  just repeatedly set new URLs with curl_easy_setopt() and then transfer it
+  with curl_easy_perform(). The handle you get from curl_easy_init() is not
+  only reusable, but you're even encouraged to reuse it if you can, as that
+  will enable libcurl to use persistent connections.
+
+  5.4 Does libcurl do Winsock initialization on win32 systems?
+
+  Yes, if told to in the curl_global_init() call.
+
+  5.5 Does CURLOPT_WRITEDATA and CURLOPT_READDATA work on win32 ?
+
+  Yes, but you cannot open a FILE * and pass the pointer to a DLL and have
+  that DLL use the FILE * (as the DLL and the client application cannot access
+  each others' variable memory areas). If you set CURLOPT_WRITEDATA you must
+  also use CURLOPT_WRITEFUNCTION as well to set a function that writes the
+  file, even if that simply writes the data to the specified FILE *.
+  Similarly, if you use CURLOPT_READDATA you must also specify
+  CURLOPT_READFUNCTION.
+
+  5.6 What about Keep-Alive or persistent connections?
+
+  curl and libcurl have excellent support for persistent connections when
+  transferring several files from the same server.  Curl will attempt to reuse
+  connections for all URLs specified on the same command line/config file, and
+  libcurl will reuse connections for all transfers that are made using the
+  same libcurl handle.
+
+  5.7 Link errors when building libcurl on Windows!
+
+  You need to make sure that your project, and all the libraries (both static
+  and dynamic) that it links against, are compiled/linked against the same run
+  time library.
+
+  This is determined by the /MD, /ML, /MT (and their corresponding /M?d)
+  options to the command line compiler. /MD (linking against MSVCRT dll) seems
+  to be the most commonly used option.
+
+  When building an application that uses the static libcurl library, you must
+  add -DCURL_STATICLIB to your CFLAGS. Otherwise the linker will look for
+  dynamic import symbols. If you're using Visual Studio, you need to instead
+  add CURL_STATICLIB in the "Preprocessor Definitions" section.
+
+  If you get linker error like "unknown symbol __imp__curl_easy_init ..." you
+  have linked against the wrong (static) library.  If you want to use the
+  libcurl.dll and import lib, you don't need any extra CFLAGS, but use one of
+  the import libraries below. These are the libraries produced by the various
+  lib/Makefile.* files:
+
+  Target:          static lib.   import lib for libcurl*.dll.
+  -----------------------------------------------------------
+  MingW:           libcurl.a     libcurldll.a
+  MSVC (release):  libcurl.lib   libcurl_imp.lib
+  MSVC (debug):    libcurld.lib  libcurld_imp.lib
+  Borland:         libcurl.lib   libcurl_imp.lib
+
+
+  5.8 libcurl.so.X: open failed: No such file or directory
+
+  This is an error message you might get when you try to run a program linked
+  with a shared version of libcurl and your run-time linker (ld.so) couldn't
+  find the shared library named libcurl.so.X. (Where X is the number of the
+  current libcurl ABI, typically 3 or 4).
+
+  You need to make sure that ld.so finds libcurl.so.X. You can do that
+  multiple ways, and it differs somewhat between different operating systems,
+  but they are usually:
+
+  * Add an option to the linker command line that specify the hard-coded path
+    the run-time linker should check for the lib (usually -R)
+
+  * Set an environment variable (LD_LIBRARY_PATH for example) where ld.so
+    should check for libs
+
+  * Adjust the system's config to check for libs in the directory where you've
+    put the dir (like Linux's /etc/ld.so.conf)
+
+  'man ld.so' and 'man ld' will tell you more details
+
+  5.9 How does libcurl resolve host names?
+
+  libcurl supports a large a number of different name resolve functions. One
+  of them is picked at build-time and will be used unconditionally. Thus, if
+  you want to change name resolver function you must rebuild libcurl and tell
+  it to use a different function.
+
+  - The non-ipv6 resolver that can use one out of four host name resolve calls
+    (depending on what your system supports):
+
+    A - gethostbyname()
+    B - gethostbyname_r() with 3 arguments
+    C - gethostbyname_r() with 5 arguments
+    D - gethostbyname_r() with 6 arguments
+
+  - The ipv6-resolver that uses getaddrinfo()
+
+  - The c-ares based name resolver that uses the c-ares library for resolves.
+    Using this offers asynchronous name resolves but it currently has no IPv6
+    support.
+
+  - The threaded resolver (default option on Windows). It uses:
+
+    A - gethostbyname() on plain ipv4 hosts
+    B - getaddrinfo() on ipv6-enabled hosts
+
+  Also note that libcurl never resolves or reverse-lookups addresses given as
+  pure numbers, such as 127.0.0.1 or ::1.
+
+  5.10 How do I prevent libcurl from writing the response to stdout?
+
+  libcurl provides a default built-in write function that writes received data
+  to stdout. Set the CURLOPT_WRITEFUNCTION to receive the data, or possibly
+  set CURLOPT_WRITEDATA to a different FILE * handle.
+
+  5.11 How do I make libcurl not receive the whole HTTP response?
+
+  You make the write callback (or progress callback) return an error and
+  libcurl will then abort the transfer.
+
+  5.12 Can I make libcurl fake or hide my real IP address?
+
+  No. libcurl operates on a higher level than so. Besides, faking IP address
+  would imply sending IP packages with a made-up source address, and then you
+  normally get a problem with intercepting the packages sent back as they
+  would then not be routed to you!
+
+  If you use a proxy to access remote sites, the sites will not see your local
+  IP address but instead the address of the proxy.
+
+  Also note that on many networks NATs or other IP-munging techniques are used
+  that makes you see and use a different IP address locally than what the
+  remote server will see you coming from.
+
+  5.13 How do I stop an ongoing transfer?
+
+  There are several ways, but none of them are instant. There is no function
+  you can call from another thread or similar that will stop it immediately.
+  Instead you need to make sure that one of the callbacks you use return an
+  appropriate value that will stop the transfer.
+
+  Suitable callbacks that you can do this with include the progress callback,
+  the read callback and the write callback.
+
+  If you're using the multi interface, you also stop a transfer by removing
+  the particular easy handle from the multi stack.
+
+  5.14 Using C++ non-static functions for callbacks?
+
+  libcurl is a C library, it doesn't know anything about C++ member functions.
+
+  You can overcome this "limitation" with a relative ease using a static
+  member function that is passed a pointer to the class:
+
+     // f is the pointer to your object.
+     static YourClass::staticFunction(void *buffer, size_t sz, size_t n, void *f)
+     {
+       // Call non-static member function.
+       static_cast<YourClass*>(f)->nonStaticFunction();
+     }
+
+     // This is how you pass pointer to the static function:
+     curl_easy_setopt(hcurl, CURLOPT_WRITEFUNCTION, YourClass:staticFunction);
+     curl_easy_setopt(hcurl, CURLOPT_WRITEDATA, this);
+
+  5.15 How do I get an FTP directory listing?
+
+  If you end the FTP URL you request with a slash, libcurl will provide you
+  with a directory listing of that given directory. You can also set
+  CURLOPT_CUSTOMREQUEST to alter what exact listing command libcurl would use
+  to list the files.
+
+  The follow-up question that tend to follow the previous one, is how a
+  program is supposed to parse the directory listing. How does it know what's
+  a file and what's a dir and what's a symlink etc. The harsh reality is that
+  FTP provides no such fine and easy-to-parse output. The output format FTP
+  servers respond to LIST commands are entirely at the server's own liking and
+  the NLST output doesn't reveal any types and in many cases don't even
+  include all the directory entries. Also, both LIST and NLST tend to hide
+  unix-style hidden files (those that start with a dot) by default so you need
+  to do "LIST -a" or similar to see them.
+
+  The application thus needs to parse the LIST output. One such existing
+  list parser is available at http://cr.yp.to/ftpparse.html  Versions of
+  libcurl since 7.21.0 also provide the ability to specify a wildcard to
+  download multiple files from one FTP directory.
+
+
+6. License Issues
+
+  Curl and libcurl are released under a MIT/X derivate license. The license is
+  very liberal and should not impose a problem for your project. This section
+  is just a brief summary for the cases we get the most questions. (Parts of
+  this section was much enhanced by Bjorn Reese.)
+
+  We are not lawyers and this is not legal advice. You should probably consult
+  one if you want true and accurate legal insights without our prejudice.
+
+  6.1 I have a GPL program, can I use the libcurl library?
+
+  Yes!
+
+  Since libcurl may be distributed under the MIT/X derivate license, it can be
+  used together with GPL in any software.
+
+  6.2 I have a closed-source program, can I use the libcurl library?
+
+  Yes!
+
+  libcurl does not put any restrictions on the program that uses the library.
+
+  6.3 I have a BSD licensed program, can I use the libcurl library?
+
+  Yes!
+
+  libcurl does not put any restrictions on the program that uses the library.
+
+  6.4 I have a program that uses LGPL libraries, can I use libcurl?
+
+  Yes!
+
+  The LGPL license doesn't clash with other licenses.
+
+  6.5 Can I modify curl/libcurl for my program and keep the changes secret?
+
+  Yes!
+
+  The MIT/X derivate license practically allows you to do almost anything with
+  the sources, on the condition that the copyright texts in the sources are
+  left intact.
+
+  6.6 Can you please change the curl/libcurl license to XXXX?
+
+  No.
+
+  We have carefully picked this license after years of development and
+  discussions and a large amount of people have contributed with source code
+  knowing that this is the license we use. This license puts the restrictions
+  we want on curl/libcurl and it does not spread to other programs or
+  libraries that use it. It should be possible for everyone to use libcurl or
+  curl in their projects, no matter what license they already have in use.
+
+  6.7 What are my obligations when using libcurl in my commercial apps?
+
+  Next to none. All you need to adhere to is the MIT-style license (stated in
+  the COPYING file) which basically says you have to include the copyright
+  notice in "all copies" and that you may not use the copyright holder's name
+  when promoting your software.
+
+  You do not have to release any of your source code.
+
+  You do not have to reveal or make public any changes to the libcurl source
+  code.
+
+  You do not have to reveal or make public that you are using libcurl within
+  your app.
+
+  As can be seen here: http://curl.haxx.se/docs/companies.html and
+  elsewhere, more and more companies are discovering the power
+  of libcurl and take advantage of it even in commercial environments.
+
+
+7. PHP/CURL Issues
+
+  7.1 What is PHP/CURL?
+
+  The module for PHP that makes it possible for PHP programs to access curl-
+  functions from within PHP.
+
+  In the cURL project we call this module PHP/CURL to differentiate it from
+  curl the command line tool and libcurl the library. The PHP team however
+  does not refer to it like this (for unknown reasons). They call it plain
+  CURL (often using all caps) or sometimes ext/curl, but both cause much
+  confusion to users which in turn gives us a higher question load.
+
+  7.2 Who write PHP/CURL?
+
+  PHP/CURL is a module that comes with the regular PHP package. It depends and
+  uses libcurl, so you need to have libcurl installed properly first before
+  PHP/CURL can be used. PHP/CURL was initially written by Sterling Hughes.
+
+  7.3 Can I perform multiple requests using the same handle?
+
+  Yes - at least in PHP version 4.3.8 and later (this has been known to not
+  work in earlier versions, but the exact version when it started to work is
+  unknown to me).
+
+  After a transfer, you just set new options in the handle and make another
+  transfer. This will make libcurl to re-use the same connection if it can.