                                  _   _ ____  _
                              ___| | | |  _ \| |
                             / __| | | | |_) | |
                            | (__| |_| |  _ <| |___
                             \___|\___/|_| \_\_____|

                                How To Compile

Installing Binary Packages
==========================

   Lots of people download binary distributions of curl and libcurl. This
   document does not describe how to install curl or libcurl using such a
   binary package. This document describes how to compile, build and install
   curl and libcurl from source code.

UNIX
====
   A normal unix installation is made in three or four steps (after you've
   unpacked the source archive):

        ./configure
        make
        make test (optional)
        make install

   You probably need to be root when doing the last command.

   If you have checked out the sources from the CVS repository, read the
   CVS-INFO on how to proceed.

   Get a full listing of all available configure options by invoking it like:

        ./configure --help

   If you want to install curl in a different file hierarchy than /usr/local,
   you need to specify that already when running configure:

        ./configure --prefix=/path/to/curl/tree

   If you happen to have write permission in that directory, you can do 'make
   install' without being root. An example of this would be to make a local
   install in your own home directory:

        ./configure --prefix=$HOME
        make
        make install

   The configure script always tries to find a working SSL library unless
   explicitly told not to. If you have OpenSSL installed in the default search
   path for your compiler/linker, you don't need to do anything special. If
   you have OpenSSL installed in /usr/local/ssl, you can run configure like:

        ./configure --with-ssl

   If you have OpenSSL installed somewhere else (for example, /opt/OpenSSL,)
   you can run configure like this:

        ./configure --with-ssl=/opt/OpenSSL

   If you insist on forcing a build without SSL support, even though you may
   have OpenSSL installed in your system, you can run configure like this:

        ./configure --without-ssl

   If you have OpenSSL installed, but with the libraries in one place and the
   header files somewhere else, you have to set the LDFLAGS and CPPFLAGS
   environment variables prior to running configure.  Something like this
   should work:

     (with the Bourne shell and its clones):

       CPPFLAGS="-I/path/to/ssl/include" LDFLAGS="-L/path/to/ssl/lib" \
           ./configure

     (with csh, tcsh and their clones):

       env CPPFLAGS="-I/path/to/ssl/include" LDFLAGS="-L/path/to/ssl/lib" \
       ./configure

   If you have shared SSL libs installed in a directory where your run-time
   linker doesn't find them (which usually causes configure failures), you can
   provide the -R option to ld on some operating systems to set a hard-coded
   path to the run-time linker:

        LDFLAGS=-R/usr/local/ssl/lib ./configure --with-ssl

   MORE OPTIONS

     To force configure to use the standard cc compiler if both cc and gcc are
     present, run configure like

       CC=cc ./configure
         or
       env CC=cc ./configure

     To force a static library compile, disable the shared library creation
     by running configure like:

       ./configure --disable-shared

     To tell the configure script to skip searching for thread-safe functions,
     add an option like:

       ./configure --disable-thread

     To build curl with kerberos4 support enabled, curl requires the krb4 libs
     and headers installed. You can then use a set of options to tell
     configure where those are:

          --with-krb4-includes[=DIR]   Specify location of kerberos4 headers
          --with-krb4-libs[=DIR]       Specify location of kerberos4 libs
          --with-krb4[=DIR]            where to look for Kerberos4

     In most cases, /usr/athena is the install prefix and then it works with

       ./configure --with-krb4=/usr/athena

     If you're a curl developer and use gcc, you might want to enable more
     debug options with the --enable-debug option.

     curl can be built to use a whole range of libraries to provide various
     useful services, and configure will try to auto-detect a decent
     default. But if you want to alter it, you can select how to deal with
     each individual library.

     To build with GnuTLS support instead of OpenSSL for SSL/TLS, note that
     you need to use both --without-ssl and --with-gnutls.

     To build with yassl support instead of OpenSSL or GunTLS, you must build
     yassl with its OpenSSL emulation enabled and point to that directory root
     with configure --with-ssl.

     To build with NSS support instead of OpenSSL for SSL/TLS, note that
     you need to use both --without-ssl and --with-nss.

     To get GSSAPI support, build with --with-gssapi and have the MIT or
     Heimdal Kerberos 5 packages installed.

     To get support for SCP and SFTP, build with --with-libssh2 and have
     libssh2 0.16 or later installed.
     

Win32
=====

   Building Windows DLLs and C run-time (CRT) linkage issues
   ---------------------------------------------------------

   As a general rule, building a DLL with static CRT linkage is highly
   discouraged, and intermixing CRTs in the same app is something to
   avoid at any cost.

   Reading and comprehension of Microsoft Knowledge Base articles
   KB94248 and KB140584 is a must for any Windows developer. Especially
   important is full understanding if you are not going to follow the
   advice given above.

   KB94248  - How To Use the C Run-Time
              http://support.microsoft.com/kb/94248/en-us

   KB140584 - How to link with the correct C Run-Time (CRT) library
              http://support.microsoft.com/kb/140584/en-us

   If your app is misbehaving in some strange way, or it is suffering
   from memory corruption, before asking for further help, please try
   first to rebuild every single library your app uses as well as your
   app using the debug multithreaded dynamic C runtime.

   MingW32
   -------

   Make sure that MinGW32's bin dir is in the search path, for example:

     set PATH=c:\mingw32\bin;%PATH%

   then run 'mingw32-make mingw32' in the root dir. There are other
   make targets available to build libcurl with more features, use:
   'mingw32-make mingw32-zlib' to build with Zlib support;
   'mingw32-make mingw32-ssl-zlib' to build with SSL and Zlib enabled;
   'mingw32-make mingw32-ssh2-ssl-zlib' to build with SSH2, SSL, Zlib;
   'mingw32-make mingw32-ssh2-ssl-sspi-zlib' to build with SSH2, SSL, Zlib
   and SSPI support.

   If you have any problems linking libraries or finding header files, be sure
   to verify that the provided "Makefile.m32" files use the proper paths, and
   adjust as necessary. It is also possible to override these paths with 
   environment variables, for example:

     set ZLIB_PATH=c:\zlib-1.2.3
     set OPENSSL_PATH=c:\openssl-0.9.8g
     set LIBSSH2_PATH=c:\libssh2-0.17

   ATTENTION: if you want to build with libssh2 support you have to use latest
   version 0.17 - previous versions will NOT work with 7.17.0 and later!
   Use 'mingw32-make mingw32-ssh2-ssl-zlib' to build with SSH2 and SSL enabled.

   It is now also possible to build with other LDAP SDKs than MS LDAP;
   currently it is possible to build with native Win32 OpenLDAP, or with the
   Novell CLDAP SDK. If you want to use these you need to set these vars:

     set LDAP_SDK=c:\openldap
     set USE_LDAP_OPENLDAP=1

   or for using the Novell SDK:

     set USE_LDAP_NOVELL=1

   If you want to enable LDAPS support then set LDAPS=1.

   - optional MingW32-built OpenlDAP SDK available from:
     http://www.gknw.net/mirror/openldap/
   - optional recent Novell CLDAP SDK available from:
     http://developer.novell.com/ndk/cldap.htm


   Cygwin
   ------

   Almost identical to the unix installation. Run the configure script in the
   curl root with 'sh configure'. Make sure you have the sh executable in
   /bin/ or you'll see the configure fail toward the end.

   Run 'make'

   Dev-Cpp
   -------

   See the separate INSTALL.devcpp file for details.

   MSVC from command line
   ----------------------

   Run the 'vcvars32.bat' file to get a proper environment. The
   vcvars32.bat file is part of the Microsoft development environment and
   you may find it in 'C:\Program Files\Microsoft Visual Studio\vc98\bin'
   provided that you installed Visual C/C++ 6 in the default directory.

   Then run 'nmake vc' in curl's root directory.

   If you want to compile with zlib support, you will need to build
   zlib (http://www.gzip.org/zlib/) as well. Please read the zlib
   documentation on how to compile zlib. Define the ZLIB_PATH environment
   variable to the location of zlib.h and zlib.lib, for example:

     set ZLIB_PATH=c:\zlib-1.2.3

   Then run 'nmake vc-zlib' in curl's root directory.

   If you want to compile with SSL support you need the OpenSSL package.
   Please read the OpenSSL documentation on how to compile and install
   the OpenSSL libraries.  The build process of OpenSSL generates the
   libeay32.dll and ssleay32.dll files in the out32dll subdirectory in
   the OpenSSL home directory.  OpenSSL static libraries (libeay32.lib,
   ssleay32.lib, RSAglue.lib) are created in the out32 subdirectory.

   Before running nmake define the OPENSSL_PATH environment variable with
   the root/base directory of OpenSSL, for example:

     set OPENSSL_PATH=c:\openssl-0.9.8g

   Then run 'nmake vc-ssl' or 'nmake vc-ssl-dll' in curl's root
   directory.  'nmake vc-ssl' will create a libcurl static and dynamic
   libraries in the lib subdirectory, as well as a statically linked
   version of curl.exe in the src subdirectory.  This statically linked
   version is a standalone executable not requiring any DLL at
   runtime. This make method requires that you have the static OpenSSL
   libraries available in OpenSSL's out32 subdirectory.
   'nmake vc-ssl-dll' creates the libcurl dynamic library and
   links curl.exe against libcurl and OpenSSL dynamically.
   This executable requires libcurl.dll and the OpenSSL DLLs
   at runtime.
   Run 'nmake vc-ssl-zlib' to build with both ssl and zlib support.

   Borland C++ compiler
   ---------------------

   compile openssl

   Make sure you include the paths to curl/include and openssl/inc32 in
   your bcc32.cnf file

   eg : -I"c:\Bcc55\include;c:\path_curl\include;c:\path_openssl\inc32"

   Check to make sure that all of the sources listed in lib/Makefile.b32
   are present in the /path_to_curl/lib directory. (Check the src
   directory for missing ones.)

   Make sure the environment variable "BCCDIR" is set to the install
   location for the compiler eg : c:\Borland\BCC55

   command line:
   make -f /path_to_curl/lib/Makefile-ssl.b32

   compile simplessl.c with appropriate links

   c:\curl\docs\examples\> bcc32 -L c:\path_to_curl\lib\libcurl.lib
                                 -L c:\borland\bcc55\lib\psdk\ws2_32.lib
                                 -L c:\openssl\out32\libeay32.lib
                                 -L c:\openssl\out32\ssleay32.lib
                                 simplessl.c


   MSVC IDE
   --------

   If you use VC++, Borland or similar compilers. Include all lib source
   files in a static lib "project" (all .c and .h files that is).
   (you should name it libcurl or similar)

   Make the sources in the src/ drawer be a "win32 console application"
   project. Name it curl.

   For VC++ 6, there's an included Makefile.vc6 that should be possible
   to use out-of-the-box.


   Disabling Specific Protocols in Win32 builds
   --------------------------------------------

   The configure utility, unfortunately, is not available for the Windows
   environment, therefore, you cannot use the various disable-protocol
   options of the configure utility on this platform.

   However, you can use the following defines to disable specific
   protocols:

   HTTP_ONLY             disables all protocols except HTTP
   CURL_DISABLE_FTP      disables FTP
   CURL_DISABLE_LDAP     disables LDAP
   CURL_DISABLE_TELNET   disables TELNET
   CURL_DISABLE_DICT     disables DICT
   CURL_DISABLE_FILE     disables FILE
   CURL_DISABLE_TFTP     disables TFTP

   If you want to set any of these defines you have the following
   possibilities:

   - Modify lib/setup.h
   - Modify lib/Makefile.vc6
   - Add defines to Project/Settings/C/C++/General/Preprocessor Definitions
     in the curllib.dsw/curllib.dsp Visual C++ 6 IDE project.


   Important static libcurl usage note
   -----------------------------------

   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.


IBM OS/2
========
   Building under OS/2 is not much different from building under unix.
   You need:

      - emx 0.9d
      - GNU make
      - GNU patch
      - ksh
      - GNU bison
      - GNU file utilities
      - GNU sed
      - autoconf 2.13

   If you want to build with OpenSSL or OpenLDAP support, you'll need to
   download those libraries, too. Dirk Ohme has done some work to port SSL
   libraries under OS/2, but it looks like he doesn't care about emx.  You'll
   find his patches on: http://come.to/Dirk_Ohme

   If during the linking you get an error about _errno being an undefined
   symbol referenced from the text segment, you need to add -D__ST_MT_ERRNO__
   in your definitions.

   If everything seems to work fine but there's no curl.exe, you need to add
   -Zexe to your linker flags.

   If you're getting huge binaries, probably your makefiles have the -g in
   CFLAGS.


VMS
===
   (The VMS section is in whole contributed by the friendly Nico Baggus)

   Curl seems to work with FTP & HTTP other protocols are not tested.  (the
   perl http/ftp testing server supplied as testing too cannot work on VMS
   because vms has no concept of fork(). [ I tried to give it a whack, but
   thats of no use.

   SSL stuff has not been ported.

   Telnet has about the same issues as for Win32. When the changes for Win32
   are clear maybe they'll work for VMS too. The basic problem is that select
   ONLY works for sockets.

   Marked instances of fopen/[f]stat that might become a problem, especially
   for non stream files. In this regard, the files opened for writing will be
   created stream/lf and will thus be safe. Just keep in mind that non-binary
   read/wring from/to files will have a records size limit of 32767 bytes
   imposed.

   Stat to get the size of the files is again only safe for stream files &
   fixed record files without implied CC.

   -- My guess is that only allowing access to stream files is the quickest
   way to get around the most issues. Therefore all files need to to be
   checked to be sure they will be stream/lf before processing them.  This is
   the easiest way out, I know. The reason for this is that code that needs to
   report the filesize will become a pain in the ass otherwise.

   Exit status.... Well we needed something done here,

   VMS has a structured exist status:
   | 3  |       2    |     1       |  0|
   |1098|765432109876|5432109876543|210|
   +----+------------+-------------+---+
   |Ctrl|  Facility  | Error code  |sev|
   +----+------------+-------------+---+

   With the Ctrl-bits an application can tell if part or the whole message has
   already been printed from the program, DCL doesn't need to print it again.

   Facility - basically the program ID. A code assigned to the program
   the name can be fetched from external or internal message libraries
   Error code - the err codes assigned by the application
   Sev. - severity: Even = error, off = non error
      0 = Warning
      1 = Success
      2 = Error
      3 = Information
      4 = Fatal
      <5-7> reserved.

   This all presents itself with:
   %<FACILITY>-<Sev>-<Errorname>, <Error message>

   See also the src/curlmsg.msg file, it has the source for the messages In
   src/main.c a section is devoted to message status values, the globalvalues
   create symbols with certain values, referenced from a compiled message
   file. Have all exit function use a exit status derived from a translation
   table with the compiled message codes.

   This was all compiled with:

      Compaq C V6.2-003 on OpenVMS Alpha V7.1-1H2

   So far for porting notes as of:
   13-jul-2001
   N. Baggus


QNX
===
   (This section was graciously brought to us by David Bentham)

   As QNX is targeted for resource constrained environments, the QNX headers
   set conservative limits. This includes the FD_SETSIZE macro, set by default
   to 32. Socket descriptors returned within the CURL library may exceed this,
   resulting in memory faults/SIGSEGV crashes when passed into select(..)
   calls using fd_set macros.

   A good all-round solution to this is to override the default when building
   libcurl, by overriding CFLAGS during configure, example
   #  configure CFLAGS='-DFD_SETSIZE=64 -g -O2'


RISC OS
=======
   The library can be cross-compiled using gccsdk as follows:

        CC=riscos-gcc AR=riscos-ar RANLIB='riscos-ar -s' ./configure \
             --host=arm-riscos-aof --without-random --disable-shared
        make

   where riscos-gcc and riscos-ar are links to the gccsdk tools.
   You can then link your program with curl/lib/.libs/libcurl.a


AmigaOS
=======
   (This section was graciously brought to us by Diego Casorran)

   To build cURL/libcurl on AmigaOS just type 'make amiga' ...

   What you need is:    (not tested with others versions)

        GeekGadgets / gcc 2.95.3 (http://www.geekgadgets.org/)

        AmiTCP SDK v4.3 (http://www.aminet.net/comm/tcp/AmiTCP-SDK-4.3.lha)

        Native Developer Kit (http://www.amiga.com/3.9/download/NDK3.9.lha)

   As no ixemul.library is required you will be able to build it for
   WarpOS/PowerPC (not tested by me), as well a MorphOS version should be
   possible with no problems.

   To enable SSL support, you need a OpenSSL native version (without ixemul),
   you can find a precompiled package at http://amiga.sourceforge.net/OpenSSL/


NetWare
=======
   To compile curl.nlm / libcurl.nlm you need:
   - either any gcc / nlmconv, or CodeWarrior 7 PDK 4 or later.
   - gnu make and awk running on the platform you compile on;
     native Win32 versions can be downloaded from:
     http://www.gknw.net/development/prgtools/
   - recent Novell LibC SDK available from:
     http://developer.novell.com/ndk/libc.htm
   - or recent Novell CLib SDK available from:
     http://developer.novell.com/ndk/clib.htm
   - optional recent Novell CLDAP SDK available from:
     http://developer.novell.com/ndk/cldap.htm
   - optional zlib sources (static or dynamic linking with zlib.imp);
     sources with NetWare Makefile can be obtained from:
     http://www.gknw.net/mirror/zlib/
   - optional OpenSSL sources (version 0.9.8 or later build with BSD sockets);
     you can find precompiled packages at:
     http://www.gknw.net/development/ossl/netware/
     for CLIB-based builds OpenSSL needs to be patched to build with BSD
     sockets (currently only a winsock-based CLIB build is supported):
     http://www.gknw.net/development/ossl/netware/patches/v_0.9.8g/openssl-0.9.8g.diff
   - optional SSH2 sources (version 0.17 or later);

   Set a search path to your compiler, linker and tools; on Linux make
   sure that the var OSTYPE contains the string 'linux'; set the var
   NDKBASE to point to the base of your Novell NDK; and then type
   'make netware' from the top source directory; other targets available
   are 'netware-ssl', 'netware-ssl-zlib', 'netware-zlib' and 'netware-ares';
   if you need other combinations you can control the build with the
   environment variables WITH_SSL, WITH_ZLIB, WITH_ARES, WITH_SSH2, and
   ENABLE_IPV6; you can set LINK_STATIC=1 to link curl.nlm statically.
   By default LDAP support is enabled, however currently you will need a patch
   in order to use the CLDAP NDK with BSD sockets (Novell Bug 300237):
   http://www.gknw.net/test/curl/cldap_ndk/ldap_ndk.diff
   I found on some Linux systems (RH9) that OS detection didn't work although
   a 'set | grep OSTYPE' shows the var present and set; I simply overwrote it
   with 'OSTYPE=linux-rh9-gnu' and the detection in the Makefile worked...
   Any help in testing appreciated!
   Builds automatically created 8 times a day from current CVS are here:
   http://www.gknw.net/mirror/curl/autobuilds/
   the status of these builds can be viewed at the autobuild table:
   http://curl.haxx.se/auto/


eCos
====
   curl does not use the eCos build system, so you must first build eCos
   separately, then link curl to the resulting eCos library.  Here's a sample
   configure line to do so on an x86 Linux box targeting x86:

   GCCLIB=`gcc -print-libgcc-file-name` && \
   CFLAGS="-D__ECOS=1 -nostdinc -I$ECOS_INSTALL/include \
    -I`dirname $GCCLIB`/include" \
   LDFLAGS="-nostdlib -Wl,--gc-sections -Wl,-static \
    -L$ECOS_INSTALL/lib -Ttarget.ld -ltarget" \
   ./configure --host=i386 --disable-shared \
    --without-ssl --without-zlib --disable-manual --disable-ldap

   In most cases, eCos users will be using libcurl from within a custom
   embedded application.  Using the standard 'curl' executable from
   within eCos means facing the limitation of the standard eCos C
   startup code which does not allow passing arguments in main().  To
   run 'curl' from eCos and have it do something useful, you will need
   to either modify the eCos startup code to pass in some arguments, or
   modify the curl application itself to retrieve its arguments from
   some location set by the bootloader or hard-code them.

   Something like the following patch could be used to hard-code some
   arguments.  The MTAB_ENTRY line mounts a RAM disk as the root filesystem
   (without mounting some kind of filesystem, eCos errors out all file
   operations which curl does not take to well).  The next section synthesizes
   some command-line arguments for curl to use, in this case to direct curl
   to read further arguments from a file.  It then creates that file on the
   RAM disk and places within it a URL to download: a file: URL that
   just happens to point to the configuration file itself.  The results
   of running curl in this way is the contents of the configuration file
   printed to the console.

--- src/main.c	19 Jul 2006 19:09:56 -0000	1.363
+++ src/main.c	24 Jul 2006 21:37:23 -0000
@@ -4286,11 +4286,31 @@
 }
 
 
+#ifdef __ECOS
+#include <cyg/fileio/fileio.h>
+MTAB_ENTRY( testfs_mte1,
+                   "/",
+                   "ramfs",
+                   "",
+                   0);
+#endif
 
 int main(int argc, char *argv[])
 {
   int res;
   struct Configurable config;
+#ifdef __ECOS
+  char *args[] = {"ecos-curl", "-K", "curlconf.txt"};
+  FILE *f;
+  argc = sizeof(args)/sizeof(args[0]);
+  argv = args;
+
+  f = fopen("curlconf.txt", "w");
+  if (f) {
+    fprintf(f, "--url file:curlconf.txt");
+    fclose(f);
+  }
+#endif
   memset(&config, 0, sizeof(struct Configurable));
 
   config.errors = stderr; /* default errors to stderr */


Minix
=====
   curl can be compiled on Minix 3 using gcc or ACK (starting with
   ver. 3.1.3).  The default heap size allocated to several required
   programs is inadequate for configuring and compiling curl and will
   result in strange errors unless fixed (which only needs to be done
   once).
   
   ACK
   ---
   Increase heap sizes with the commands:

     chmem =1024000 /usr/lib/em_cemcom.ansi
     chmem =512000 /usr/lib/i386/as

   If you have bash installed:

     chmem =2048000 /usr/local/bin/bash

   Configure and compile with:

     ./configure CC=cc LD=cc GREP=grep CPPFLAGS=-D_POSIX_SOURCE=1
     make

   GCC
   ---
   If you have bash installed:

     chmem =2048000 /usr/local/bin/bash

   Make sure gcc is in your PATH with the command:
   
     export PATH=/usr/gnu/bin:$PATH
   
   then configure and compile curl with:

     ./configure CC=gcc GREP=grep AR=/usr/gnu/bin/gar
     make


Symbian OS
==========
   The Symbian OS port uses the Symbian build system to compile.  From the
   packages/Symbian/group/ directory, run:

      bldmake bldfiles
      abld build

   to compile and install curl and libcurl. If your Symbian SDK doesn't
   include support for P.I.P.S., you will need to contact your SDK vendor
   to obtain that first.


CROSS COMPILE
=============
   (This section was graciously brought to us by Jim Duey, with additions by
   Dan Fandrich)

   Download and unpack the cURL package.  Version should be 7.9.1 or later.

   'cd' to the new directory. (e.g. cd curl-7.12.3)

   Set environment variables to point to the cross-compile toolchain and call
   configure with any options you need.  Be sure and specify the '--host' and
   '--build' parameters at configuration time.  The following script is an
   example of cross-compiling for the IBM 405GP PowerPC processor using the
   toolchain from MonteVista for Hardhat Linux.

   (begin script)

   #! /bin/sh

   export PATH=$PATH:/opt/hardhat/devkit/ppc/405/bin
   export CPPFLAGS="-I/opt/hardhat/devkit/ppc/405/target/usr/include"
   export AR=ppc_405-ar
   export AS=ppc_405-as
   export LD=ppc_405-ld
   export RANLIB=ppc_405-ranlib
   export CC=ppc_405-gcc
   export NM=ppc_405-nm

   ./configure --target=powerpc-hardhat-linux \
	--host=powerpc-hardhat-linux \
	--build=i586-pc-linux-gnu \
	--prefix=/opt/hardhat/devkit/ppc/405/target/usr/local \
	--exec-prefix=/usr/local

   (end script)

   You may also need to provide a parameter like '--with-random=/dev/urandom'
   to configure as it cannot detect the presence of a random number
   generating device for a target system.  The '--prefix' parameter
   specifies where cURL will be installed.  If 'configure' completes
   successfully, do 'make' and 'make install' as usual.

   In some cases, you may be able to simplify the above commands to as
   little as:

       ./configure --host=ARCH-OS


REDUCING SIZE
=============
   There are a number of configure options that can be used to reduce the
   size of libcurl for embedded applications where binary size is an
   important factor.  First, be sure to set the CFLAGS variable when
   configuring with any relevant compiler optimization flags to reduce the
   size of the binary.  For gcc, this would mean at minimum the -Os option,
   potentially the -march=X and -mdynamic-no-pic options as well, e.g.:

      ./configure CFLAGS='-Os' ...

   Note that newer compilers often produce smaller code than older versions
   due to better optimization.

   Be sure to specify as many --disable- and --without- flags on the configure
   command-line as you can to disable all the libcurl features that you
   know your application is not going to need.  Besides specifying the
   --disable-PROTOCOL flags for all the types of URLs your application
   will not use, here are some other flags that can reduce the size of the
   library:

     --disable-ares (disables support for the ARES DNS library)
     --disable-cookies (disables support for HTTP cookies)
     --disable-crypto-auth (disables HTTP cryptographic authentication)
     --disable-ipv6 (disables support for IPv6)
     --disable-verbose (eliminates debugging strings and error code strings)
     --enable-hidden-symbols (eliminates unneeded symbols in the shared library)
     --without-libidn (disables support for the libidn DNS library)
     --without-ssl (disables support for SSL/TLS)
     --without-zlib (disables support for on-the-fly decompression)

   The GNU linker has a number of options to reduce the size of the libcurl
   dynamic libraries on some platforms even further. Specify them by giving
   the options -Wl,-Bsymbolic and -Wl,-s on the gcc command-line.  
   Be sure also to strip debugging symbols from your binaries after
   compiling using 'strip' (or the appropriate variant if cross-compiling).
   If space is really tight, you may be able to remove some unneeded
   sections of the shared library using the -R option to objcopy (e.g. the
   .comment section).

   Using these techniques it is possible to create an HTTP-only shared libcurl
   library for i386 Linux platforms that is only 96 KiB in size (as of libcurl
   version 7.17.1, using gcc 4.2.2).

   You may find that statically linking libcurl to your application will
   result in a lower total size.


PORTS
=====
   This is a probably incomplete list of known hardware and operating systems
   that curl has been compiled for. If you know a system curl compiles and
   runs on, that isn't listed, please let us know!

        - Alpha DEC OSF 4
        - Alpha Digital UNIX v3.2
        - Alpha FreeBSD 4.1, 4.5
        - Alpha Linux 2.2, 2.4
        - Alpha NetBSD 1.5.2
        - Alpha OpenBSD 3.0
        - Alpha OpenVMS V7.1-1H2
        - Alpha Tru64 v5.0 5.1
        - HP-PA HP-UX 9.X 10.X 11.X
        - HP-PA Linux
        - HP3000 MPE/iX
        - MIPS IRIX 6.2, 6.5
        - MIPS Linux
        - OS/400
        - Pocket PC/Win CE 3.0
        - Power AIX 3.2.5, 4.2, 4.3.1, 4.3.2, 5.1, 5.2
        - PowerPC Darwin 1.0
        - PowerPC Linux
        - PowerPC Mac OS 9
        - PowerPC Mac OS X
        - SH4 Linux 2.6.X
        - SH4 OS21
        - SINIX-Z v5
        - Sparc Linux
        - Sparc Solaris 2.4, 2.5, 2.5.1, 2.6, 7, 8, 9, 10
        - Sparc SunOS 4.1.X
        - StrongARM (and other ARM) RISC OS 3.1, 4.02
        - StrongARM/ARM7/ARM9 Linux 2.4, 2.6
        - StrongARM NetBSD 1.4.1
        - Symbian OS (P.I.P.S.)
        - TPF
        - Ultrix 4.3a
        - UNICOS 9.0
        - i386 BeOS
        - i386 DOS
        - i386 eCos 1.3.1
        - i386 Esix 4.1
        - i386 FreeBSD
        - i386 HURD
        - i386 Haiku OS
        - i386 Linux 1.3, 2.0, 2.2, 2.3, 2.4, 2.6
        - i386 MINIX 3.1
        - i386 NetBSD
        - i386 Novell NetWare
        - i386 OS/2
        - i386 OpenBSD
        - i386 QNX 6
        - i386 SCO unix
        - i386 Solaris 2.7
        - i386 Windows 95, 98, ME, NT, 2000, XP, 2003
        - i486 ncr-sysv4.3.03 (NCR MP-RAS)
        - ia64 Linux 2.3.99
        - m68k AmigaOS 3
        - m68k Linux
        - m68k uClinux
        - m68k OpenBSD
        - m88k dg-dgux5.4R3.00
        - s390 Linux
        - XScale/PXA250 Linux 2.4
        - Nios II uClinux

Useful URLs
===========

OpenSSL   http://www.openssl.org
MingW     http://www.mingw.org
OpenLDAP  http://www.openldap.org
Zlib      http://www.gzip.org/zlib/
libssh2   http://www.libssh2.org