1 # how to install curl and libcurl
3 ## Installing Binary Packages
5 Lots of people download binary distributions of curl and libcurl. This
6 document does not describe how to install curl or libcurl using such a binary
7 package. This document describes how to compile, build and install curl and
8 libcurl from source code.
12 If you get your code off a git repository instead of a release tarball, see
13 the `GIT-INFO` file in the root directory for specific instructions on how to
18 A normal Unix installation is made in three or four steps (after you've
19 unpacked the source archive):
26 You probably need to be root when doing the last command.
28 Get a full listing of all available configure options by invoking it like:
32 If you want to install curl in a different file hierarchy than `/usr/local`,
33 specify that when running configure:
35 ./configure --prefix=/path/to/curl/tree
37 If you have write permission in that directory, you can do 'make install'
38 without being root. An example of this would be to make a local install in
39 your own home directory:
41 ./configure --prefix=$HOME
45 The configure script always tries to find a working SSL library unless
46 explicitly told not to. If you have OpenSSL installed in the default search
47 path for your compiler/linker, you don't need to do anything special. If you
48 have OpenSSL installed in /usr/local/ssl, you can run configure like:
50 ./configure --with-ssl
52 If you have OpenSSL installed somewhere else (for example, /opt/OpenSSL) and
53 you have pkg-config installed, set the pkg-config path first, like this:
55 env PKG_CONFIG_PATH=/opt/OpenSSL/lib/pkgconfig ./configure --with-ssl
57 Without pkg-config installed, use this:
59 ./configure --with-ssl=/opt/OpenSSL
61 If you insist on forcing a build without SSL support, even though you may
62 have OpenSSL installed in your system, you can run configure like this:
64 ./configure --without-ssl
66 If you have OpenSSL installed, but with the libraries in one place and the
67 header files somewhere else, you have to set the LDFLAGS and CPPFLAGS
68 environment variables prior to running configure. Something like this should
71 CPPFLAGS="-I/path/to/ssl/include" LDFLAGS="-L/path/to/ssl/lib" ./configure
73 If you have shared SSL libs installed in a directory where your run-time
74 linker doesn't find them (which usually causes configure failures), you can
75 provide the -R option to ld on some operating systems to set a hard-coded
76 path to the run-time linker:
78 LDFLAGS=-R/usr/local/ssl/lib ./configure --with-ssl
82 To force a static library compile, disable the shared library creation by
83 running configure like:
85 ./configure --disable-shared
87 To tell the configure script to skip searching for thread-safe functions, add
90 ./configure --disable-thread
92 If you're a curl developer and use gcc, you might want to enable more debug
93 options with the `--enable-debug` option.
95 curl can be built to use a whole range of libraries to provide various useful
96 services, and configure will try to auto-detect a decent default. But if you
97 want to alter it, you can select how to deal with each individual library.
101 The default OpenSSL configure check will also detect and use BoringSSL or
104 - GnuTLS: `--without-ssl --with-gnutls`.
105 - Cyassl: `--without-ssl --with-cyassl`
106 - NSS: `--without-ssl --with-nss`
107 - PolarSSL: `--without-ssl --with-polarssl`
108 - mbedTLS: `--without-ssl --with-mbedtls`
109 - axTLS: `--without-ssl --with-axtls`
110 - schannel: `--without-ssl --with-winssl`
111 - secure transport: `--without-ssl --with-darwinssl`
115 ## Building Windows DLLs and C run-time (CRT) linkage issues
117 As a general rule, building a DLL with static CRT linkage is highly
118 discouraged, and intermixing CRTs in the same app is something to avoid at
121 Reading and comprehending Microsoft Knowledge Base articles KB94248 and
122 KB140584 is a must for any Windows developer. Especially important is full
123 understanding if you are not going to follow the advice given above.
125 - [How To Use the C Run-Time](https://support.microsoft.com/kb/94248/en-us)
126 - [How to link with the correct C Run-Time CRT library](https://support.microsoft.com/kb/140584/en-us)
127 - [Potential Errors Passing CRT Objects Across DLL Boundaries](https://msdn.microsoft.com/en-us/library/ms235460)
129 If your app is misbehaving in some strange way, or it is suffering from
130 memory corruption, before asking for further help, please try first to
131 rebuild every single library your app uses as well as your app using the
132 debug multithreaded dynamic C runtime.
134 If you get linkage errors read section 5.7 of the FAQ document.
138 Make sure that MinGW32's bin dir is in the search path, for example:
140 set PATH=c:\mingw32\bin;%PATH%
142 then run `mingw32-make mingw32` in the root dir. There are other
143 make targets available to build libcurl with more features, use:
145 - `mingw32-make mingw32-zlib` to build with Zlib support;
146 - `mingw32-make mingw32-ssl-zlib` to build with SSL and Zlib enabled;
147 - `mingw32-make mingw32-ssh2-ssl-zlib` to build with SSH2, SSL, Zlib;
148 - `mingw32-make mingw32-ssh2-ssl-sspi-zlib` to build with SSH2, SSL, Zlib
151 If you have any problems linking libraries or finding header files, be sure
152 to verify that the provided "Makefile.m32" files use the proper paths, and
153 adjust as necessary. It is also possible to override these paths with
154 environment variables, for example:
156 set ZLIB_PATH=c:\zlib-1.2.8
157 set OPENSSL_PATH=c:\openssl-1.0.2c
158 set LIBSSH2_PATH=c:\libssh2-1.6.0
160 It is also possible to build with other LDAP SDKs than MS LDAP; currently
161 it is possible to build with native Win32 OpenLDAP, or with the Novell CLDAP
162 SDK. If you want to use these you need to set these vars:
164 set LDAP_SDK=c:\openldap
165 set USE_LDAP_OPENLDAP=1
167 or for using the Novell SDK:
169 set USE_LDAP_NOVELL=1
171 If you want to enable LDAPS support then set LDAPS=1.
175 Almost identical to the unix installation. Run the configure script in the
176 curl source tree root with `sh configure`. Make sure you have the sh
177 executable in /bin/ or you'll see the configure fail toward the end.
181 ## Borland C++ compiler
183 Ensure that your build environment is properly set up to use the compiler and
184 associated tools. PATH environment variable must include the path to bin
185 subdirectory of your compiler installation, eg: `c:\Borland\BCC55\bin`
187 It is advisable to set environment variable BCCDIR to the base path of the
188 compiler installation.
190 set BCCDIR=c:\Borland\BCC55
192 In order to build a plain vanilla version of curl and libcurl run the
193 following command from curl's root directory:
197 To build curl and libcurl with zlib and OpenSSL support set environment
198 variables `ZLIB_PATH` and `OPENSSL_PATH` to the base subdirectories of the
199 already built zlib and OpenSSL libraries and from curl's root directory run
202 make borland-ssl-zlib
204 libcurl library will be built in 'lib' subdirectory while curl tool is built
205 in 'src' subdirectory. In order to use libcurl library it is advisable to
206 modify compiler's configuration file bcc32.cfg located in
207 `c:\Borland\BCC55\bin` to reflect the location of libraries include paths for
208 example the '-I' line could result in something like:
210 -I"c:\Borland\BCC55\include;c:\curl\include;c:\openssl\inc32"
212 bcc3.cfg `-L` line could also be modified to reflect the location of of
213 libcurl library resulting for example:
215 -L"c:\Borland\BCC55\lib;c:\curl\lib;c:\openssl\out32"
217 In order to build sample program `simple.c` from the docs\examples
218 subdirectory run following command from mentioned subdirectory:
220 bcc32 simple.c libcurl.lib cw32mt.lib
222 In order to build sample program simplessl.c an SSL enabled libcurl is
223 required, as well as the OpenSSL libeay32.lib and ssleay32.lib libraries.
225 In order to build sample program `sslbackend.c`, an SSL enabled libcurl
228 ## Disabling Specific Protocols in Windows builds
230 The configure utility, unfortunately, is not available for the Windows
231 environment, therefore, you cannot use the various disable-protocol options of
232 the configure utility on this platform.
234 However, you can use the following defines to disable specific
237 - `HTTP_ONLY` disables all protocols except HTTP
238 - `CURL_DISABLE_FTP` disables FTP
239 - `CURL_DISABLE_LDAP` disables LDAP
240 - `CURL_DISABLE_TELNET` disables TELNET
241 - `CURL_DISABLE_DICT` disables DICT
242 - `CURL_DISABLE_FILE` disables FILE
243 - `CURL_DISABLE_TFTP` disables TFTP
244 - `CURL_DISABLE_HTTP` disables HTTP
245 - `CURL_DISABLE_IMAP` disables IMAP
246 - `CURL_DISABLE_POP3` disables POP3
247 - `CURL_DISABLE_SMTP` disables SMTP
249 If you want to set any of these defines you have the following options:
251 - Modify lib/config-win32.h
252 - Modify lib/curl_setup.h
253 - Modify winbuild/Makefile.vc
254 - Modify the "Preprocessor Definitions" in the libcurl project
256 Note: The pre-processor settings can be found using the Visual Studio IDE
257 under "Project -> Settings -> C/C++ -> General" in VC6 and "Project ->
258 Properties -> Configuration Properties -> C/C++ -> Preprocessor" in later
261 ## Using BSD-style lwIP instead of Winsock TCP/IP stack in Win32 builds
263 In order to compile libcurl and curl using BSD-style lwIP TCP/IP stack it is
264 necessary to make definition of preprocessor symbol USE_LWIPSOCK visible to
265 libcurl and curl compilation processes. To set this definition you have the
266 following alternatives:
268 - Modify lib/config-win32.h and src/config-win32.h
269 - Modify winbuild/Makefile.vc
270 - Modify the "Preprocessor Definitions" in the libcurl project
272 Note: The pre-processor settings can be found using the Visual Studio IDE
273 under "Project -> Settings -> C/C++ -> General" in VC6 and "Project ->
274 Properties -> Configuration Properties -> C/C++ -> Preprocessor" in later
277 Once that libcurl has been built with BSD-style lwIP TCP/IP stack support, in
278 order to use it with your program it is mandatory that your program includes
279 lwIP header file `<lwip/opt.h>` (or another lwIP header that includes this)
280 before including any libcurl header. Your program does not need the
281 `USE_LWIPSOCK` preprocessor definition which is for libcurl internals only.
283 Compilation has been verified with [lwIP
284 1.4.0](https://download.savannah.gnu.org/releases/lwip/lwip-1.4.0.zip) and
285 [contrib-1.4.0](https://download.savannah.gnu.org/releases/lwip/contrib-1.4.0.zip).
287 This BSD-style lwIP TCP/IP stack support must be considered experimental given
288 that it has been verified that lwIP 1.4.0 still needs some polish, and libcurl
289 might yet need some additional adjustment, caveat emptor.
291 ## Important static libcurl usage note
293 When building an application that uses the static libcurl library on Windows,
294 you must add `-DCURL_STATICLIB` to your `CFLAGS`. Otherwise the linker will
295 look for dynamic import symbols.
297 ## Legacy Windows and SSL
299 WinSSL (specifically SChannel from Windows SSPI), is the native SSL library in
300 Windows. However, WinSSL in Windows <= XP is unable to connect to servers that
301 no longer support the legacy handshakes and algorithms used by those
302 versions. If you will be using curl in one of those earlier versions of
303 Windows you should choose another SSL backend such as OpenSSL.
305 # Apple iOS and Mac OS X
307 On modern Apple operating systems, curl can be built to use Apple's SSL/TLS
308 implementation, Secure Transport, instead of OpenSSL. To build with Secure
309 Transport for SSL/TLS, use the configure option `--with-darwinssl`. (It is not
310 necessary to use the option `--without-ssl`.) This feature requires iOS 5.0 or
311 later, or OS X 10.5 ("Leopard") or later.
313 When Secure Transport is in use, the curl options `--cacert` and `--capath`
314 and their libcurl equivalents, will be ignored, because Secure Transport uses
315 the certificates stored in the Keychain to evaluate whether or not to trust
316 the server. This, of course, includes the root certificates that ship with the
317 OS. The `--cert` and `--engine` options, and their libcurl equivalents, are
318 currently unimplemented in curl with Secure Transport.
320 For OS X users: In OS X 10.8 ("Mountain Lion"), Apple made a major overhaul to
321 the Secure Transport API that, among other things, added support for the newer
322 TLS 1.1 and 1.2 protocols. To get curl to support TLS 1.1 and 1.2, you must
323 build curl on Mountain Lion or later, or by using the equivalent SDK. If you
324 set the `MACOSX_DEPLOYMENT_TARGET` environmental variable to an earlier
325 version of OS X prior to building curl, then curl will use the new Secure
326 Transport API on Mountain Lion and later, and fall back on the older API when
327 the same curl binary is executed on older cats. For example, running these
328 commands in curl's directory in the shell will build the code such that it
329 will run on cats as old as OS X 10.6 ("Snow Leopard") (using bash):
331 export MACOSX_DEPLOYMENT_TARGET="10.6"
332 ./configure --with-darwinssl
337 Download and unpack the curl package.
339 'cd' to the new directory. (e.g. `cd curl-7.12.3`)
341 Set environment variables to point to the cross-compile toolchain and call
342 configure with any options you need. Be sure and specify the `--host` and
343 `--build` parameters at configuration time. The following script is an
344 example of cross-compiling for the IBM 405GP PowerPC processor using the
345 toolchain from MonteVista for Hardhat Linux.
349 export PATH=$PATH:/opt/hardhat/devkit/ppc/405/bin
350 export CPPFLAGS="-I/opt/hardhat/devkit/ppc/405/target/usr/include"
354 export RANLIB=ppc_405-ranlib
355 export CC=ppc_405-gcc
358 ./configure --target=powerpc-hardhat-linux
359 --host=powerpc-hardhat-linux
360 --build=i586-pc-linux-gnu
361 --prefix=/opt/hardhat/devkit/ppc/405/target/usr/local
362 --exec-prefix=/usr/local
364 You may also need to provide a parameter like `--with-random=/dev/urandom` to
365 configure as it cannot detect the presence of a random number generating
366 device for a target system. The `--prefix` parameter specifies where curl
367 will be installed. If `configure` completes successfully, do `make` and `make
370 In some cases, you may be able to simplify the above commands to as little as:
372 ./configure --host=ARCH-OS
376 There are a number of configure options that can be used to reduce the size of
377 libcurl for embedded applications where binary size is an important factor.
378 First, be sure to set the CFLAGS variable when configuring with any relevant
379 compiler optimization flags to reduce the size of the binary. For gcc, this
380 would mean at minimum the -Os option, and potentially the `-march=X`,
381 `-mdynamic-no-pic` and `-flto` options as well, e.g.
383 ./configure CFLAGS='-Os' LDFLAGS='-Wl,-Bsymbolic'...
385 Note that newer compilers often produce smaller code than older versions
386 due to improved optimization.
388 Be sure to specify as many `--disable-` and `--without-` flags on the
389 configure command-line as you can to disable all the libcurl features that you
390 know your application is not going to need. Besides specifying the
391 `--disable-PROTOCOL` flags for all the types of URLs your application will not
392 use, here are some other flags that can reduce the size of the library:
394 - `--disable-ares` (disables support for the C-ARES DNS library)
395 - `--disable-cookies` (disables support for HTTP cookies)
396 - `--disable-crypto-auth` (disables HTTP cryptographic authentication)
397 - `--disable-ipv6` (disables support for IPv6)
398 - `--disable-manual` (disables support for the built-in documentation)
399 - `--disable-proxy` (disables support for HTTP and SOCKS proxies)
400 - `--disable-unix-sockets` (disables support for UNIX sockets)
401 - `--disable-verbose` (eliminates debugging strings and error code strings)
402 - `--disable-versioned-symbols` (disables support for versioned symbols)
403 - `--enable-hidden-symbols` (eliminates unneeded symbols in the shared library)
404 - `--without-libidn` (disables support for the libidn DNS library)
405 - `--without-librtmp` (disables support for RTMP)
406 - `--without-ssl` (disables support for SSL/TLS)
407 - `--without-zlib` (disables support for on-the-fly decompression)
409 The GNU compiler and linker have a number of options that can reduce the
410 size of the libcurl dynamic libraries on some platforms even further.
411 Specify them by providing appropriate CFLAGS and LDFLAGS variables on the
412 configure command-line, e.g.
414 CFLAGS="-Os -ffunction-sections -fdata-sections
415 -fno-unwind-tables -fno-asynchronous-unwind-tables -flto"
416 LDFLAGS="-Wl,-s -Wl,-Bsymbolic -Wl,--gc-sections"
418 Be sure also to strip debugging symbols from your binaries after compiling
419 using 'strip' (or the appropriate variant if cross-compiling). If space is
420 really tight, you may be able to remove some unneeded sections of the shared
421 library using the -R option to objcopy (e.g. the .comment section).
423 Using these techniques it is possible to create a basic HTTP-only shared
424 libcurl library for i386 Linux platforms that is only 113 KiB in size, and an
425 FTP-only library that is 113 KiB in size (as of libcurl version 7.50.3, using
428 You may find that statically linking libcurl to your application will result
429 in a lower total size than dynamically linking.
431 Note that the curl test harness can detect the use of some, but not all, of
432 the `--disable` statements suggested above. Use will cause tests relying on
433 those features to fail. The test harness can be manually forced to skip the
434 relevant tests by specifying certain key words on the runtests.pl command
435 line. Following is a list of appropriate key words:
437 - `--disable-cookies` !cookies
438 - `--disable-manual` !--manual
439 - `--disable-proxy` !HTTP\ proxy !proxytunnel !SOCKS4 !SOCKS5
443 This is a probably incomplete list of known hardware and operating systems
444 that curl has been compiled for. If you know a system curl compiles and
445 runs on, that isn't listed, please let us know!
448 - Alpha Digital UNIX v3.2
449 - Alpha FreeBSD 4.1, 4.5
450 - Alpha Linux 2.2, 2.4
453 - Alpha OpenVMS V7.1-1H2
454 - Alpha Tru64 v5.0 5.1
456 - ARM Android 1.5, 2.1, 2.3, 3.2, 4.x
461 - HP-PA HP-UX 9.X 10.X 11.X
468 - Pocket PC/Win CE 3.0
469 - Power AIX 3.2.5, 4.2, 4.3.1, 4.3.2, 5.1, 5.2
479 - Sparc Solaris 2.4, 2.5, 2.5.1, 2.6, 7, 8, 9, 10
481 - StrongARM (and other ARM) RISC OS 3.1, 4.02
482 - StrongARM/ARM7/ARM9 Linux 2.4, 2.6
483 - StrongARM NetBSD 1.4.1
484 - Symbian OS (P.I.P.S.) 9.x
495 - i386 Linux 1.3, 2.0, 2.2, 2.3, 2.4, 2.6
499 - i386 Novell NetWare
505 - i386 Windows 95, 98, ME, NT, 2000, XP, 2003
506 - i486 ncr-sysv4.3.03 (NCR MP-RAS)
512 - m88k dg-dgux5.4R3.00
515 - XScale/PXA250 Linux 2.4