Getting Started on Unix VariantsIndex 1 Get BoostThe most reliable way to get a copy of Boost is to download a distribution from SourceForge:
Other Packages RedHat, Debian, and other distribution packagers supply Boost library packages, however you may need to adapt these instructions if you use third-party packages, because their creators usually choose to break Boost up into several packages, reorganize the directory structure of the Boost distribution, and/or rename the library binaries.1 If you have any trouble, we suggest using an official Boost distribution from SourceForge. 2 The Boost DistributionThis is a sketch of the resulting directory structure: boost_1_36_0/ .................The “boost root directory” index.htm .........A copy of www.boost.org starts here boost/ .........................All Boost Header files libs/ ............Tests, .cpps, docs, etc., by library index.html ........Library documentation starts here algorithm/ any/ array/ …more libraries… status/ .........................Boost-wide test suite tools/ ...........Utilities, e.g. bjam, quickbook, bcp more/ ..........................Policy documents, etc. doc/ ...............A subset of all Boost library docs It's important to note the following:
3 Header-Only LibrariesThe first thing many people want to know is, “how do I build Boost?” The good news is that often, there's nothing to build. Nothing to Build? Most Boost libraries are header-only: they consist entirely of header files containing templates and inline functions, and require no separately-compiled library binaries or special treatment when linking. The only Boost libraries that must be built separately are:
A few libraries have optional separately-compiled binaries:
4 Build a Simple Program Using BoostTo keep things simple, let's start by using a header-only library. The following program reads a sequence of integers from standard input, uses Boost.Lambda to multiply each number by three, and writes them to standard output: #include <boost/lambda/lambda.hpp> #include <iostream> #include <iterator> #include <algorithm> int main() { using namespace boost::lambda; typedef std::istream_iterator<int> in; std::for_each( in(std::cin), in(), std::cout << (_1 * 3) << " " ); } Copy the text of this program into a file called example.cpp. Now, in the directory where you saved example.cpp, issue the following command:
c++ -I path/to/boost_1_36_0 example.cpp -o example
To test the result, type: echo 1 2 3 | ./example 4.1 Errors and WarningsDon't be alarmed if you see compiler warnings originating in Boost headers. We try to eliminate them, but doing so isn't always practical.3 Errors are another matter. If you're seeing compilation errors at this point in the tutorial, check to be sure you've copied the example program correctly and that you've correctly identified the Boost root directory. 5 Prepare to Use a Boost Library BinaryIf you want to use any of the separately-compiled Boost libraries, you'll need to acquire library binaries. 5.1 Easy Build and InstallIssue the following commands in the shell (don't type $; that represents the shell's prompt):
$ cd path/to/boost_1_36_0
$ ./configure --help
Select your configuration options and invoke ./configure again without the --help option. Unless you have write permission in your system's /usr/local/ directory, you'll probably want to at least use $ ./configure --prefix=path/to/installation/prefix to install somewhere else. Also, consider using the --show-libraries and --with-libraries= options to limit the long wait you'll experience if you build everything. Finally, $ make install will leave Boost binaries in the lib/ subdirectory of your installation prefix. You will also find a copy of the Boost headers in the include/ subdirectory of the installation prefix, so you can henceforth use that directory as an #include path in place of the Boost root directory. 5.2 Or, Build Custom BinariesIf you're using a compiler other than your system's default, you'll need to use Boost.Build to create binaries. You'll also use this method if you need a nonstandard build variant (see the Boost.Build documentation for more details). Boost.Build is a text-based system for developing, testing, and installing software. To use it, you'll need an executable called bjam. 5.2.1 Get bjambjam is the command-line tool that drives the Boost Build system. To build Boost binaries, you'll invoke bjam from the Boost root. Boost provides pre-compiled bjam executables for a variety of platforms. Alternatively, you can build bjam yourself using these instructions. 5.2.2 Identify Your ToolsetFirst, find the toolset corresponding to your compiler in the following table. Note If you previously chose a toolset for the purposes of building bjam, you should assume it won't work and instead choose newly from the table below.
If you have multiple versions of a particular compiler installed, you can append the version number to the toolset name, preceded by a hyphen, e.g. intel-9.0 or borland-5.4.3. 5.2.3 Select a Build DirectoryBoost.Build will place all intermediate files it generates while building into the build directory. If your Boost root directory is writable, this step isn't strictly necessary: by default Boost.Build will create a bin.v2/ subdirectory for that purpose in your current working directory. 5.2.4 Invoke bjamChange your current directory to the Boost root directory and invoke bjam as follows: bjam --build-dir=build-directory --toolset=toolset-name [--build-type=complete] stage For example, your session might look like this:
$ cd ~/boost_1_36_0
$ bjam --build-dir=/tmp/build-boost --toolset=gcc stage
That will build static and shared non-debug multi-threaded variations of the libraries. To build all variations:
$ cd ~/boost_1_36_0
$ bjam --build-dir=/tmp/build-boost --toolset=gcc --build-type=complete stage
Building the special stage target places Boost library binaries in the stage/ subdirectory of your build directory. Note bjam is case-sensitive; it is important that all the parts shown in bold type above be entirely lower-case. For a description of other options you can pass when invoking bjam, type: bjam --help In particular, to limit the amount of time spent building, you may be interested in:
5.3 Expected Build OutputDuring the process of building Boost libraries, you can expect to see some messages printed on the console. These may include
5.4 In Case of Build ErrorsThe only error messages you see when building Boost—if any—should be related to the IOStreams library's support of zip and bzip2 formats as described here. Install the relevant development packages for libz and libbz2 if you need those features. Other errors when building Boost libraries are cause for concern. If it seems like the build system can't find your compiler and/or linker, consider setting up a user-config.jam file as described in the Boost.Build documentation. If that isn't your problem or the user-config.jam file doesn't work for you, please address questions about configuring Boost for your compiler to the Boost.Build mailing list. 6 Link Your Program to a Boost LibraryTo demonstrate linking with a Boost binary library, we'll use the following simple program that extracts the subject lines from emails. It uses the Boost.Regex library, which has a separately-compiled binary component. #include <boost/regex.hpp> #include <iostream> #include <string> int main() { std::string line; boost::regex pat( "^Subject: (Re: |Aw: )*(.*)" ); while (std::cin) { std::getline(std::cin, line); boost::smatch matches; if (boost::regex_match(line, matches, pat)) std::cout << matches[2] << std::endl; } } There are two main challenges associated with linking:
There are two main ways to link to libraries:
In both cases above, the bold text is what you'd add to the command lines we explored earlier. 6.1 Library NamingIn order to choose the right binary for your build configuration you need to know how Boost binaries are named. Each library filename is composed of a common sequence of elements that describe how it was built. For example, libboost_regex-vc71-mt-d-1_34.lib can be broken down into the following elements:
6.2 Test Your ProgramTo test our subject extraction, we'll filter the following text file. Copy it out of your browser and save it as jayne.txt: To: George Shmidlap From: Rita Marlowe Subject: Will Success Spoil Rock Hunter? --- See subject. If you linked to a shared library, you may need to prepare some platform-specific settings so that the system will be able to find and load it when your program is run. Most platforms have an environment variable to which you can add the directory containing the library. On many platforms (Linux, FreeBSD) that variable is LD_LIBRARY_PATH, but on MacOS it's DYLD_LIBRARY_PATH, and on Cygwin it's simply PATH. In most shells other than csh and tcsh, you can adjust the variable as follows (again, don't type the $—that represents the shell prompt): $ VARIABLE_NAME=path/to/lib/directory:${VARIABLE_NAME} $ export VARIABLE_NAME On csh and tcsh, it's $ setenv VARIABLE_NAME path/to/lib/directory:${VARIABLE_NAME} Once the necessary variable (if any) is set, you can run your program as follows: $ path/to/compiled/example < path/to/jayne.txt The program should respond with the email subject, “Will Success Spoil Rock Hunter?” 7 Conclusion and Further ResourcesThis concludes your introduction to Boost and to integrating it with your programs. As you start using Boost in earnest, there are surely a few additional points you'll wish we had covered. One day we may have a “Book 2 in the Getting Started series” that addresses them. Until then, we suggest you pursue the following resources. If you can't find what you need, or there's anything we can do to make this document clearer, please post it to the Boost Users' mailing list.
Onward
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