# Installation

Overview
Building with an IDE or Makefile
Building with Boost.Build

## Overview

Most of Boost.Iostreams can be used simply by including appropriate headers. This is true, for instance, of all the core components — including `stream`, `stream_buffer`, `filtering_stream` and `filtering_streambuf` — and of about two thirds of the concrete Filters and Devices. Some components, however, are implemented in `.cpp` files; in addition, the regular expression filters depend on Boost.Regex, and the compressions filters rely on the third-party libraries zlib ([Gailly]), libbz2 ([Seward]) and liblzma ([Collin]). Note that liblzma refers to the version from xz-utils which is the version available in for example Linux distributions, not the liblzma from the LZMA SDK from 7zip. To obatin zlib and libbz2, see the instructions here and here.

The components which are implemented in `.cpp` or which rely on external libraries can be built in two ways: by adding the appropriate `.cpp` files to your IDE project or makefile, or by using Boost.Build.

## Building with an IDE or Makefile

The following table shows which headers contain components defined in `.cpp` files. If your application includes one of these headers, you'll need to add the corresponding `.cpp` files to you IDE project or makefile, and to define the preprocessor symbol `BOOST_IOSTREAMS_NO_LIB`. In addition, if the `.cpp` file depends on an external library, you'll have to build it from the source or link to a pre-built binary.

Header | Source File | External Library
--- | --- | ---
`boost/iostreams/device/file_descriptor.hpp` | `file_descriptor.cpp` | -
`boost/iostreams/device/mapped_file.hpp` | `mapped_file.cpp` | -
`boost/iostreams/filter/bzip2.hpp` | `bzip2.cpp` | libbz2
`boost/iostreams/filter/gzip.hpp` | `gzip.cpp`, `zlib.cpp` | zlib
`boost/iostreams/filter/regex.hpp` | - | Boost.Regex
`boost/iostreams/filter/zlib.hpp` | `zlib.cpp` | zlib
`boost/iostreams/filter/lzma.hpp` | `lzma.cpp` | liblzma

## Building with Boost.Build

To build with Boost.Build, run b2 from the directory `libs/iostreams/build`, or from the Boost root directory.

If you want to use the compression filters when building iostreams, you have two choices. You can setup the zlib, bzip2 and/or LZMA toolsets in Boost Build in a jamfile, preferably user-config.jam, as documented in Boost.Build. Note that building from source is not supported for LZMA. Alternatively you can let iostreams setup the zlib, bzip2 and/or LZMA toolsets for you using default values. The former is preferred, especially if your zlib and/or bzip2 installations cannot be found by the iostreams setup.

On most UNIX systems, it should not be necessary to setup the zlib, bzip2 and/or lzma toolsets since the zlib, libbz2 and liblzma headers and binaries are already installed in locations where they will be found automatically. On Windows the zlib, bzip2 and/or LZMA binaries need to be in the PATH, else they will not ordinarily be found by default, so it is always a good idea under Windows to setup the zlib, bzip2 and/or LZMA toolsets in your own jamfile.

You can turn off compression filters when building iostreams by passing one of the Boost Build variables in the table below, defined to 1, using the -s option:

Variable | Interpretation
--- | ---
`NO_COMPRESSION` | Disable support for compression filters.
`NO_BZIP2` | Disable support for the bzip2 filters.
`NO_ZLIB` | Disable support for the zlib filters.
`NO_LZMA` | Disable support for the LZMA/xz filters.

© Copyright 2008 CodeRage, LLC
© Copyright 2004-2007 Jonathan Turkanis

Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)