Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of boost. Click here for the latest Boost documentation.



After years of bjam developments.. This is going to be the last unbundled release of the 3.1.x series. From this point forward bjam will only be bundled as part of the larger Boost Build system. And hence will likely change name at some point. As a side effect of this move people will get more frequent release of bjam (or whatever it ends up being called).

  • New built-ins, MD5, SPLIT_BY_CHARACTERS, PRECIOUS, PAD, FILE_OPEN, and UPDATE_NOW. -- Vladimir P.
  • Ensure all file descriptors are closed when executing actions complete on *nix. -- Noel B.
  • Fix warnings, patch from Mateusz Loskot. -- Vladimir P.
  • Add KEEP_GOING var to programatically override the '-q' option. -- Vladimir P.
  • Add more parameters, up to 19 from 9, to rule invocations. Patch from Jonathan Biggar. -- Vladimir P.
  • Print failed command output even if the normally quite '-d0' option. -- Vladimir P.
  • Build of bjam with vc10, aka Visual Studio 2010. -- Vladimir P.
  • More macros for detection of OSPLAT, patch from John W. Bito. -- Vladimir P.
  • Add PARALLELISM var to programatically override the '-j' option. -- Vladimir P.
  • Tweak doc building to allow for PDF generation of docs. -- John M.


A year in the making this release has many stability improvements and various performance improvements. And because of the efforts of Jurko the code is considerably more readable!

  • Reflect the results of calling bjam from Python. -- Rene R.
  • For building on Windows: Rework how arguments are parsed and tested to fix handling of quoted arguments, options arguments, and arguments with "=". -- Rene R.
  • Try to work around at least one compiler bug with GCC and variable aliasing that causes crashes with hashing file cache entries. -- Rene R.
  • Add -Wc,-fno-strict-aliasing for QCC/QNX to avoid the same aliasing crashes as in the general GCC 4.x series (thanks to Niklas Angare for the fix). -- Rene R.
  • On Windows let the child bjam commands inherit stdin, as some commands assume it's available. -- Rene R.
  • On Windows don't limit bjam output to ASCII as some tools output characters in extended character sets. -- Rene R.
  • Isolate running of bjam tests to individual bjam instances to prevent possible spillover errors from one test affecting another test. Separate the bjam used to run the tests vs. the bjam being tested. And add automatic re-building of the bjam being tested. -- Rene R.
  • Fix some possible overrun issues revealed by Fortify build. Thanks to Steven Robbins for pointing out the issues. -- Rene R.
  • Handle \n and \r escape sequences. -- Vladimir P.
  • Minor edits to remove -Wall warnings. -- Rene R.
  • Dynamically adjust pwd buffer query size to allow for when PATH_MAX is default defined instead of being provided by the system C library. -- Rene R.
  • Minor perf improvement for bjam by replacing hash function with faster version. Only 1% diff for Boost tree. -- Rene R.
  • Updated Boost Jam's error location reporting when parsing Jamfiles. Now it reports the correct error location information when encountering an unexpected EOF. It now also reports where an invalid lexical token being read started instead of finished which makes it much easier to find errors like unclosed quotes or curly braces. -- Jurko G.
  • Removed the -xarch=generic architecture from build.jam as this option is unknown so the Sun compilers on Linux. -- Noel B.
  • Fixed a bug with T_FATE_ISTMP getting reported as T_FATE_ISTMP & T_FATE_NEEDTMP at the same time due to a missing break in a switch statement. -- Jurko G.
  • Fixed a Boost Jam bug causing it to sometimes trigger actions depending on targets that have not been built yet. -- Jurko G.
  • Added missing documentation for Boost Jam's :T variable expansion modifier which converts all back-slashes ('\') to forward slashed ('/'). -- Jurko G.
  • Added Boost Jam support for executing command lines longer than 2047 characters (up to 8191) characters when running on Windows XP or later OS version. -- Jurko G.
  • Fixed a Boost Jam bug on Windows causing its SHELL command not to work correctly with some commands containing quotes. -- Jurko G.
  • Corrected a potential memory leak in Boost Jam's builtin_shell() function that would appear should Boost Jam ever start to release its allocated string objects. -- Jurko G.
  • Made all Boost Jam's ECHO commands automatically flush the standard output to make that output more promptly displayed to the user. -- Jurko G.
  • Made Boost Jam tests quote their bjam executable name when calling it allowing those executables to contain spaces in their name and/or path. -- Jurko G.
  • Change execunix.c to always use fork() instead of vfork() on the Mac. This works around known issues with bjam on PPC under Tiger and a problem reported by Rene with bjam on x86 under Leopard. -- Noel B.
  • Corrected a bug in Boost Jam's base Jambase script causing it to trim the error message displayed when its boost-build rule gets called multiple times. -- Jurko G.
  • When importing from Python into an module with empty string as name, import into root module. -- Vladimir P.
  • Patch for the NORMALIZE_PATH builtin Boost Jam rule as well as an appropriate update for the path.jam Boost Build module where that rule was being used to implement path join and related operations. -- Jurko G.
  • Fixed a bug causing Boost Jam not to handle target file names specified as both short and long file names correctly. -- Jurko G.
  • Relaxed test, ignoring case of drive letter. -- Roland S.
  • Implemented a patch contributed by Igor Nazarenko reimplementing the list_sort() function to use a C qsort() function instead of a hand-crafted merge-sort algorithm. Makes some list sortings (e.g. 1,2,1,2,1,2,1,2, ...) extremely faster, in turn significantly speeding up some project builds. -- Jurko G.
  • Fixed a bug with bjam not handling the '' root Windows path correctly without its drive letter being specified. -- Jurko G.
  • Solved the problem with child process returning the value 259 (Windows constant STILL_ACTIVE) causing bjam never to detect that it exited and therefore keep running in an endless loop. -- Jurko G.
  • Solved the problem with bjam going into an active wait state, hogging up processor resources, when waiting for one of its child processes to terminate while not all of its available child process slots are being used. -- Jurko G.
  • Solved a race condition between bjam's output reading/child process termination detection and the child process's output generation/termination which could have caused bjam not to collect the terminated process's final output. -- Jurko G.
  • Change from vfork to fork for executing actions on Darwin to improve stability. -- Noel B.
  • Code reformatting and cleanups. -- Jurko G.
  • Implement ISFILE built-in. -- Vladimir P.


This is mostly a bug fix release.

  • Work around some Windows CMD.EXE programs that will fail executing a totally empty batch file. -- Rene R.
  • Add support for detection and building with vc9. -- John P.
  • Plug memory leak when closing out actions. Thanks to Martin Kortmann for finding this. -- Rene R.
  • Various improvements to __TIMING_RULE__ and __ACTION_RULE__ target variable hooks. -- Rene R.
  • Change JAMDATE to use common ISO date format. -- Rene R.
  • Add test for result status values of simple actions, i.e. empty actions. -- Rene R.
  • Fix buffer overrun bug in expanding @() subexpressions. -- Rene R.
  • Check empty string invariants, instead of assuming all strings are allocated. And reset strings when they are freed. -- Rene R.
  • Add OSPLAT=PARISC for HP-UX PA-RISC. -- Boris G.
  • Make quietly actions really quiet by not printing the command output. The output for the quietly actions is still available through __ACTION_RULE__. -- Rene R.
  • Switch intel-win32 to use static multi thread runtime since the single thread static runtime is no longer available. -- Rene R.
  • When setting OSPLAT, check __ia64 macro. -- Boris G.
  • Get the unix timing working correctly. -- Noel B.
  • Add -fno-strict-aliasing to compilation with gcc. Which works around GCC-4.2 crash problems. -- Boris G.
  • Increased support for Python integration. -- Vladimir P., Daniel W.
  • Allow specifying options with quotes, i.e. --with-python=xyz, to work around the CMD shell using = as an argument separator. -- Rene R.
  • Add values of variables specified with -s to .EVNRION module, so that we can override environment on command line. -- Vladimir P.
  • Make NORMALIZE_PATH convert \ to /. -- Vladimir P.


This release sees a variety of fixes for long standing Perforce/Jam problems. Most of them relating to running actions in parallel with the -jN option. The end result of the changes is that running parallel actions is now reliably possible in Unix and Windows environments. Many thanks to Noel for joining the effort, to implement and fix the Unix side of stuff.

  • Add support for building bjam with pgi and pathscale toolsets. -- Noel B.
  • Implement running action commands through pipes (-p option) to fix jumbled output when using parallel execution with -j option. This is implemented for Unix variants, and Windows (Win32/NT). -- Rene R., Noel B.
  • Add "sun" as alias to Sun Workshop compiler tools. -- Rene R.
  • Set MAXLINE in jam.h to 23k bytes for AIX. The piecemeal archive action was broken with the default MAXLINE of 102400. Because the AIX shell uses some of the 24k default buffer size for its own use, I reduced it to 23k. -- Noel B.
  • Make use of output dir options of msvc to not polute src dir with compiled files. -- Rene R.
  • A small fix, so -d+2 will always show the "real" commands being executed instead of casually the name of a temporary batch file. -- Roland S.
  • Add test to check 'bjam -n'. -- Rene R.
  • Add test to check 'bjam -d2'. -- Rene R.
  • Bring back missing output of -n option. The -o option continues to be broken as it has been for a long time now because of the @ file feature. -- Rene R.
  • Update GC support to work with Boehm GC 7.0. -- Rene R.
  • Revert the BOOST_BUILD_PATH change, since the directory passed to boost-build should be first in searched paths, else project local build system will not be picked correctly. The order had been changed to allow searching of alternate user-config.jam files from boost build. This better should be done with --user-config= switch or similar. -- Roland S.
  • Initial support for defining action body from Python. -- Vladimir P.
  • Implement @() expansion during parse phase. -- Rene R.
  • Define OSPLAT var unconditionally, and more generically, when possible. -- Rene R.
  • Fix undeclared INT_MAX on some platforms, i.e. Linux. -- Rene R.
  • Modified execunix.c to add support for terminating processes that consume too much cpu or that hang and fail to consume cpu at all. This in support of the bjam -lx option. -- Noel B.
  • Add internal dependencies for multi-file generating actions to indicate that the targets all only appear when the first target appears. This fixes the long standing problem Perforce/Jam has with multi-file actions and parallel execution (-jN). -- Rene R.
  • Add test of -l limit option now that it's implemented on windows and unix. -- Rene R.
  • Add test for no-op @() expansion. -- Rene R.
  • Handle invalid formats of @() as doing a straight substitution instead of erroring out. -- Rene R.
  • Various fixes to compile on SGI/Irix. -- Noel B.
  • Add output for when actions timeout with -lN option. -- Rene R., Noel B.
  • Add needed include (according to XOPEN) for definition of WIFEXITED and WEXITSTATUS. -- Markus S.