This is a port of Python 2.6 to OS/2 using the EMX development tools ========================================================================= What's new since the previous release ------------------------------------- Another day, another version... Licenses and info about Python and EMX -------------------------------------- Please read the file README.Python-2.6 included in this package for information about Python 2.6. This file is the README file from the Python 2.6 source distribution available via http://www.python.org/ and its mirrors. The file LICENCE.Python-2.6 is the text of the Licence from the Python 2.6 source distribution. Note that the EMX package that this package depends on is released under the GNU General Public Licence. Please refer to the documentation accompanying the EMX Runtime libraries for more information about the implications of this. A copy of version 2 of the GPL is included as the file COPYING.gpl2. Readline and GDBM are covered by the GNU General Public Licence. I think Eberhard Mattes' porting changes to BSD DB v1.85 are also GPL'ed (BSD DB itself is BSD Licenced). ncurses and expat appear to be covered by MIT style licences - please refer to the source distributions for more detail. zlib is distributable under a very free license. GNU UFC is under the GNU LGPL (see file COPYING.lib). My patches to the Python-2.x source distributions, and any other packages used in this port, are placed in the public domain. This software is provided 'as-is', without any express or implied warranty. In no event will the author be held liable for any damages arising from the use of the software. I do hope however that it proves useful to someone. Other ports ----------- There have been ports of previous versions of Python to OS/2. The best known would be that by Jeff Rush, most recently of version 1.5.2. Jeff used IBM's Visual Age C++ (v3) for his ports, and his patches have been included in the Python 2.6 source distribution. Andy Zabolotny implemented a port of Python v1.5.2 using the EMX development tools. His patches against the Python v1.5.2 source distribution have become the core of this port, and without his efforts this port wouldn't exist. Andy's port also appears to have been compiled with his port of gcc 2.95.2 to EMX, which I have but have chosen not to use for the binary distribution of this port (see item 16 of the "YOU HAVE BEEN WARNED" section below). It is possible to have these earlier ports still usable after installing this port - see the README.os2emx.multiple_versions file, contributed by Dr David Mertz, for a suggested approach to achieving this. Software requirements --------------------- This package requires the EMX Runtime package, available from the Hobbes (http://hobbes.nmsu.edu/) and LEO (http://archiv.leo.org/) archives of OS/2 software. I have used EMX version 0.9d fix04 in developing this port. My development system is running OS/2 v4 with fixpack 12. 3rd party software which has been linked into dynamically loaded modules: - ncurses (see http://dickey.his.com/ for more info, v5.2) - GNU Readline (Kai Uwe Rommel's port available from Hobbes or LEO, v2.1) - GNU GDBM (Kai Uwe Rommel's port available from Hobbes or LEO, v1.7.3) - zlib (derived from Hung-Chi Chu's port of v1.1.3, v1.1.4) - expat (distributed with Python, v1.95.6) - GNU UFC (Kai Uwe Rommel's port available from LEO, v2.0.4) About this port --------------- I have attempted to make this port as complete and functional as I can, notwithstanding the issues in the "YOU HAVE BEEN WARNED" section below. Core components: Python.exe is linked as an a.out executable, ie using EMX method E1 to compile & link the executable. This is so that fork() works (see "YOU HAVE BEEN WARNED" item 1). Python26.dll is created as a normal OMF DLL, with an OMF import library and module definition file. There is also an a.out (.a) import library to support linking the DLL to a.out executables. The DLL requires the EMX runtime DLLs. This port has been built with complete support for multithreading. Modules: With the exception of modules that have a significant code size, or are not recommended or desired for normal use, the standard modules are now built into the core DLL rather than configured as dynamically loadable modules. This is for both reasons of performance (startup time) and memory use (lots of small DLLs fragment the address space). I haven't yet changed the building of Python's dynamically loadable modules over to using the DistUtils. See "YOU HAVE BEEN WARNED" item 3 for notes about the fcntl module, and "YOU HAVE BEEN WARNED" item 10 for notes about the pwd and grp modules. This port supports case sensitive module import semantics, matching the Windows release. This can be deactivated by setting the PYTHONCASEOK environment variable (the value doesn't matter) - see "YOU HAVE BEEN WARNED" item 12. Optional modules: Where I've been able to locate the required 3rd party packages already ported to OS/2, I've built and included them. These include ncurses (_curses, _curses_panel), BSD DB (bsddb185), GNU GDBM (gdbm, dbm), zlib (zlib), GNU Readline (readline), and GNU UFC (crypt). Expat is now included in the Python release sourceball, and the pyexpat module is always built. I have built these modules statically linked against the 3rd party libraries. Unfortunately my attempts to use the dll version of GNU readline have been a dismal failure, in that when the dynamically linked readline module is active other modules immediately provoke a core dump when imported. Only the BSD DB package (part of the BSD package distributed with EMX) needs source modifications to be used for this port, pertaining to use of errno with multithreading. The other packages, except for ncurses and zlib, needed Makefile changes for multithreading support but no source changes. The _curses_panel module is a potential problem - see "YOU HAVE BEEN WARNED" item 13. Upstream source patches: No updates to the Python 2.6 release have become available. Eberhard Mattes' EMXFIX04 update to his EMX 0.9d tools suite includes bug fixes for the BSD DB library. The bsddb module included in this port incorporates these fixes. Library and other distributed Python code: The Python standard library lives in the Lib directory. All the standard library code included with the Python 2.6 source distribution is included in the binary archive, with the exception of the dos-8x3 and tkinter subdirectories which have been omitted to reduce the size of the binary archive - the dos-8x3 components are unnecessary duplicates and Tkinter is not supported by this port (yet). All the plat-* subdirectories in the source distribution have also been omitted, except for the plat-os2emx subdirectory. The Tools and Demo directories contain a collection of Python scripts. To reduce the size of the binary archive, the Demo/sgi, Demo/Tix, Demo/tkinter, Tools/audiopy and Tools/IDLE subdirectories have been omitted as not being supported by this port. The Misc directory has also been omitted. All subdirectories omitted from the binary archive can be reconstituted from the Python 2.6 source distribution, if desired. Support for building Python extensions: The Config subdirectory contains the files describing the configuration of the interpreter and the Makefile, import libraries for the Python DLL, and the module definition file used to create the Python DLL. The Include subdirectory contains all the standard Python header files needed for building extensions. As I don't have the Visual Age C++ compiler, I've made no attempt to have this port support extensions built with that compiler. Packaging --------- This port is packaged as follows: - python-2.6-os2emx-bin-03????.zip (binaries, library modules) - python-2.6-os2emx-src-03???? (patches+makefiles for non-Python code) As all the Python specific patches for the port are now part of the Python release tarball, only the patches and makefiles involved in building external libraries for optional extensions are included in the source archive. Documentation for the Python language, as well as the Python 2.6 source distibution, can be obtained from the Python website (http://www.python.org/) or the Python project pages at Sourceforge (http://sf.net/projects/python/). Installation ------------ Obtain and install, as per the included instructions, the EMX runtime package. Unpack this archive, preserving the subdirectories, in the root directory of the drive where you want Python to live. Add the Python directory (eg C:\Python26) to the PATH and LIBPATH variables in CONFIG.SYS. You should then set the PYTHONHOME and PYTHONPATH environment variables in CONFIG.SYS. PYTHONHOME should be set to Python's top level directory. PYTHONPATH should be set to the semicolon separated list of principal Python library directories. I use: SET PYTHONHOME=F:/Python26 SET PYTHONPATH=F:/Python26/Lib;F:/Python26/Lib/plat-os2emx; F:/Python26/Lib/lib-dynload;F:/Python26/Lib/site-packages NOTE!: the PYTHONPATH setting above is linewrapped for this document - it should all be on one line in CONFIG.SYS! If you wish to use the curses module, you should set the TERM and TERMINFO environment variables appropriately. If you don't already have ncurses installed, I have included a copy of the EMX subset of the Terminfo database included with the ncurses-5.2 source distribution. This can be used by setting the TERMINFO environment variable to the path of the Terminfo subdirectory below the Python home directory. On my system this looks like: SET TERMINFO=F:/Python26/Terminfo For the TERM environment variable, I would try one of the following: SET TERM=ansi SET TERM=os2 SET TERM=window You will have to reboot your system for these changes to CONFIG.SYS to take effect. If you wish to compile all the included Python library modules to bytecode, you can change into the Python home directory and run the COMPILEALL.CMD batch file. You can execute the regression tests included with the Python 2.6 source distribution by changing to the Python 2.6 home directory and executing the REGRTEST.CMD batch file. The following tests are known to fail at this time: - test_mhlib (I don't know of any port of MH to OS/2); - test_strptime (see "YOU HAVE BEEN WARNED" item 22); - test_time (see "YOU HAVE BEEN WARNED" item 22); - test_posixpath (see "YOU HAVE BEEN WARNED" item 23). Note that some of the network related tests expect the loopback interface (interface "lo", with IP address 127.0.0.1) to be enabled, which from my experience is not the default configuration. Additionally, test_popen2 expects the "cat" utility (such as found in ports of the GNU tools) to be installed. Building from source -------------------- With the EMX port now checked into Python's CVS repository, the build infrastructure is part of the Python release sourceball. Prerequisites First and foremost, you need an operational EMX development installation - EMX v0.9d with fix04 (the latest at time of writing) & the gcc 2.8.1 compiler released by Eberhard Mattes is the recommended setup. If you have a different version of gcc installed, see "YOU HAVE BEEN WARNED" item 16. Other items of software required:- - GNU make (I'm using v3.76.1) - rm, cp, mkdir from the GNU file utilities package - GNU find - GNU sed Procedure 0. all changes mentioned apply to files in the PC/os2emx subdirectory of the Python release source tree. make is also executed from this directory, so change into this directory before proceeding. 1. decide if you need to change the location of the Python installation. If you wish to do this, set the value of the Makefile variable LIB_DIR to the directory you wish to use for PYTHONHOME (eg /usr/local/lib/python2.6). If you want Python to find its library without the PYTHONHOME environment variable set, set the value of the Makefile variable FIXED_PYHOME to "yes" (uncomment the appropriate line). 2. If you wish the Python executables (python.exe, pythonpm.exe & pgen.exe) to be installed in a directory other than the PYTHONHOME directory, set the value of the Makefile variable EXE_DIR to the appropriate directory. 3. If you wish the Python core DLL (python27.dll) to be installed in a directory other than the directory in which the Python executables are installed (by default, the PYTHONHOME directory), set the value of the Makefile variable DLL_DIR to the appropriate directory. This DLL must be placed in a directory on the system's LIBPATH, or that gets set with BEGINLIBPATH or ENDLIBPATH. 4. If you have installed any of the libraries that can be used to build optional Python modules, set the value of the relevant HAVE_ Makefile variable to "yes". The Makefile currently supports: library Makefile variable ........................................ zlib (1.1.4) HAVE_ZLIB GNU UltraFast Crypt HAVE_UFC Tcl/Tk HAVE_TCLTK (not known to work) GNU Readline HAVE_GREADLINE BSD DB (v1.85) HAVE_BSDDB ncurses HAVE_NCURSES GNU gdbm HAVE_GDBM libbz2 HAVE_BZ2 OpenSSL HAVE_OPENSSL Please note that you need to check that what you have installed is compatible with Python's build options. In particular, the BSD DB v1.85 library needs to be rebuilt with a source patch for multithread support (doesn't change the library's reentrant status but allows it to be linked to Python which is multithreaded). Widely available binary packages of other librarys & DLLs are not built/linked with multithread support. Beware! Also note that the Makefile currently expects any libraries to be found with the default library search path. You may need to add -L switches to the LDFLAGS Makefile variable if you have installed libraries in directories not in the default search path (which can be controlled by the LIBRARY_PATH environment variable used by EMX). 5. make It is usually a good idea to redirect the stdout and stderr streams of the make process to log files, so that you can review any messages. 6. make test This runs the Python regression tests, and completion is a sign of a usable build. You should check the list of skipped modules to ensure that any optional modules you selected have been built; checking the list of failures against the list of known failures elsewhere in this document is also prudent. 7. make install >>>>>> NOT YET COMPLETE <<<<<< 8. change to a directory outside the Python source tree and start Python. Check the version and build date to confirm satisfactory installation. YOU HAVE BEEN WARNED!! ---------------------- I know about a number of nasties in this port. 1. Eberhard Mattes, author of EMX, writes in his documentation that fork() is very inefficient in the OS/2 environment. It also requires that the executable be linked in a.out format rather than OMF. Use the os.exec and/or the os.spawn family of functions where possible. 2. In the absence of GNU Readline, terminating the interpreter requires a control-Z (^Z) followed by a carriage return. Jeff Rush documented this problem in his Python 1.5.2 port. With Readline, a control-D (^D) works as per the standard Unix environment. 3. EMX only has a partial implementation of fcntl(). The fcntl module in this port supports what EMX supports. If fcntl is important to you, please review the EMX C Library Reference (included in .INF format in the EMXVIEW.ZIP archive as part of the complete EMX development tools suite). Because of other side-effects I have modified the test_fcntl.py test script to deactivate the exercising of the missing functionality. 4. the PyBSDDB3 module has been imported into the Python standard library, with the intent of superceding the BSDDB 1.85 module (bsddb). As I don't yet have a satisfactory port of Sleepcat's more recent DB library (3.3.x/4.0.x/4.1.x), I haven't included a binary of this module. I have left the Python part of the PyBSDDB package in this distribution for completeness. 5. As a consequence of the PyBSDDB3 module being imported, the former BSD DB (bsddb) module, linked against the DB v1.85 library from EMX, has been renamed bsddb185. The bsddb185 module will not be built by default on most platforms, but in the absence of a PyBSDDB3 module I have retained it in the EMX port. Version 1.85 of the DB library is widely known to have bugs, although some patches have become available (and are incorporated into the included bsddb185 module). Unless you have problems with software licenses which would rule out GDBM (and the dbm module because it is linked against the GDBM library) or need it for file format compatibility, you may be better off deleting it and relying on GDBM. Any code you have which uses the v1.85 bsddb module can be modified to use the renamed module by changing import bsddb to import bsddb185 as bsddb 6. The readline module has been linked against ncurses rather than the termcap library supplied with EMX. 7. I have configured this port to use "/" as the preferred path separator character, rather than "\" ('\\'), in line with the convention supported by EMX. Backslashes are still supported of course, and still appear in unexpected places due to outside sources that don't get normalised. 8. While the DistUtils components are now functional, other packaging/binary handling tools and utilities such as those included in the Demo and Tools directories - freeze in particular - are unlikely to work. If you do get them going, I'd like to know about your success. 9. I haven't set out to support the [BEGIN|END]LIBPATH functionality supported by one of the earlier ports (Rush's??). If it works let me know. 10. As a result of the limitations imposed by EMX's library routines, the standard extension module pwd only synthesises a simple passwd database, and the grp module cannot be supported at all. I have written pure Python substitutes for pwd and grp, which can process real passwd and group files for those applications (such as MailMan) that require more than EMX emulates. I have placed pwd.py and grp.py in Lib/plat-os2emx, which is usually before Lib/lib-dynload (which contains pwd.pyd) in the PYTHONPATH. If you have become attached to what pwd.pyd supports, you can put Lib/lib-dynload before Lib/plat-os2emx in PYTHONPATH or delete/rename pwd.py & grp.py. pwd.py & grp.py support locating their data files by looking in the environment for them in the following sequence: pwd.py: $ETC_PASSWD (%ETC_PASSWD%) $ETC/passwd (%ETC%/passwd) $PYTHONHOME/Etc/passwd (%PYTHONHOME%/Etc/passwd) grp.py: $ETC_GROUP (%ETC_GROUP%) $ETC/group (%ETC%/group) $PYTHONHOME/Etc/group (%PYTHONHOME%/Etc/group) The ETC_PASSWD and ETC_GROUP environment variables are intended to allow support for multiple passwd/grp files, where other applications may not support as wide a variety of input variations (drive remappings, separators etc). Both modules support using either the ":" character (Unix standard) or ";" (OS/2, DOS, Windows standard) field separator character, and pwd.py implements the following drive letter conversions for the home_directory and shell fields (for the ":" separator only): $x -> x: x; -> x: Example versions of passwd and group are in the Etc subdirectory. The regression tests (test_pwd and test_grp) will fail if valid password and group files cannot be found, but should pass otherwise. Be aware that Python's pwd & group modules are for reading password and group information only. 11. EMX's termios routines don't support all of the functionality now exposed by the termios module - refer to the EMX documentation to find out what is supported. 12. The case sensitive import semantics introduced in Python 2.1 for other case insensitive but case preserving file/operating systems (Windows etc), have been incorporated into this port, and are active by default. Setting the PYTHONCASEOK environment variable (to any value) reverts to the previous (case insensitive) semantics. This can be an issue with some file management utilities that do not preserve the case of file and directory names. 13. Because I am statically linking ncurses, the _curses_panel module has potential problems arising from separate library data areas. To avoid this, I have configured the _curses_.pyd (imported as "_curses_panel") to import the ncurses symbols it needs from _curses.dll (which is the curses module, but with a .dll extension rather than .pyd so that the dynamic loader can actually import the symbols from it as a DLL). The site module (Lib/site.py) has code added to tweak BEGINLIBPATH so that _curses.dll is found when _curses_panel is imported. If you have problems attempting to use the _curses_panel support please let me know, and I'll have another look at this. 14. sys.platform reports "os2emx" instead of "os2". os.name still reports "os2". This change was to make it easier to distinguish between the VAC++ build (formerly maintained by Michael Muller) and the EMX build (this port), principally for DistUtils. 15. it appears that the %W substitution in the EMX strftime() routine has an off-by-one bug. strftime was listed as passing the regression tests in previous releases, but this fact appears to have been an oversight in the regression test suite. To fix this really requires a portable strftime routine - I'm looking into using one from FreeBSD, but its not ready yet. 16. I have successfully built this port with Andy Zabolotny's ports of pgcc 2.95 and gcc 3.2.1, in addition to EM's gcc 2.8.1. To use the bsddb185 module with the gcc 3.2.1 build, I had to recompile the DB library with gcc 3.2.1 - I don't know why, but trying to import the module built against a DB library compiled with gcc 2.8.1 would result in a SYS3175 error. I have not attempted to compile Python with any version of gcc prior to v2.8.1. This release sees the default optimisation change to "-O3 -fomit-frame-pointer -mprobe". This works fine too for pgcc 2.95 but not for gcc 3.2.1. With gcc 3.2.1, -O3 causes 2 unexpected test failures: test_format and test_unicode. Both these tests pass if -O2 is instead of -O3 with this compiler, and the performance difference is negligible (in contrast to gcc 2.8.1 and pgcc 2.95, where the performance difference between the 2 optimisation settings approaches 10%). 17. os.spawnv() and os.spawnve() expose EMX's library routines rather than use the emulation in os.py. In order to make use of some of the features this makes available in the OS/2 environment, you should peruse the relevant EMX documentation (EMXLIB.INF in the EMXVIEW.ZIP archive accompanying the EMX archives on Hobbes or LEO). Be aware that I have exposed all the "mode" options supported by EMX, but there are combinations that either cannot be practically used by/in Python or have the potential to compromise your system's stability. 18. pythonpm.exe used to be just python.exe with the WINDOWAPI linker option set in the pythonpm.def file. In practice, this turns out to do nothing useful. I have written a replacement which wraps the Python DLL in a genuine Presentation Manager application. This version actually runs the Python interpreter in a separate thread from the PM shell, in order that PythonPM has a functioning message queue as good PM apps should. In its current state, PythonPM's window is hidden. It can be displayed, although it will have no content as nothing is ever written to the window. Only the "hide" button is available. Although the code has support for shutting PythonPM down when the Python interpreter is still busy (via the "control" menu), this is not well tested and given comments I've come across in EMX documentation suggesting that the thread killing operation has problems I would suggest caution in relying on this capability. PythonPM processes commandline parameters normally. The standard input, output and error streams are only useful if redirected, as PythonPM's window is not a console in any form and so cannot accept or display anything. This means that the -i option is ineffective. Because the Python thread doesn't create its own message queue, creating PM Windows and performing most PM operations is not possible from within this thread. How this will affect supporting PM extensions (such as Tkinter using a PM port of Tcl/Tk, or wxPython using the PM port of WxWindows) is still being researched. Note that os.fork() _DOES_NOT_WORK_ in PythonPM - SYS3175s are the result of trying. os.spawnv() _does_ work. PythonPM passes all regression tests that the standard Python interpreter (python.exe) passes, with the exception of test_fork1 and test_socket which both attempt to use os.fork(). I very much want feedback on the performance, behaviour and utility of PythonPM. I would like to add a PM console capability to it, but that will be a non-trivial effort. I may be able to leverage the code in Illya Vaes' Tcl/Tk port, which would make it easier. 19. os.chdir() uses EMX's _chdir2(), which supports changing both drive and directory at once. Similarly, os.getcwd() uses EMX's _getcwd() which returns drive as well as path. 20. pyconfig.h is installed in the Include subdirectory with all other include files. 21. the default build explicitly sets the number of file handles available to a Python process to 250. EMX default is 40, which is insufficient for the tempfile regression test (test_tempfile) which tries to create 100 temporary files. This setting can be overridden via the EMXOPT environment variable: set EMXOPT=-h250 is equivalent to the setting currently used. The emxbind utility (if you have it installed) can also be used to permanently change the setting in python.exe - please refer to the EMX documentation for more information. 22. a pure python strptime module is now part of the Python standard library, superceding a platform specific extension module. This module leverages the strftime module, and as a result test_strptime fails due to the EMX strftime bug in item 20 above. 23. test_posixpath attempts to exercise various Posix path related functionality. Most of the sub-tests pass, but the "ismount" and "samestat" subtests fail: - EMX provides not satisfactory mount point emulation, so "ismount" cannot succeed; - EMX documents that successive stat() calls will produce different results, so "samestat" cannot succeed. test_posixpath should skip these tests on EMX. 24. I have reports of BitTorrent not working. It appears that the EMX select() emulation, possibly in concert with bugs in the TCP/IP stack, runs into problems under the stress imposed by this application. I think it suffices to say that BitTorrent is a fair stress test of a system's networking capability. 25. In the absence of an EMX implementation of the link() function, I've implemented a crude Python emulation, in the file Lib/plat-os2emx/_emx_link.py. This is imported into the os module, and becomes available as os.link() in the normal way. The emulation copies the source file in binary mode, and will fail if disk space is exhausted. The call fails if the target already exists. There are no guarantees to thread safety with this emulation - beware! The emulation was written to support a link() based file locking system used in GNU Mailman. 26. AF_UNIX sockets, otherwise known as Unix domain sockets, are now supported. Unfortunately, there are some traps arising from the implementation in IBM's TCP/IP stack:- - the path name must start with '\\socket\\' ('/socket/' won't work!), with the length of the full path name less than 108 characters; - unlike Unix, the socket endpoints don't exist in the filesystem; - by default, sockets are in binary mode. 27. As of Python 2.4, the mpz, rotor and xreadlines modules have been dropped from the Python source tree. 28. The subprocess module was added to the standard library relatively late in the 2.4 development cycle. Unfortunately I haven't had the round tuits to adapt the module to the EMX environment yet, and test_subprocess has a number of failures as a result. 29. The default stack size for threads has been 64k. This is proving insufficient for some codebases, such as Zope. The thread stack size still defaults to 64k, but this can now be increased via the stack_size() function exposed by the threading & thread modules as well as by defining THREAD_STACK_SIZE to an appropriate value in the Makefile (which contains a commented out definition for 128kB thread stacks). I have seen references to heavy Zope/Plone usage requiring 1MB thread stacks on FreeBSD and Linux, but doubt that for most likely usage on OS/2 that more than 256kB is necessary. The size of the required stacks (main and thread) can vary significantly depending on which version of gcc is used along with the compiler optimisations selected. Note that the main thread stack size is set during linking and is currently 2MB. ... probably other issues that I've not encountered, or don't remember :-( If you encounter other difficulties with this port, which can be characterised as peculiar to this port rather than to the Python release, I would like to hear about them. However I cannot promise to be able to do anything to resolve such problems. See the Contact section below... To do... -------- In no particular order of apparent importance or likelihood... - support Tkinter and/or alternative GUI (wxWindows??) Credits ------- In addition to people identified above, I'd like to thank: - the BDFL, Guido van Rossum, and crew for Python; - Dr David Mertz, for trying out a pre-release of this port; - the Python-list/comp.lang.python community; - John Poltorak, for input about pwd/grp. Contact ------- Constructive feedback, negative or positive, about this port is welcome and should be addressed to me at the e-mail addresses below. I have a private mailing list for announcements of fixes & updates to this port. If you wish to receive such e-mail announcments, please send me an e-mail requesting that you be added to this list. Andrew MacIntyre E-mail: andymac@bullseye.apana.org.au, or andymac@pcug.org.au Web: http://www.andymac.org/ 28 January, 2008.