/PC/os2emx/README.os2emx

  1This is a port of Python 2.6 to OS/2 using the EMX development tools
  2=========================================================================
  3
  4What's new since the previous release
  5-------------------------------------
  6
  7Another day, another version...
  8
  9
 10Licenses and info about Python and EMX
 11--------------------------------------
 12
 13Please read the file README.Python-2.6 included in this package for 
 14information about Python 2.6.  This file is the README file from the 
 15Python 2.6 source distribution available via http://www.python.org/ 
 16and its mirrors.  The file LICENCE.Python-2.6 is the text of the Licence 
 17from the Python 2.6 source distribution.
 18
 19Note that the EMX package that this package depends on is released under 
 20the GNU General Public Licence.  Please refer to the documentation 
 21accompanying the EMX Runtime libraries for more information about the 
 22implications of this.  A copy of version 2 of the GPL is included as the 
 23file COPYING.gpl2.
 24
 25Readline and GDBM are covered by the GNU General Public Licence.  I think 
 26Eberhard Mattes' porting changes to BSD DB v1.85 are also GPL'ed (BSD DB 
 27itself is BSD Licenced).  ncurses and expat appear to be covered by MIT 
 28style licences - please refer to the source distributions for more detail.  
 29zlib is distributable under a very free license.  GNU UFC is under the 
 30GNU LGPL (see file COPYING.lib).
 31
 32My patches to the Python-2.x source distributions, and any other packages 
 33used in this port, are placed in the public domain.
 34
 35This software is provided 'as-is', without any express or implied warranty.
 36In no event will the author be held liable for any damages arising from the 
 37use of the software.
 38
 39I do hope however that it proves useful to someone.
 40
 41
 42Other ports
 43-----------
 44
 45There have been ports of previous versions of Python to OS/2.
 46
 47The best known would be that by Jeff Rush, most recently of version 
 481.5.2.  Jeff used IBM's Visual Age C++ (v3) for his ports, and his 
 49patches have been included in the Python 2.6 source distribution.
 50
 51Andy Zabolotny implemented a port of Python v1.5.2 using the EMX 
 52development tools.  His patches against the Python v1.5.2 source 
 53distribution have become the core of this port, and without his efforts 
 54this port wouldn't exist.  Andy's port also appears to have been 
 55compiled with his port of gcc 2.95.2 to EMX, which I have but have 
 56chosen not to use for the binary distribution of this port (see item 16 
 57of the "YOU HAVE BEEN WARNED" section below).
 58
 59It is possible to have these earlier ports still usable after installing 
 60this port - see the README.os2emx.multiple_versions file, contributed by
 61Dr David Mertz, for a suggested approach to achieving this.
 62
 63
 64Software requirements
 65---------------------
 66
 67This package requires the EMX Runtime package, available from the 
 68Hobbes (http://hobbes.nmsu.edu/) and LEO (http://archiv.leo.org/) 
 69archives of OS/2 software.  I have used EMX version 0.9d fix04 in 
 70developing this port.
 71
 72My development system is running OS/2 v4 with fixpack 12.
 73
 743rd party software which has been linked into dynamically loaded modules:
 75- ncurses      (see http://dickey.his.com/ for more info, v5.2)
 76- GNU Readline (Kai Uwe Rommel's port available from Hobbes or LEO, v2.1)
 77- GNU GDBM     (Kai Uwe Rommel's port available from Hobbes or LEO, v1.7.3)
 78- zlib         (derived from Hung-Chi Chu's port of v1.1.3, v1.1.4)
 79- expat        (distributed with Python, v1.95.6)
 80- GNU UFC      (Kai Uwe Rommel's port available from LEO, v2.0.4)
 81
 82
 83About this port
 84---------------
 85
 86I have attempted to make this port as complete and functional as I can, 
 87notwithstanding the issues in the "YOU HAVE BEEN WARNED" section below.
 88
 89Core components:
 90
 91Python.exe is linked as an a.out executable, ie using EMX method E1 
 92to compile & link the executable.  This is so that fork() works (see 
 93"YOU HAVE BEEN WARNED" item 1).
 94
 95Python26.dll is created as a normal OMF DLL, with an OMF import 
 96library and module definition file.  There is also an a.out (.a) import 
 97library to support linking the DLL to a.out executables.  The DLL 
 98requires the EMX runtime DLLs.
 99
100This port has been built with complete support for multithreading.
101
102Modules:
103
104With the exception of modules that have a significant code size, or are 
105not recommended or desired for normal use, the standard modules are now 
106built into the core DLL rather than configured as dynamically loadable 
107modules.  This is for both reasons of performance (startup time) and 
108memory use (lots of small DLLs fragment the address space).
109
110I haven't yet changed the building of Python's dynamically loadable 
111modules over to using the DistUtils.
112
113See "YOU HAVE BEEN WARNED" item 3 for notes about the fcntl module, and 
114"YOU HAVE BEEN WARNED" item 10 for notes about the pwd and grp modules.
115
116This port supports case sensitive module import semantics, matching 
117the Windows release.  This can be deactivated by setting the PYTHONCASEOK 
118environment variable (the value doesn't matter) - see "YOU HAVE BEEN WARNED" 
119item 12.
120
121Optional modules:
122
123Where I've been able to locate the required 3rd party packages already 
124ported to OS/2, I've built and included them.
125
126These include ncurses (_curses, _curses_panel), BSD DB (bsddb185), 
127GNU GDBM (gdbm, dbm), zlib (zlib), GNU Readline (readline), and GNU UFC 
128(crypt).
129
130Expat is now included in the Python release sourceball, and the pyexpat 
131module is always built.
132
133I have built these modules statically linked against the 3rd party 
134libraries.  Unfortunately my attempts to use the dll version of GNU 
135readline have been a dismal failure, in that when the dynamically 
136linked readline module is active other modules immediately provoke a 
137core dump when imported.
138
139Only the BSD DB package (part of the BSD package distributed with EMX) 
140needs source modifications to be used for this port, pertaining to use 
141of errno with multithreading.
142
143The other packages, except for ncurses and zlib, needed Makefile changes 
144for multithreading support but no source changes.
145
146The _curses_panel module is a potential problem - see "YOU HAVE BEEN 
147WARNED" item 13.
148
149Upstream source patches:
150
151No updates to the Python 2.6 release have become available.
152
153Eberhard Mattes' EMXFIX04 update to his EMX 0.9d tools suite includes 
154bug fixes for the BSD DB library.  The bsddb module included in this 
155port incorporates these fixes.
156
157Library and other distributed Python code:
158
159The Python standard library lives in the Lib directory.  All the standard 
160library code included with the Python 2.6 source distribution is included 
161in the binary archive, with the exception of the dos-8x3 and tkinter 
162subdirectories which have been omitted to reduce the size of the binary 
163archive - the dos-8x3 components are unnecessary duplicates and Tkinter 
164is not supported by this port (yet).  All the plat-* subdirectories in the 
165source distribution have also been omitted, except for the plat-os2emx 
166subdirectory.
167
168The Tools and Demo directories contain a collection of Python scripts.  
169To reduce the size of the binary archive, the Demo/sgi, Demo/Tix, 
170Demo/tkinter, Tools/audiopy and Tools/IDLE subdirectories have been 
171omitted as not being supported by this port.  The Misc directory has 
172also been omitted.
173
174All subdirectories omitted from the binary archive can be reconstituted 
175from the Python 2.6 source distribution, if desired.
176
177Support for building Python extensions:
178
179The Config subdirectory contains the files describing the configuration 
180of the interpreter and the Makefile, import libraries for the Python DLL, 
181and the module definition file used to create the Python DLL.  The 
182Include subdirectory contains all the standard Python header files 
183needed for building extensions.
184
185As I don't have the Visual Age C++ compiler, I've made no attempt to 
186have this port support extensions built with that compiler.
187
188
189Packaging
190---------
191
192This port is packaged as follows:
193- python-2.6-os2emx-bin-03????.zip  (binaries, library modules)
194- python-2.6-os2emx-src-03????      (patches+makefiles for non-Python code)
195
196As all the Python specific patches for the port are now part of the 
197Python release tarball, only the patches and makefiles involved in 
198building external libraries for optional extensions are included in 
199the source archive.
200
201Documentation for the Python language, as well as the Python 2.6 
202source distibution, can be obtained from the Python website 
203(http://www.python.org/) or the Python project pages at Sourceforge 
204(http://sf.net/projects/python/).
205
206
207Installation
208------------
209
210Obtain and install, as per the included instructions, the EMX runtime 
211package.
212
213Unpack this archive, preserving the subdirectories, in the root directory 
214of the drive where you want Python to live.
215
216Add the Python directory (eg C:\Python26) to the PATH and LIBPATH 
217variables in CONFIG.SYS.
218
219You should then set the PYTHONHOME and PYTHONPATH environment variables 
220in CONFIG.SYS.
221
222PYTHONHOME should be set to Python's top level directory.  PYTHONPATH 
223should be set to the semicolon separated list of principal Python library 
224directories.
225I use:
226  SET PYTHONHOME=F:/Python26
227  SET PYTHONPATH=F:/Python26/Lib;F:/Python26/Lib/plat-os2emx;
228                 F:/Python26/Lib/lib-dynload;F:/Python26/Lib/site-packages
229
230NOTE!:  the PYTHONPATH setting above is linewrapped for this document - it 
231should all be on one line in CONFIG.SYS!
232
233If you wish to use the curses module, you should set the TERM and TERMINFO 
234environment variables appropriately.
235
236If you don't already have ncurses installed, I have included a copy of the 
237EMX subset of the Terminfo database included with the ncurses-5.2 source 
238distribution.  This can be used by setting the TERMINFO environment variable 
239to the path of the Terminfo subdirectory below the Python home directory.
240On my system this looks like:
241  SET TERMINFO=F:/Python26/Terminfo
242
243For the TERM environment variable, I would try one of the following:
244  SET TERM=ansi
245  SET TERM=os2
246  SET TERM=window
247
248You will have to reboot your system for these changes to CONFIG.SYS to take 
249effect.
250
251If you wish to compile all the included Python library modules to bytecode, 
252you can change into the Python home directory and run the COMPILEALL.CMD 
253batch file.
254
255You can execute the regression tests included with the Python 2.6 source 
256distribution by changing to the Python 2.6 home directory and executing the 
257REGRTEST.CMD batch file.  The following tests are known to fail at this 
258time:
259- test_mhlib (I don't know of any port of MH to OS/2);
260- test_strptime (see "YOU HAVE BEEN WARNED" item 22);
261- test_time (see "YOU HAVE BEEN WARNED" item 22);
262- test_posixpath (see "YOU HAVE BEEN WARNED" item 23).
263
264Note that some of the network related tests expect the loopback interface
265(interface "lo", with IP address 127.0.0.1) to be enabled, which from my
266experience is not the default configuration.  Additionally, test_popen2
267expects the "cat" utility (such as found in ports of the GNU tools) to
268be installed.
269
270
271Building from source
272--------------------
273
274With the EMX port now checked into Python's CVS repository, the build 
275infrastructure is part of the Python release sourceball.
276
277Prerequisites
278
279First and foremost, you need an operational EMX development installation - 
280EMX v0.9d with fix04 (the latest at time of writing) & the gcc 2.8.1 
281compiler released by Eberhard Mattes is the recommended setup.
282
283If you have a different version of gcc installed, see "YOU HAVE BEEN 
284WARNED" item 16.
285
286Other items of software required:-
287
288- GNU make (I'm using v3.76.1)
289- rm, cp, mkdir from the GNU file utilities package
290- GNU find
291- GNU sed
292
293Procedure
294
2950. all changes mentioned apply to files in the PC/os2emx subdirectory 
296   of the Python release source tree.  make is also executed from this 
297   directory, so change into this directory before proceeding.
298
2991. decide if you need to change the location of the Python installation.
300   If you wish to do this, set the value of the Makefile variable LIB_DIR 
301   to the directory you wish to use for PYTHONHOME 
302   (eg /usr/local/lib/python2.6).
303
304   If you want Python to find its library without the PYTHONHOME 
305   environment variable set, set the value of the Makefile variable 
306   FIXED_PYHOME to "yes" (uncomment the appropriate line).
307
3082. If you wish the Python executables (python.exe, pythonpm.exe & pgen.exe) 
309   to be installed in a directory other than the PYTHONHOME directory, set 
310   the value of the Makefile variable EXE_DIR to the appropriate directory.
311
3123. If you wish the Python core DLL (python26.dll) to be installed in a 
313   directory other than the directory in which the Python executables are 
314   installed (by default, the PYTHONHOME directory), set the value of the 
315   Makefile variable DLL_DIR to the appropriate directory.  This DLL must 
316   be placed in a directory on the system's LIBPATH, or that gets set 
317   with BEGINLIBPATH or ENDLIBPATH.
318
3194. If you have installed any of the libraries that can be used to build 
320   optional Python modules, set the value of the relevant HAVE_<package> 
321   Makefile variable to "yes".  The Makefile currently supports:
322
323   library               Makefile variable
324   ........................................
325   zlib (1.1.4)          HAVE_ZLIB
326   GNU UltraFast Crypt   HAVE_UFC
327   Tcl/Tk                HAVE_TCLTK (not known to work)
328   GNU Readline          HAVE_GREADLINE
329   BSD DB (v1.85)        HAVE_BSDDB
330   ncurses               HAVE_NCURSES
331   GNU gdbm              HAVE_GDBM
332   libbz2                HAVE_BZ2
333   OpenSSL               HAVE_OPENSSL
334
335   Please note that you need to check that what you have installed 
336   is compatible with Python's build options.  In particular, the 
337   BSD DB v1.85 library needs to be rebuilt with a source patch for 
338   multithread support (doesn't change the library's reentrant status 
339   but allows it to be linked to Python which is multithreaded).  
340   Widely available binary packages of other librarys & DLLs are 
341   not built/linked with multithread support.  Beware!
342
343   Also note that the Makefile currently expects any libraries to be 
344   found with the default library search path.  You may need to add 
345   -L switches to the LDFLAGS Makefile variable if you have installed 
346   libraries in directories not in the default search path (which can 
347   be controlled by the LIBRARY_PATH environment variable used by EMX).
348
3495. make
350
351   It is usually a good idea to redirect the stdout and stderr streams 
352   of the make process to log files, so that you can review any messages. 
353
3546. make test
355
356   This runs the Python regression tests, and completion is a sign of 
357   a usable build.  You should check the list of skipped modules to 
358   ensure that any optional modules you selected have been built; 
359   checking the list of failures against the list of known failures 
360   elsewhere in this document is also prudent.
361
3627. make install
363   >>>>>> NOT YET COMPLETE <<<<<< 
364
3658. change to a directory outside the Python source tree and start Python. 
366   Check the version and build date to confirm satisfactory installation.
367
368
369YOU HAVE BEEN WARNED!!
370----------------------
371
372I know about a number of nasties in this port.
373
3741.  Eberhard Mattes, author of EMX, writes in his documentation that fork() 
375is very inefficient in the OS/2 environment.  It also requires that the 
376executable be linked in a.out format rather than OMF.  Use the os.exec 
377and/or the os.spawn family of functions where possible.
378
3792.  In the absence of GNU Readline, terminating the interpreter requires a 
380control-Z (^Z) followed by a carriage return.  Jeff Rush documented this 
381problem in his Python 1.5.2 port.  With Readline, a control-D (^D) works 
382as per the standard Unix environment.
383
3843.  EMX only has a partial implementation of fcntl().  The fcntl module 
385in this port supports what EMX supports.  If fcntl is important to you, 
386please review the EMX C Library Reference (included in .INF format in the 
387EMXVIEW.ZIP archive as part of the complete EMX development tools suite).
388Because of other side-effects I have modified the test_fcntl.py test 
389script to deactivate the exercising of the missing functionality.
390
3914.  the PyBSDDB3 module has been imported into the Python standard
392library, with the intent of superceding the BSDDB 1.85 module (bsddb).
393As I don't yet have a satisfactory port of Sleepcat's more recent DB
394library (3.3.x/4.0.x/4.1.x), I haven't included a binary of this
395module.  I have left the Python part of the PyBSDDB package in this
396distribution for completeness.
397
3985.  As a consequence of the PyBSDDB3 module being imported, the former 
399BSD DB (bsddb) module, linked against the DB v1.85 library from EMX, 
400has been renamed bsddb185.  The bsddb185 module will not be built by 
401default on most platforms, but in the absence of a PyBSDDB3 module I 
402have retained it in the EMX port.
403
404Version 1.85 of the DB library is widely known to have bugs, although 
405some patches have become available (and are incorporated into the 
406included bsddb185 module).  Unless you have problems with software 
407licenses which would rule out GDBM (and the dbm module because it is 
408linked against the GDBM library) or need it for file format compatibility, 
409you may be better off deleting it and relying on GDBM.
410
411Any code you have which uses the v1.85 bsddb module can be modified to 
412use the renamed module by changing
413
414  import bsddb
415
416to
417
418  import bsddb185 as bsddb
419
4206.  The readline module has been linked against ncurses rather than the 
421termcap library supplied with EMX.
422
4237.  I have configured this port to use "/" as the preferred path separator 
424character, rather than "\" ('\\'), in line with the convention supported 
425by EMX.  Backslashes are still supported of course, and still appear in 
426unexpected places due to outside sources that don't get normalised.
427
4288.  While the DistUtils components are now functional, other 
429packaging/binary handling tools and utilities such as those included in
430the Demo and Tools directories - freeze in particular - are unlikely to 
431work.  If you do get them going, I'd like to know about your success.
432
4339.  I haven't set out to support the [BEGIN|END]LIBPATH functionality 
434supported by one of the earlier ports (Rush's??).  If it works let me know.
435
43610. As a result of the limitations imposed by EMX's library routines, the 
437standard extension module pwd only synthesises a simple passwd database, 
438and the grp module cannot be supported at all.
439
440I have written pure Python substitutes for pwd and grp, which can process 
441real passwd and group files for those applications (such as MailMan) that 
442require more than EMX emulates.  I have placed pwd.py and grp.py in 
443Lib/plat-os2emx, which is usually before Lib/lib-dynload (which contains 
444pwd.pyd) in the PYTHONPATH.  If you have become attached to what pwd.pyd 
445supports, you can put Lib/lib-dynload before Lib/plat-os2emx in PYTHONPATH 
446or delete/rename pwd.py & grp.py.
447
448pwd.py & grp.py support locating their data files by looking in the 
449environment for them in the following sequence:
450pwd.py:  $ETC_PASSWD             (%ETC_PASSWD%)
451         $ETC/passwd             (%ETC%/passwd)
452         $PYTHONHOME/Etc/passwd  (%PYTHONHOME%/Etc/passwd)
453grp.py:  $ETC_GROUP              (%ETC_GROUP%)
454         $ETC/group              (%ETC%/group)
455         $PYTHONHOME/Etc/group   (%PYTHONHOME%/Etc/group)
456
457The ETC_PASSWD and ETC_GROUP environment variables are intended to allow 
458support for multiple passwd/grp files, where other applications may not 
459support as wide a variety of input variations (drive remappings, 
460separators etc).
461
462Both modules support using either the ":" character (Unix standard) or 
463";" (OS/2, DOS, Windows standard) field separator character, and pwd.py 
464implements the following drive letter conversions for the home_directory and 
465shell fields (for the ":" separator only):
466         $x  ->  x:
467         x;  ->  x:
468
469Example versions of passwd and group are in the Etc subdirectory.  The 
470regression tests (test_pwd and test_grp) will fail if valid password and 
471group files cannot be found, but should pass otherwise.
472
473Be aware that Python's pwd & group modules are for reading password and 
474group information only.
475
47611. EMX's termios routines don't support all of the functionality now 
477exposed by the termios module - refer to the EMX documentation to find 
478out what is supported.
479
48012. The case sensitive import semantics introduced in Python 2.1 for other 
481case insensitive but case preserving file/operating systems (Windows etc), 
482have been incorporated into this port, and are active by default.  Setting 
483the PYTHONCASEOK environment variable (to any value) reverts to the 
484previous (case insensitive) semantics.  This can be an issue with some 
485file management utilities that do not preserve the case of file and
486directory names.
487
48813. Because I am statically linking ncurses, the _curses_panel 
489module has potential problems arising from separate library data areas.
490To avoid this, I have configured the _curses_.pyd (imported as 
491"_curses_panel") to import the ncurses symbols it needs from _curses.dll 
492(which is the curses module, but with a .dll extension rather than .pyd 
493so that the dynamic loader can actually import the symbols from it as a 
494DLL).
495
496The site module (Lib/site.py) has code added to tweak BEGINLIBPATH so
497that _curses.dll is found when _curses_panel is imported.  If you have
498problems attempting to use the _curses_panel support please let me know,
499and I'll have another look at this.
500
50114. sys.platform reports "os2emx" instead of "os2".  os.name still 
502reports "os2".  This change was to make it easier to distinguish between 
503the VAC++ build (formerly maintained by Michael Muller) and the EMX build 
504(this port), principally for DistUtils.
505
50615. it appears that the %W substitution in the EMX strftime() routine has 
507an off-by-one bug.  strftime was listed as passing the regression tests 
508in previous releases, but this fact appears to have been an oversight in 
509the regression test suite.  To fix this really requires a portable 
510strftime routine - I'm looking into using one from FreeBSD, but its not 
511ready yet.
512
51316. I have successfully built this port with Andy Zabolotny's ports of 
514pgcc 2.95 and gcc 3.2.1, in addition to EM's gcc 2.8.1.  To use the 
515bsddb185 module with the gcc 3.2.1 build, I had to recompile the DB library 
516with gcc 3.2.1 - I don't know why, but trying to import the module built 
517against a DB library compiled with gcc 2.8.1 would result in a SYS3175 
518error.
519
520I have not attempted to compile Python with any version of gcc prior to 
521v2.8.1.
522
523This release sees the default optimisation change to 
524"-O3 -fomit-frame-pointer -mprobe".  This works fine too for pgcc 2.95 
525but not for gcc 3.2.1.
526
527With gcc 3.2.1, -O3 causes 2 unexpected test failures: test_format and 
528test_unicode.  Both these tests pass if -O2 is instead of -O3 with this 
529compiler, and the performance difference is negligible (in contrast to 
530gcc 2.8.1 and pgcc 2.95, where the performance difference between the 
5312 optimisation settings approaches 10%).
532
53317.  os.spawnv() and os.spawnve() expose EMX's library routines rather 
534than use the emulation in os.py.
535
536In order to make use of some of the features this makes available in 
537the OS/2 environment, you should peruse the relevant EMX documentation 
538(EMXLIB.INF in the EMXVIEW.ZIP archive accompanying the EMX archives 
539on Hobbes or LEO).  Be aware that I have exposed all the "mode" options 
540supported by EMX, but there are combinations that either cannot be 
541practically used by/in Python or have the potential to compromise your 
542system's stability.
543
54418.  pythonpm.exe used to be just python.exe with the WINDOWAPI linker 
545option set in the pythonpm.def file.  In practice, this turns out to do 
546nothing useful.
547
548I have written a replacement which wraps the Python DLL in a genuine 
549Presentation Manager application.  This version actually runs the 
550Python interpreter in a separate thread from the PM shell, in order 
551that PythonPM has a functioning message queue as good PM apps should.
552In its current state, PythonPM's window is hidden.  It can be displayed, 
553although it will have no content as nothing is ever written to the 
554window.  Only the "hide" button is available.  Although the code 
555has support for shutting PythonPM down when the Python interpreter is 
556still busy (via the "control" menu), this is not well tested and given 
557comments I've come across in EMX documentation suggesting that the 
558thread killing operation has problems I would suggest caution in 
559relying on this capability.
560
561PythonPM processes commandline parameters normally.  The standard input, 
562output and error streams are only useful if redirected, as PythonPM's 
563window is not a console in any form and so cannot accept or display 
564anything.  This means that the -i option is ineffective.
565
566Because the Python thread doesn't create its own message queue, creating 
567PM Windows and performing most PM operations is not possible from within 
568this thread.  How this will affect supporting PM extensions (such as 
569Tkinter using a PM port of Tcl/Tk, or wxPython using the PM port of 
570WxWindows) is still being researched.
571
572Note that os.fork() _DOES_NOT_WORK_ in PythonPM - SYS3175s are the result 
573of trying.  os.spawnv() _does_ work.  PythonPM passes all regression tests 
574that the standard Python interpreter (python.exe) passes, with the exception 
575of test_fork1 and test_socket which both attempt to use os.fork().
576
577I very much want feedback on the performance, behaviour and utility of 
578PythonPM.  I would like to add a PM console capability to it, but that 
579will be a non-trivial effort.  I may be able to leverage the code in 
580Illya Vaes' Tcl/Tk port, which would make it easier.
581
58219.  os.chdir() uses EMX's _chdir2(), which supports changing both drive 
583and directory at once.  Similarly, os.getcwd() uses EMX's _getcwd() 
584which returns drive as well as path.
585
58620.  pyconfig.h is installed in the Include subdirectory with all 
587other include files.
588
58921.  the default build explicitly sets the number of file handles 
590available to a Python process to 250.  EMX default is 40, which is 
591insufficient for the tempfile regression test (test_tempfile) which 
592tries to create 100 temporary files.
593
594This setting can be overridden via the EMXOPT environment variable:
595  set EMXOPT=-h250
596is equivalent to the setting currently used.  The emxbind utility (if you 
597have it installed) can also be used to permanently change the setting in 
598python.exe - please refer to the EMX documentation for more information.
599
60022.  a pure python strptime module is now part of the Python standard
601library, superceding a platform specific extension module. This module
602leverages the strftime module, and as a result test_strptime fails
603due to the EMX strftime bug in item 20 above.
604
60523.  test_posixpath attempts to exercise various Posix path related
606functionality.  Most of the sub-tests pass, but the "ismount" and
607"samestat" subtests fail:
608- EMX provides not satisfactory mount point emulation, so "ismount"
609  cannot succeed;
610- EMX documents that successive stat() calls will produce different
611  results, so "samestat" cannot succeed.
612
613test_posixpath should skip these tests on EMX.
614
61524.  I have reports of BitTorrent not working.  It appears that the
616EMX select() emulation, possibly in concert with bugs in the TCP/IP
617stack, runs into problems under the stress imposed by this application.
618I think it suffices to say that BitTorrent is a fair stress test of a
619system's networking capability.
620
62125.  In the absence of an EMX implementation of the link() function, I've 
622implemented a crude Python emulation, in the file 
623Lib/plat-os2emx/_emx_link.py.  This is imported into the os module, and 
624becomes available as os.link() in the normal way.
625
626The emulation copies the source file in binary mode, and will fail if 
627disk space is exhausted. The call fails if the target already exists. 
628There are no guarantees to thread safety with this emulation - beware!
629
630The emulation was written to support a link() based file locking system 
631used in GNU Mailman.
632
63326.  AF_UNIX sockets, otherwise known as Unix domain sockets, are now
634supported.  Unfortunately, there are some traps arising from the
635implementation in IBM's TCP/IP stack:-
636- the path name must start with '\\socket\\' ('/socket/' won't work!),
637  with the length of the full path name less than 108 characters;
638- unlike Unix, the socket endpoints don't exist in the filesystem;
639- by default, sockets are in binary mode.
640
64127.  As of Python 2.4, the mpz, rotor and xreadlines modules have been 
642dropped from the Python source tree.
643
64428.  The subprocess module was added to the standard library relatively
645late in the 2.4 development cycle.  Unfortunately I haven't had the
646round tuits to adapt the module to the EMX environment yet, and
647test_subprocess has a number of failures as a result.
648
64929.  The default stack size for threads has been 64k.  This is proving
650insufficient for some codebases, such as Zope.  The thread stack size
651still defaults to 64k, but this can now be increased via the stack_size()
652function exposed by the threading & thread modules as well as by defining
653THREAD_STACK_SIZE to an appropriate value in the Makefile (which contains
654a commented out definition for 128kB thread stacks).  I have seen
655references to heavy Zope/Plone usage requiring 1MB thread stacks on
656FreeBSD and Linux, but doubt that for most likely usage on OS/2 that
657more than 256kB is necessary.  The size of the required stacks (main 
658and thread) can vary significantly depending on which version of gcc
659is used along with the compiler optimisations selected.  Note that the
660main thread stack size is set during linking and is currently 2MB.
661
662... probably other issues that I've not encountered, or don't remember :-(
663
664If you encounter other difficulties with this port, which can be 
665characterised as peculiar to this port rather than to the Python release,
666I would like to hear about them.  However I cannot promise to be able to do 
667anything to resolve such problems.  See the Contact section below...
668
669
670To do...
671--------
672
673In no particular order of apparent importance or likelihood...
674
675- support Tkinter and/or alternative GUI (wxWindows??)
676
677
678Credits
679-------
680
681In addition to people identified above, I'd like to thank:
682- the BDFL, Guido van Rossum, and crew for Python;
683- Dr David Mertz, for trying out a pre-release of this port;
684- the Python-list/comp.lang.python community;
685- John Poltorak, for input about pwd/grp.
686
687Contact
688-------
689
690Constructive feedback, negative or positive, about this port is welcome 
691and should be addressed to me at the e-mail addresses below.
692
693I have a private mailing list for announcements of fixes & updates to 
694this port.  If you wish to receive such e-mail announcments, please send 
695me an e-mail requesting that you be added to this list.
696
697Andrew MacIntyre
698E-mail: andymac@bullseye.apana.org.au, or andymac@pcug.org.au
699Web:    http://www.andymac.org/
700
70128 January, 2008.