mirror of https://github.com/python/cpython.git
603c6831d0
Changes enabling Python to compile under OS/2 Visual Age C++. |
||
---|---|---|
.. | ||
_tkinter.def | ||
config.c | ||
getpathp.c | ||
makefile | ||
makefile.omk | ||
pyconfig.h | ||
python.def | ||
readme.txt |
readme.txt
IBM VisualAge C/C++ for OS/2 ============================ To build Python for OS/2, change into ./os2vacpp and issue an 'NMAKE' command. This will build a PYTHON15.DLL containing the set of Python modules listed in config.c and a small PYTHON.EXE to start the interpreter. By changing the C compiler flag /Gd- in the makefile to /Gd+, you can reduce the size of these by causing Python to dynamically link to the C runtime DLLs instead of including their bulk in your binaries. However, this means that any system on which you run Python must have the VAC++ compiler installed in order to have those DLLs available. During the build process you may see a couple of harmless warnings: From the C Compiler, "No function prototype given for XXX", which comes from the use of K&R parameters within Python for portability. From the ILIB librarian, "Module Not Found (XXX)", which comes from its attempt to perform the (-+) operation, which removes and then adds a .OBJ to the library. The first time a build is done, it obviously cannot remove what is not yet built. This build includes support for most Python functionality as well as TCP/IP sockets. It omits the Posix ability to 'fork' a process but supports threads using OS/2 native capabilities. I have tried to support everything possible but here are a few usage notes. -- os.popen() Usage Warnings With respect to my implementation of popen() under OS/2: import os fd = os.popen("pkzip.exe -@ junk.zip", 'wb') fd.write("file1.txt\n") fd.write("file2.txt\n") fd.write("file3.txt\n") fd.write("\x1a") # Should Not Be Necessary But Is fd.close() There is a bug, either in the VAC++ compiler or OS/2 itself, where the simple closure of the write-side of a pipe -to- a process does not send an EOF to that process. I find I must explicitly write a control-Z (EOF) before closing the pipe. This is not a problem when using popen() in read mode. One other slight difference with my popen() is that I return None from the close(), instead of the Unix convention of the return code of the spawned program. I could find no easy way to do this under OS/2. -- BEGINLIBPATH/ENDLIBPATH With respect to environment variables, this OS/2 port supports the special-to-OS/2 magic names of 'BEGINLIBPATH' and 'ENDLIBPATH' to control where to load conventional DLLs from. Those names are intercepted and converted to calls on the OS/2 kernel APIs and are inherited by child processes, whether Python-based or not. A few new attributes have been added to the os module: os.meminstalled # Count of Bytes of RAM Installed on Machine os.memkernel # Count of Bytes of RAM Reserved (Non-Swappable) os.memvirtual # Count of Bytes of Virtual RAM Possible os.timeslice # Duration of Scheduler Timeslice, in Milliseconds os.maxpathlen # Maximum Length of a Path Specification, in chars os.maxnamelen # Maximum Length of a Single Dir/File Name, in chars os.version # Version of OS/2 Being Run e.g. "4.00" os.revision # Revision of OS/2 Being Run (usually zero) os.bootdrive # Drive that System Booted From e.g. "C:" # (useful to find the CONFIG.SYS used to boot with) -- Using Python as the Default OS/2 Batch Language Note that OS/2 supports the Unix technique of putting the special comment line at the time of scripts e.g. "#!/usr/bin/python" in a different syntactic form. To do this, put your script into a file with a .CMD extension and added 'extproc' to the top as follows: extproc C:\Python\Python.exe -x import os print "Hello from Python" The '-x' option tells Python to skip the first line of the file while processing the rest as normal Python source. -- Suggested Environment Variable Setup With respect to the environment variables for Python, I use the following setup: Set PYTHONHOME=E:\Tau\Projects\Python;D:\DLLs Set PYTHONPATH=.;E:\Tau\Projects\Python\Lib; \ E:\Tau\Projects\Python\Lib\plat-win The EXEC_PREFIX (optional second pathspec on PYTHONHOME) is where you put any Python extension DLLs you may create/obtain. There are none provided with this release. -- Contact Info If you have questions, suggestions or problems specifically with the OS/2 VAC++ port of Python, please contact me at: Jeff Rush <jrush@summit-research.com>. I support no other platform but OS/2 (and eventually AmigaDOS).