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1IBM VisualAge C/C++ for OS/2 2============================ 3 4To build Python for OS/2, change into ./os2vacpp and issue an 'NMAKE' 5command. This will build a PYTHON15.DLL containing the set of Python 6modules listed in config.c and a small PYTHON.EXE to start the 7interpreter. 8 9By changing the C compiler flag /Gd- in the makefile to /Gd+, you can 10reduce the size of these by causing Python to dynamically link to the 11C runtime DLLs instead of including their bulk in your binaries. 12However, this means that any system on which you run Python must have 13the VAC++ compiler installed in order to have those DLLs available. 14 15During the build process you may see a couple of harmless warnings: 16 17 From the C Compiler, "No function prototype given for XXX", which 18 comes from the use of K&R parameters within Python for portability. 19 20 From the ILIB librarian, "Module Not Found (XXX)", which comes 21 from its attempt to perform the (-+) operation, which removes and 22 then adds a .OBJ to the library. The first time a build is done, 23 it obviously cannot remove what is not yet built. 24 25This build includes support for most Python functionality as well as 26TCP/IP sockets. It omits the Posix ability to 'fork' a process but 27supports threads using OS/2 native capabilities. I have tried to 28support everything possible but here are a few usage notes. 29 30 31-- os.popen() Usage Warnings 32 33With respect to my implementation of popen() under OS/2: 34 35 import os 36 37 fd = os.popen("pkzip.exe -@ junk.zip", 'wb') 38 fd.write("file1.txt\n") 39 fd.write("file2.txt\n") 40 fd.write("file3.txt\n") 41 fd.write("\x1a") # Should Not Be Necessary But Is 42 fd.close() 43 44There is a bug, either in the VAC++ compiler or OS/2 itself, where the 45simple closure of the write-side of a pipe -to- a process does not 46send an EOF to that process. I find I must explicitly write a 47control-Z (EOF) before closing the pipe. This is not a problem when 48using popen() in read mode. 49 50One other slight difference with my popen() is that I return None 51from the close(), instead of the Unix convention of the return code 52of the spawned program. I could find no easy way to do this under 53OS/2. 54 55 56-- BEGINLIBPATH/ENDLIBPATH 57 58With respect to environment variables, this OS/2 port supports the 59special-to-OS/2 magic names of 'BEGINLIBPATH' and 'ENDLIBPATH' to 60control where to load conventional DLLs from. Those names are 61intercepted and converted to calls on the OS/2 kernel APIs and 62are inherited by child processes, whether Python-based or not. 63 64A few new attributes have been added to the os module: 65 66 os.meminstalled # Count of Bytes of RAM Installed on Machine 67 os.memkernel # Count of Bytes of RAM Reserved (Non-Swappable) 68 os.memvirtual # Count of Bytes of Virtual RAM Possible 69 os.timeslice # Duration of Scheduler Timeslice, in Milliseconds 70 os.maxpathlen # Maximum Length of a Path Specification, in chars 71 os.maxnamelen # Maximum Length of a Single Dir/File Name, in chars 72 os.version # Version of OS/2 Being Run e.g. "4.00" 73 os.revision # Revision of OS/2 Being Run (usually zero) 74 os.bootdrive # Drive that System Booted From e.g. "C:" 75 # (useful to find the CONFIG.SYS used to boot with) 76 77 78-- Using Python as the Default OS/2 Batch Language 79 80Note that OS/2 supports the Unix technique of putting the special 81comment line at the time of scripts e.g. "#!/usr/bin/python" in 82a different syntactic form. To do this, put your script into a file 83with a .CMD extension and added 'extproc' to the top as follows: 84 85 extproc C:\Python\Python.exe -x 86 import os 87 print "Hello from Python" 88 89The '-x' option tells Python to skip the first line of the file 90while processing the rest as normal Python source. 91 92 93-- Suggested Environment Variable Setup 94 95With respect to the environment variables for Python, I use the 96following setup: 97 98 Set PYTHONHOME=E:\Tau\Projects\Python;D:\DLLs 99 Set PYTHONPATH=.;E:\Tau\Projects\Python\Lib; \ 100 E:\Tau\Projects\Python\Lib\plat-win 101 102The EXEC_PREFIX (optional second pathspec on PYTHONHOME) is where 103you put any Python extension DLLs you may create/obtain. There 104are none provided with this release. 105 106 107-- Contact Info 108 109Jeff Rush is no longer supporting the VACPP port :-( 110 111I don't have the VACPP compiler, so can't reliably maintain this port. 112 113Anyone with VACPP who can contribute patches to keep this port buildable 114should upload them to the Python Patch Manager at Sourceforge and 115assign them to me for review/checkin. 116 117Andrew MacIntyre 118aimacintyre at users.sourceforge.net 119August 18, 2002.