zlib.so and libz.so and Python

[Skip Montanaro]

    DeepBleu> Python comes with zlib.so (for Sun OS).  But I noticed that on
    DeepBleu> the same machine, there is also libz.so.  Can someone please
    DeepBleu> tell me what is the difference between these two and what
    DeepBleu> libz.so is used for?

"zlib" is the name of a Python module.  "zlib.so" is the runtime incarnation
of that module.  My guess is that libz.so is a shared library version of the
C "zlib" library.  The Python module is essentially just a wrapper around
the zlib library.  On my linux machine ldd shows that zlib.so depends on
libz.so:

    % ldd zlib.so
            libz.so.1 => /lib/libz.so.1 (0x40015000)
            libgcc_s.so.1 => /usr/local/lib/libgcc_s.so.1 (0x40024000)
            libc.so.6 => /lib/libc.so.6 (0x4002c000)
            /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)

My guess is that you will see something similar on your Solaris system.

    DeepBleu> Also, I want to find out if zlib.so (the one that comes with
    DeepBleu> the Python distribution) is all we need to work with ZIP files
    DeepBleu> in Python. 

Technically, I suppose you could, but I think you'll find it a heck of a lot
easier to use the zipfile module (which uses zlib underneath the covers) to
work with ZIP files.

-- 
Skip Montanaro (skip at pobox.com - http://www.mojam.com/)