1 This is versioncheck 1.0, a first stab at automatic checking of versions of

     2 Python extension packages installed on your system.

     3 

     4 The basic idea is that each package contains a _checkversion.py

     5 somewhere, probably at the root level of the package. In addition, each

     6 package maintainer makes a file available on the net, through ftp or

     7 http, which contains the version number of the most recent distribution

     8 and some readable text explaining the differences with previous

     9 versions, where to download the package, etc.

    10 

    11 The checkversions.py script walks through the installed Python tree (or

    12 through a tree of choice), and runs each _checkversion.py script. These

    13 scripts retrieve the current-version file over the net, compares version

    14 numbers and tells the user about new versions of packages available.

    15 

    16 A boilerplate for the _checkversion.py file can be found here. Replace

    17 package name, version and the URL of the version-check file and put it in

    18 your distribution. In stead of a single URL you can also specify a list

    19 of URLs. Each of these will be checked in order until one is available,

    20 this is handy for distributions that live in multiple places. Put the

    21 primary distribution site (the most up-to-date site) before others.

    22 The script is executed with execfile(), not imported, and the current

    23 directory is the checkversion directory, so be careful with globals,

    24 importing, etc.

    25 

    26 The version-check file consists of an rfc822-style header followed by

    27 plaintext. The only header field checked currently is

    28 'Current-Version:', which should contain te current version and is

    29 matched against the string contained in the _checkversion.py script.

    30 The rest of the file is human-readable text and presented to the user if

    31 there is a version mismatch. It should contain at the very least a URL

    32 of either the current distribution or a webpage describing it.

    33 

    34 Pycheckversion.py is the module that does the actual checking of versions.

    35 It should be fine where it is, it is imported by checkversion before anything

    36 else is done, but if imports fail you may want to move it to somewhere

    37 along sys.path.

    38 

    39 	Jack Jansen, CWI, 23-Dec-97.

    40 	<jack@cwi.nl>

    41