1This is versioncheck 1.0, a first stab at automatic checking of versions of 2Python extension packages installed on your system. 3 4The basic idea is that each package contains a _checkversion.py 5somewhere, probably at the root level of the package. In addition, each 6package maintainer makes a file available on the net, through ftp or 7http, which contains the version number of the most recent distribution 8and some readable text explaining the differences with previous 9versions, where to download the package, etc. 10 11The checkversions.py script walks through the installed Python tree (or 12through a tree of choice), and runs each _checkversion.py script. These 13scripts retrieve the current-version file over the net, compares version 14numbers and tells the user about new versions of packages available. 15 16A boilerplate for the _checkversion.py file can be found here. Replace 17package name, version and the URL of the version-check file and put it in 18your distribution. In stead of a single URL you can also specify a list 19of URLs. Each of these will be checked in order until one is available, 20this is handy for distributions that live in multiple places. Put the 21primary distribution site (the most up-to-date site) before others. 22The script is executed with execfile(), not imported, and the current 23directory is the checkversion directory, so be careful with globals, 24importing, etc. 25 26The version-check file consists of an rfc822-style header followed by 27plaintext. The only header field checked currently is 28'Current-Version:', which should contain te current version and is 29matched against the string contained in the _checkversion.py script. 30The rest of the file is human-readable text and presented to the user if 31there is a version mismatch. It should contain at the very least a URL 32of either the current distribution or a webpage describing it. 33 34Pycheckversion.py is the module that does the actual checking of versions. 35It should be fine where it is, it is imported by checkversion before anything 36else is done, but if imports fail you may want to move it to somewhere 37along sys.path. 38 39 Jack Jansen, CWI, 23-Dec-97. 40 <jack@cwi.nl> 41 42