On Tue, 2008-03-11 at 18:20 -0400, Eric B. wrote:
In my struggle today to get python2.4 installed on my CentOS4 system, I saw that it installed a packaged called alternatives which is supposed to handle symbolic links to default commands in a nice clean, structured way. However, I am having trouble understanding how this thing works.
I have read the man page half a dozen times already, and yet the alternative link for python which was installed doesn't seem to follow what is written in the man page. I am trying to modify the default behaviour for it, but having a lot of difficulty.
As an end-user, the only important commands you need are:
"alternatives --display <name>": Show information about an alternative "alternatives --config <name>": Allow selection of an alternative "ls /var/lib/alternatives": Show valid alternatives
That's what I thought too, however, if I look in my /usr/bin directory I see the following: # ls -l /usr/bin/pyt* lrwxrwxrwx 1 root root 18 Mar 11 17:43 /usr/bin/python -> /etc/alternatives/links/|usr|bin|python lrwxrwxrwx 1 root root 40 Mar 11 17:31 /usr/bin/python2 -> /etc/alternatives/links/|usr|bin|python2 -rwxr-xr-x 2 root root 5396 Dec 11 05:30 /usr/bin/python2.3 -rwxr-xr-x 1 root root 3268 Sep 28 2005 /usr/bin/python2.4
but # alternatives --display python
returns nothing. If I look in /var/lib/alternatives, I only find "print", "mta" and "etags".
So I'm not quite sure how to update / modify the python alternative to point to another location instead. If I look in /etc/alternatives/links I see the following: # ls -l /etc/alternatives/links/ total 12 lrwxrwxrwx 1 root root 18 Mar 11 17:31 |usr|bin|python -> /usr/bin/python2.4 lrwxrwxrwx 1 root root 15 Mar 11 17:31 |usr|bin|python2 -> /usr/bin/python lrwxrwxrwx 1 root root 34 Mar 11 17:31 |usr|share|man|man1|python.1.gz -> /usr/share/man/man1/python2.4.1.gz
The rpm installer automatically created these links when I yum installed python24 from pyvault. (It automatically installed the alternatives pkg).
Thanks for the help!
Eric