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The `uco -home' Command

  Arnaud Taddei CN/DCI

In the last CNL issue, we presented an article about the uco command which is a user reset command. It helps users who have afs accounts (the recommended file system to use the central services such as cernsp, hpplus or the Work Group Servers) to reset several files and directories which are used to configure their environment.

In the previous article we showed how to get the default HEPIX X11 environment. Now we describe how to update the Home directory structure.

There are several reasons why you may need to update the structure of your Home directory:

• You have an old account and several features have changed in the meantime: you want to update the file layout of your home directory to be compliant with the latest recommendations.
• You removed a directory by mistake and you were not aware of the consequences: you want to go back to the recommended structure with all permissions set up correctly.
• There is a new version of an operating system and the directory or link for it has to be created.
• Other cases or circumstances not listed here.

As an example, in the last few months several new versions of operating systems have been introduced: Solaris 2.4, AIX 4.1, OSF1 3.2C.

On afs, when you want to access an executable file, you have to put it into a directory named $HOME/bin which is a link to $HOME/.@sys/bin where @sys represents the reference to the current operating system name (in the afs naming scheme). If you list the files and directories of your $HOME, you will find many things and amongst them, you might have directories like:

.rs_aix32
.sun4m_53
.alpha_osf1

or links like:

.sun4m_52 -> .sun4m_53
.rs_aix41 -> .rs_aix32

Then, assuming you are working on an AIX 3.2 machine and you want to access one of your programs that you compiled for this architecture, you put this program under $HOME/rs_aix32/bin and you just need to issue the command name to run it. Indeed the HEPiX $PATH variable includes the segment: $HOME/bin which is a link to $HOME/.@sys/bin which refers to $HOME/rs_aix32/bin. Now, if you connect to an AIX 4.1 machine (and you know that the program compiled on AIX 3.2 should work on this new version), you should create a link .rs_aix32 in your $HOME directory. Without it you cannot access your command. For this You need to issue the uco -home command to update the structure of your Home directory by entering:

 uco -home

It will display:

 Home's possible actions:
   0 - Cancel.
   1 - Reset the structure of your 
       HOME directory.
 Choice:

Choose 1 and several new directories and links will appear.

If you need more information contact:

setup.support@cern.ch.