National Astronomical Observatory of Japan
Astronomy Data Center (ADC)
The Multi-Wavelength Data Analysis System (MDAS)
Group ID (GID) User's Guide

This page briefly describes how to use the group ID (GID) of the multi-wavelength data analysis system.

[Purpose of group-ID use]

Users who belong to the same group (GID) can work with collaborators by sharing data (files).

1. The default current group is the "adcusers" group when you logged in the analysis system.
   If you would like to change the current group to another group, you can use "newgrp" command.
   
   [Example]
   newgrp <GROUPNAME>
   
   (Note)
   
   • The change by "newgrp" command is valid on the terminal where the command was executed. When you opened a new terminal(shell), you need to execute "newgrp" command again to change the current group.
   • The 'newgrp' command starts a new shell. If you set the 'newgrp' command in the setup file for the shell (such as .bashrc), it may cause an endless loop.


2. Default permission is 660(770) when you create a new file (directory) with a sub GID.
   On the other hand, when you create a new file (directory) with the "adcusers" user group, the permission is 644(755).
   


3. If you would like to confirm your current group, you can use "id" command.
   Note that if you enter "id username", the registered information of the system is displayed (it is not the current state).
   


4. If you would like to change a group attribute of a file (directory), use "chgrp" command.