Once you have installed urpkg, you cannot install a program with it right away. If you try, you will find that files can only be written where everybody has write permission. Concretely, the package foo cannot be installed in allowed or in restricted at the moment. Let's make sure of this.

  $ sudo urpkg --install install -v foo1 ../restricted/.

Should output something like this

  Installing package foo-20080527...
  Preinstall script
  Running install command: install -v foo1 ../restricted/.
  install: cannot create regular file `../restricted/./foo1': Permission denied
  `foo1' -> `../allowed/./foo1'
  *** WARNING: The install command printed something to stderr (see /var/tmp/install.log): 
  install: cannot create regular file `../restricted/./foo1': Permission denied
  *** ERROR ***
  urpkg: Command install with arguments '-v foo1 ../restricted/.' returned non-zero status 1
  Cleaning up...
  Terminating all processes...
  Closing all files...
  Uninstalling uncompletely installed package. PLEASE DO NOT KILL
  Uninstalling package foo-20080527...
  Listing and removing files...
  Removing package user...

What happened was that our package user had no permission to write in ../restricted, so the installation command failed and the program was immediately uninstalled.

To allow programs to be installed in a directory, you need to change the directory's permissions.

Before doing that, you have to create two special groups. They are described in more details in the section called “Package user groups”

  $ sudo groupadd urpkgrp-install
  $ sudo groupadd urpkgrp-shared

Now you can invoke the gen command on the directories in which you want to allow packages to be installed.

  $ sudo urpkg --gen ../allowed

This allows any package user to write in ../allowed. However, existing files in these directories cannot be overwritten or removed by anything else than the package those files belong to. As an example

  $ sudo urpkg --install install -v file2 ../allowed/file2

Will not work. You might simply want to remove ../allowed/file2 and then retry, but what if the installation script needs the content of file2 ? For example, file2 could be an index, and the installation script might just want to append something to the index. The solution to this is to change the permission of file2 to allow it to be overwritten. It will still not be possible to remove it though. This is done using the share command.

  $ sudo urpkg --share ../allowed/file2

Directories where one can install program are referred to as installation directories while regular files that package user can overwrite are called shared files. In a real system, installation directories would for example be /usr/bin/ or /etc. Shared files are rarer but can for example include /usr/share/info/dir, the index of all installed info documentation files.

To make a shared file a normal file, or make an install directory a usual directory, use respectively --unshare and --ungen. If you want to list your shared files, use --list-shared, --list-instdir is used to list installation directories.