The update-alternatives
class helps the
alternatives system when multiple sources provide the same command.
This situation occurs when several programs that have the same or
similar function are installed with the same name.
For example, the ar
command is available from the
busybox
, binutils
and
elfutils
packages.
The update-alternatives
class handles
renaming the binaries so that multiple packages can be installed
without conflicts.
The ar
command still works regardless of which
packages are installed or subsequently removed.
The class renames the conflicting binary in each package and symlinks
the highest priority binary during installation or removal of packages.
To use this class, you need to define a number of variables:
These variables list alternative commands needed by a package,
provide pathnames for links, default links for targets, and
so forth.
For details on how to use this class, see the comments in the
update-alternatives.bbclass
.
update-alternatives
command
directly in your recipes.
However, this class simplifies things in most cases.