Instead, it is a symbolic link to a name in the alternatives directory, which in turn is a symbolic link to the actual file referenced. The generic name is not a direct symbolic link to the selected alternative. The system administrator can override this and cause it to refer to /usr/bin/ed instead, and the alternatives system will not alter this setting until explicitly requested to do so. For example, if the text editors ed(1) and nvi(1) are both installed on the system, the alternatives system will cause the generic name /usr/bin/editor to refer to /usr/bin/nvi by default. The alternatives system and the system administrator together determine which actual file is referenced by this generic name. A generic name in the filesystem is shared by all files providing interchangeable functionality. This gives choice to the users of a system, allowing each to use a different editor, if desired, but makes it difficult for a program to make a good choice for an editor to invoke if the user has not specified a particular preference.ĭebian's alternatives system aims to solve this problem.

For example, many systems have several text editors installed at once. It is possible for several programs fulfilling the same or similar functions to be installed on a single system at the same time. Update-alternatives creates, removes, maintains and displays information about the symbolic links comprising the Debian alternatives system.

Update alternatives java