Updating database of manual pages
This option is followed by one or more packages desired for installation.
Each package is a package name, not a fully qualified filename (for instance, in a Fedora Core system, glibc would be the argument provided, not glibc-2.4.8.i686.rpm). The /etc/apt/sources.list(5) file is used to locate the repositories for the desired packages.
This allows a cache to be maintained over a long period of time without it growing out of control.
The configuration option APT:: Clean-Installed will prevent installed packages from being erased if it is set to off.
options can be used to search the manual page descriptions for instances of a given keyword.
For boolean options you can override the config file by using something like -f-, --no-f, -f=no or several other variations. Attempt to correct a system with broken dependencies in place.
Like clean, autoclean clears out the local repository of retrieved package files.
The difference is that it only removes package files that can no longer be downloaded, and are largely useless.
This will cause that version to be located and selected for install. " or "*" then it is assumed to be a POSIX regular expression, and it is applied to all package names in the database. Note that matching is done by substring so "lo.*" matches "how-lo" and "lowest".
Alternatively, a specific distribution can be selected by following the package name with a slash (/) and the version of the distribution or the Archive name (i.e. If this is undesired, anchor the regular expression with a "^" or "$" character, or create a more specific regular expression.