for the X Window System. Some options are only implemented in
.BR apt-get (8)
though.
-.SH OPTIONS
-None.
-.SH FILES
-None.
.SH SEE ALSO
.BR apt-cache (8),
.BR apt-get (8),
.BR apt.conf (5),
.BR sources.list (5),
+.BR apt_preferences (5),
.BR apt-secure (8)
.SH DIAGNOSTICS
apt returns zero on normal operation, decimal 100 on error.