When you search for a package or set a display limit in aptitude, the string you enter is known as a “search pattern”. While the most basic usage of search patterns is to match packages by name, aptitude allows you to create much more complex searches. In addition to the visual interface, some command-line operations can use search terms; see Command-Line Reference for details.
A search pattern consists of one or more conditions (sometimes
known as “terms”); packages match the pattern if
they match all of its terms. Terms generally start with a
question mark (“?”), followed by the name of the
match term, which describes the search that the term performs:
for instance, the term
?name matches package names, while
?version matches package versions. Finally, any
additional parameters to the search term are placed in
parentheses (see the documentation of individual terms for
more information on this).