| Searching for strings | ||
|---|---|---|
 | Search patterns |  |
| Searching for strings | ||
|---|---|---|
| | Search patterns | |
Many search terms take a string as a parameter and match it against one or
more fields of a package. Strings can be entered either with or without
double quotes (「"」), so
「?name(scorch)?name("scorch")\」) immediately before it: for instance,
「?description("\"easy\"")"easy"」.
If you enter a 「bare」 string, one not surrounded by double
quotes, then aptitude will consider the string to have
「ended」 when it encounters the closing parenthesis or the comma
before a second argument to the search term. [14] To remove the special meaning of these characters, place a tilde
(「~」) directly before them. For instance,
「?description(etc)))」 ends the
?description term, and the second 「)」 does
not correspond to any 「(」. In contrast,
「?description(etc~))etc)」.
There are additional considerations if you are using the shorthand notation
for a term; see 「Shorthand for search terms」 for details.
Most textual searches (for package names, descriptions, etc) are performed
using case-insensitive regular
expressions. A regular expression will match against a field if any
portion of the field matches the expression; for instance,
「ogg[0-9]」 will match
「libogg5」,
「ogg123」, and
「theogg4u」. Some characters have a special
meaning within regular expressions [15] ,
so if you want to match them in searches you need to backslash-escape them:
for instance, to find 「g++」, you should use
the pattern 「g\+\+」.
The characters 「!」 and
「|」 have special meanings within search
patterns. In order to include these characters in an unquoted string, you
can place a tilde (「~」) directly before
them. For instance, to match packages whose description contains either
「grand」 or 「oblique」, use the pattern
「?description(grand~|oblique)?description("grand|oblique")
[14]
aptitude will only treat the comma as special if there is a second
argument, so (for instance)
「?name(apt,itude)apt,itude」 in the Name
field of packages.
While this behavior is well-defined, it may be surprising; I recommend using quoted strings for any pattern that contains characters that could have a special meaning.
[15]
Characters with a special meaning include:
「+」, 「-」,
「.」, 「(」,
「)」, 「|」,
「[」, 「]」,
「^」, 「$」,
and 「?」. Note that some of these are also
aptitude metacharacters, so if you want to type (for instance) a literal
「|」, it must be double-escaped:
「?description(\~|)|」).
| |  | |
| Search patterns |  | Shorthand for search terms |