Selects documents that contain matches to a wildcard character string.
The WILDCARD operator lets you define a wildcard string,
which can be used to locate related word matches in documents. A wildcard
string consists of special characters.
For example, to retrieve documents that contain words such as "pharmaceutical", "pharmacology", and "pharmacodynamics" you can enter the following:
pharmac*
Documents are not relevance-ranked unless the MANY modifier is used, as in:
<MANY> pharmac*
The wildcard characters "*" and "?" automatically enable wildcard
searching. To use other constructs, use the WILDCARD
operator explicitly with any of the characters below.
| Character | Function |
|---|---|
? |
Specifies one of any alphanumeric character, as in
?an, which locates "ran", "pan", "can", and "ban". It
is not necessary to specify the WILDCARD operator if
you use the question mark. The question mark is ignored in a set
([ ]) or in an alternative pattern
({ }). |
* |
Specifies zero or more of any alphanumeric character,
as in corp*, which locates "corporate",
"corporation", "corporal", and "corpulent". It is not necessary to
specify the WILDCARD operator when you use the
asterisk; you should not use the asterisk to specify the first
character of a wildcard string. The asterisk is ignored in a set
([ ] ) or in an alternative pattern
({ } ). |
[ ] |
Specifies one of any character in a set, as in
<WILDCARD> 'c[auo]t', which locates "cat",
"cut", and "cot". You must enclose the word that includes a set in
backquotes, and there can be no spaces in a set. |
{ } |
Specifies one of each pattern separated by a comma, as in<WILDCARD> 'bank{s,er,ing}', which
locates "banks", "banker", and "banking". You must enclose the
word that includes a pattern in backquotes, and there can be no
spaces in a set. |
^ |
Specifies one of any character not in the set, as in
<WILDCARD> 'st[^oa]ck', which excludes "stock"
and "stack" but locates "stick" and "stuck". The caret
(^) must be the first character after the left
bracket ([) that introduces a set. |
- |
Specifies a range of characters in a set, as in
<WILDCARD> 'c[a-r]t', which locates every
three-letter word from "cat" to "crt". |
Searching for Non-Alphanumeric Characters
Remember that you can search for non-alphanumeric characters only if
the style.lex file used to create the collections you are
searching is set up to recognize the characters you want to search for.
Please consult your collection administrator for more information.
Searching for Wildcard Characters as Literals
Provided the style.lex file is set up for the collections
to be searched, you can search for a word containing a wildcard character
such as "/" or "*" by preceding the wildcard character with a backslash.
For example, if you enter the following search string:
abc\*d
the engine finds five-character words matching the "abc*d” string. When you want to match a literal backslash, enter two backslashes.
Searching for Special Characters as Literals
The following non-alphanumeric characters perform special, internal search engine functions, and by default are not treated as literals in a wildcard string:
To interpret special characters as literals, the whole wildcard string needs to be enclosed in backquotes. For example, to search for the wildcard string "a{b", you enclose the string with backquotes, as follows:
<WILDCARD> `a{b`
To search for a wildcard string that includes the literal backquote character, you need to use two backquotes together and enclose the whole wildcard string with backquotes, as follows:
<WILDCARD> `*n``t`
You can search for backquotes only if the style.lex file
used to create the collections you are searching is set up to recognize
the backquote character.