Help:CirrusSearch/zh

The quickest way to find information in Wikimedia projects is to look it up directly. On every page there is a  box.

CirrusSearch是一个使用Elasticsearch，来提高默认MediaWiki搜索功能MediaWiki扩展. 维基媒体基金会已在所有维基媒体项目上使用了CirrusSearch. 此页面叙述CirrusSearch的功能. 如果你的疑问并未得到解答，请在讨论页提问，热心用户将会为你解答.

更多有关MediaWiki扩展的信息，请参见Extension:CirrusSearch.

工作原理
Enter key words and phrases and press Enter or Return on your keyboard. Or click the magnifying glass icon, Search, or Go button. If a page has the same title as what you entered (or you use the Go button) you will be directed to that page. Otherwise, it searches all pages on the wiki, and presents a list of articles that matched your search terms, or a message informing you that no page has all the key words and phrases.

If you click the "" button without filling in anything, you will be taken to "Special:Search" which gives you extra searching options (also available from any search results list)

You may find it useful to restrict a search to pages within a particular namespace e.g., only search within the     pages. Check the namespaces you require for this search.

By default only the namespaces specified in your preferences will be searched. Logged-in users can change their preferences to specify the namespaces they want to search by default. This can be done by selecting and deselecting boxes in the ”search” section of user preferences.

作了哪些改进？
CirrusSearch较之于默认的MediaWiki搜索三大改进，主要有：


 * 更好的支持以不同语言搜索.
 * 更快的更新搜索索引，即页面修改能更快在搜索引擎中显示出来.
 * 展开模板，即在一個模板中的全部内容也能被搜索引擎搜索到.

搜索索引的更新频率如何？
搜索结果的索引列表会被及时更新. 你可以在改变输入内容时立即得到搜索结果. 对模板的变更将会在数分钟内对包含其的条目起作用. 由于采用任务调度模式来处理这些变更，所以实际情况可能略有不同. 对文章的编辑进行空编辑，也会强制系统进行刷新——所以正常情况下不要进行这样的操作.

搜索建议
当你在搜索框中键入关键字时，下拉框提供的搜索建议的排列顺序与各词条所拥有的导入链接数有关. This takes into account the number of incoming wikilinks, the size of the page, the number of external links, the number of headings, and the number of redirects. 如果你在关键词前加入“～”，将不会匹配任何词条. 同时，你可以随时按回车键进入搜索结果页. ASCII/accents/diacritics folding is turned on for English text, but there are some formatting problems with the result. See.

全文搜索
全文搜索功能（类似“在结果页中查找”）会搜索网页标题、重定向链接、小标题以及正文，所以搜索结果相对稳定. 本次主要的改动在于模板的扩充. There are many indexes of the "full text" of the wiki to facilitate the many types of searches needed. The full wikitext is indexed many times into many special-purpose indexes, each parsing the wikitext in whatever way optimizes their use. Example indexes include: There is support for dozens of languages, but all languages are wanted. There is a list of currently supported languages at elasticsearch.org; see their documentation on contributing to submit requests or patches. CirrusSearch will optimize your query, and run it. The resulting titles are weighted by relevance, and heavily post-processed, 20 at a time, for the search results page. For example snippets are garnered from the article, and search terms are highlighted in bold text.
 * "auxiliary" text, includes hatnotes, captions, ToC, and any wikitext classed by an HTML attribute class=searchaux.
 * "Lead-in" text is the wikitext between the top of the page and the first heading.
 * The "category" text indexes the listings at the bottom.
 * Templates are indexed. If the transcluded words of a template change, then all the pages that transclude it are updated. (This can take a long time depending on a job queue.) If the subtemplates used by a template change, the index is updated.
 * Document contents that are stored in the File/Media namespace are now indexed. Thousands of formats are recognized.

Search results will often be accompanied by various preliminary reports. These include Did you mean (spelling correction), and, when no results would otherwise be found it will say Showing results for (query correction) and search instead for (your query).

Search features also include:


 * sorting navigation suggestions by the number of incoming links.
 * Starting with the tilde character  to disable navigation and suggestions in such a way that also preserves page ranking.
 * Smart-matching characters by normalizing (or "folding") non-keyboard characters into keyboard characters.* Words and phrases that match are highlighted in bold on the search results page. The highlighter is a cosmetic analyzer, while the search-indexing analyzer actually finds the page, and these may not be 100% in sync, especially for regex. The highlighter can match more or less accurately than the indexer.

字词与修改
The basic search term is a word or a "phrase in quotes". Search recognizes a "word" to be:


 * a string of digits
 * a string of letters
 * subwords between letters/digit transitions, such as in txt2regex
 * subwords inside a compoundName using camelCase

A "stop word" is a word that is ignored (because it is common, or for other reasons). A given search term matches against content (rendered on the page). To match against wikitext instead, use the insource search parameter (See section below). Each search parameter has its own index, and interpret its given term in its own way.

Spacing between words, phrases, parameters, and input to parameters, can include generous instances of whitespace and greyspace characters. "Greyspace characters" are all the non-alphanumeric characters ~!@#$%^&*_+-={}|[]\:";'<>?,./ . A mixed string of greyspace characters and whitespace characters, is "greyspace", and is treated as one big word boundary. Greyspace is how indexes are made and queries are interpreted.

Two exceptions are where 1) an embedded:colon is one word (it being treated as a letter), and 2) an embedded comma, such as in 1,2,3, is treated as a number. Greyspace characters are otherwise ignored unless, due to query syntax, they can be interpreted as modifier characters.

The modifiers are ~ * \? - " ! . Depending on their placement in the syntax they can apply to a term, a parameter, or to an entire query. Word and phrase modifiers are the wildcard, proximity, and fuzzy searches. Each parameter can have their own modifiers, but in general:


 * A fuzzy-word or fuzzy-phrase search can suffix a tilde  character (and a number telling the degree).
 * A tilde  character prefixed to the first term of a query guarantees search results instead of any possible navigation.
 * A wildcard character inside a word can be a (escaped) question \? mark for one character or an asterisk * character for more.
 * Truth-logic can interpret AND and OR, but parameters cannot.
 * Truth-logic understands - or ! prefixed to a term to invert the usual meaning of the term from "match" to "exclude".
 * Quotes around words mark an "exact phrase" search. For parameters they are also needed to delimit multi-word input.
 * Stemming is automatic but can be turned off using an "exact phrase".

A phrase search can be initiated by various hints to the search engine. Each method of hinting has a side-effect of how tolerant the matching of the word sequence will be. For greyspace, camelCase, or txt2number hints: A "search instead" report is triggered when a universally unknown word is ignored in a phrase.
 * given words-joined_by_greyspace(characters) or wordsJoinedByCamelCaseCharacters it finds words joined by ... characters, in their bare forms or greyspace forms.
 * txt2number will match  or.
 * Stop words are enabled for the edge cases (in the periphery) of a grey_space or camelCase phrase. An example using the, of , and a is that the_invisible_hand_of_a matches.

Each one of the following types of phrase-matching contains and widens the match-tolerances of the previous one:
 * An "exact phrase" "in quotes" will tolerate (match with) greyspace. Given "exact_phrase" or "exact phrase" it matches.
 * A greyspace_phrase initiates stemming and stop word checks.
 * Given CamelCase it will additionally match, in all lowercase, because CirrusSearch is not case sensitive in matching.

Page ranking saves you from typing quotes for a two-word search. With no quotes a word-pair index is used in page-ranking, plus it finds the two words anywhere on the page.

Some parameters interpret greyspace phrases, but other parameters, like insource only interpret the usual "phrase in quotes".

Note that all stemming is case insensitive.

Note how the "exact phrase" search interpreted the embedded:colon character as a letter, but not the embedded_underscore character. A similar event occurs with the comma, character inside a number.

Given, CirrusSearch, when in an "exact phrase" context, (which includes the insource parameter context), will not match  ,  , or  , but will then only match.

Otherwise, remember that for CirrusSearch words are letters, numbers, or a combination of the two, and case does not matter.

The common word search employs the space character and is aggressive with stemming, and when the same words are joined by greyspace characters or camelCase they are aggressive with phrases and subwords.

When common words like "of" or "the" are included in a greyspace-phrase, they are ignored, so as to match more aggressively.

A greyspace_phrase search term, or a camelCase, or a txt2number term, match the signified words interchangeably. You can use any of those three forms. Now camelcase matches camelCase because Search is not case sensitive, but camelCase matches camelcase because camelCase is more aggressive. Like the rest of Search, subword "words" are not case-sensitive. By comparison the "exact phrase" is greyspace oriented and ignores numeric or letter-case transitions, and stemming. "Quoted phrases" are not case sensitive.

From the table we can surmise that the basic search parser_function -"parser function" is the sum of the basic searches  and.

Making inquiries with numbers, we would find that: The star * wildcard matches a string of letters and digits within a rendered word, but never the beginning character. One or more characters, a percentage of the word, must precede the * character. The \? wildcard represents one letter or number; The *\? is also accepted, but \?* is not recognized.
 * Plan9 or Plan_9 matches any of:,  ,  ,  ,
 * "plan9" only matches  (case insensitive)
 * Plan*9 matches  or.
 * If the leading part is only letters then it will limit a match to a string of (zero of more) letters.
 * If only numbers, then it will limit a match to a sequence of (zero or more) numbers, including also ordinal letters (st, nd, rd), capital letters, or time abbreviations (am or pm); and it will match the entirety of (both sides of) a decimal numbers.
 * Otherwise the comma is considered part of one number, but the decimal point is considered a greyspace character, and will delimit two numbers.
 * Inside an "exact phrase" it matches stemming plus compounding.

The wildcards are for basic word, phrase, and insource searches, and may also be an alternative to (some) advanced regex searches (covered later).

Putting a tilde ~ character after a word or phrase activates a fuzzy search.
 * For a phrase it is termed a proximity search, because proximal words are tolerated to an approximate rather than exact phrase.
 * For example, "exact one two phrase"~2 matches.
 * For a word it means extra characters or changed characters.
 * For a phrase a fuzzy search requires a whole number telling it how many extra words to fit in, but for a word a fuzzy search can have a decimal fraction, defaulting to word~0.5 ( word~.5 ), where at most two letters can be found swapped, changed, or added, but never the first two letters.
 * For a proximity phrase, a large number can be used, but that is an "expensive" (slow) search.
 * For a word word~.1 is most fuzzy, and word~.9 is least fuzzy, and word~1 is not fuzzy at all.

For the closeness value necessary to match in reverse (right to left) order, count and discard all the extra words, then add twice the total count of remaining words minus one. (In other words, add twice the number of segments). For the full proximity algorithm, see Elasticsearch slop. An explicit AND is required between two phrases because otherwise the two "inner" "quotation marks" are confused. 一些情况下，您还可以点击浏览器中的‘后退’按钮返回到链接媒体查看器中图像的页面.

源代码搜索
源代码搜索（Insource）功能可被用于查找任何在页面上渲染的“文字”，但它主要用于查找您可能很难找到词——包含MediaWiki标记. 这个搜索词完全忽略灰色空间： insource: "state state autocollapse" 匹配. Insource complements itself. On the one hand it has full text search for any word in the wikitext, instantly. On the other hand it can process a regexp search for any string of characters. Regex scan all the textual characters in a given list of pages; they don't have a word index to speed things up, and the process is interrupted if it must run more than twenty seconds. Regex run last, so to limit needless character-level scanning, you advance it a list of pages (a search domain) selected by an indexed search added to the query as a "clause", and you do this to every single regex query. . Insource can play both roles, and the best candidate for insource:/arg/ is often insource: arg, where arg is the same.

The syntax for the regexp is insource: no space, and then /regexp/. (No other parameter disallows a space. All the parameters except insource:/regexp/ generously accept space after their colon.)

Insource indexed-search and regexp-search roles are similar in many respects: But indexed searches all ignore greyspace; wildcards searches do not match greyspace, so regex are the only way to find an exact string of any characters, for example a sequence of two spaces. Regex are an entirely different class of search tool that make matching a literal string in a regexp exact string search, a basic, easy search. Advanced regex are an entirely different endeavor than matching a literal string. See below.
 * Both search wikitext only.
 * Neither finds things "sourced" by a transclusion.
 * Neither does stemmed, fuzzy, or proximity searches.
 * Both want the fewest results, and both work faster when accompanied by another clause.

前缀和名字空间
For Search, a namespace term functions to specify the initial search domain. Instead of searching the entire wiki, the default is the main namespace (mainspace).

Only one namespace name can be set from the search box query. It is either the first term or in the last term, in a prefix parameter.

Two or more namespaces may be searched from the Advanced pane of the search bar found on the top of every search results page, Special:Search. Your search domain, as a profile of namespaces, can be set here (without going to the user preferences page). The namespaces list will then present itself on the first page of future search results to indicate the search domain of the search results. To unset this, select the default namespace (shown in parentheses), select "Remember", and press Search.

The search bar graphically sets and indicates a search domain. "Content pages" (mainspace), "Multimedia" (File), "Everything" (all plus File), "Translations", etc., are hyperlinks that can activate the query in that domain, and then indicate this by going inactive (dark). But the query will override the search bar. When a namespace or prefix is used in the query the search bar activations and indications may be misleading, so the search bar and the search box are mutually exclusive (not complementary) ways to set the search domain.

A namespace term overrides the search bar, and a prefix term overrides a namespace.

Enter a namespace name, or enter, or enter a     colon for mainspace. All does not include the File namespace. File includes media content held at Commons such as PDF, which are all indexed and searchable. When File is involved, a namespace modifier  has an effect, otherwise it is ignored. 名字空间的别名也是被接受的. As with search parameters, local and all must be lowercase. Namespaces names are case insensitive.

The prefix: parameter matches any number of first-characters of all pagenames in one namespace. When the first letters match a namespace name and colon, the search domain changes. Given a namespace only, prefix will match all its pagenames. Given one character only, it cannot be - dash or ' quote or " double quote. The last character cannot be a colon. For pagenames that match, their subpage titles match by definition. The prefix parameter does not allow a space before a namespace, but allows whitespace before a pagename.

The prefix parameter goes at the end so that pagename characters may contain " quotation marks.

The Translate extension creates a sort of "language namespace", of translated versions of a page. But unlike namespace or prefix, which create the initial search domain, the inlanguage parameter is a filter of it. (See the next section.)

过滤器
A filter can have multiple instances, and negated instances, and it can run as a standalone filtering a search domain. A query is formed as terms that filter a search domain. A namespace or a prefix term is not a filter because a namespace will not run standalone, and a prefix will not negate.

Adding another word, phrase, or parameter filters more. A highly refined search result may have very many Y/N filters when every page in the results will be addressed. (In this case ranking is largely irrelevant.) Filtering applies critically to adding a regex term; you want as few pages as possible before adding a regex (because it can never have a prepared index for its search).

The search parameters below are filters. Insource (covered above) is also a filter, but insource:/regexp/ is not a filter. Filters and all other search parameters are lowercase. (Namespaces are an exception, being case insensitive.)

Intitle and incategory
Word and phrase searches match in a title and match in the category box on bottom of the page. But with these parameters you can select titles only or category only.

Intitle and incategory are old search parameters. Incategory no longer searches any subcategory automatically, but you can now add multiple category pagenames manually. To get the search parameter deepcat, to automatically add up to 70 subcategories onto an incategory parameter, incategory:category1|category2|...|category70 , you can add a line to your Custom JavaScript.
 * cow*
 * Find articles whose title or text contains words that start with cow
 * intitle:foo
 * 查找标题包含foo的条目. 词干提取对foo启用.
 * intitle:"fine line"
 * 查找标题同时包含foo和bar的条目. 词干提取对foo和bar启用.
 * intitle:foo bar
 * 查找标题包含foo或包含bar的条目.
 * -intitle:foo bar
 * 查找标题既不包含“foo”、也不包含“bar”的词条.
 * incategory:Music
 * 查找属于“Music”分类的词条
 * incategory:"music history"
 * 查找属于“Music_history”分类的词条
 * incategory:"musicals" incategory:"1920"
 * 查找同时属于“Musicals”和“1920”分类的词条
 * -incategory:"musicals" incategory:"1920"
 * 查找属于“1920”分类，但不属于“musicals”的词条

Linksto
Linksto finds wikilinks to a given name, not links to content. The input is the canonical, case sensitive, page name. It must match the title line of the content page, exactly, before any title modifications of the letter-case. (It must match its { {FULLPAGENAME}}, e.g. .)

Linksto does not find redirects. It only finds [ [wikilinks]], even when they are made by a template. It does not find a link made by a URL, even if that URL is an internal wiki link.

To find all wikilinks to a "Help:Cirrus Search", if "Help:Searching" and "H:S" are redirects to it:
 * 1) linksto: "Help:Cirrus Search"
 * 2) linksto: Help:Searching
 * 3) linksto: H:S

finds articles that mention "CirrusSearch" but not in a wikilink.

Hastemplate
You can specify template usage with. Input the canonical pagename to find all usage of the template, but use any of its redirect pagenames finds just that naming. Namespace aliases are accepted, capitalization is entirely ignored, and redirects are found, all in one name-search. (Compare boost-template no default namespace; linksto no namespace aliases, case-sensitive, no redirects; intitle no redirects.)

Hastemplate finds secondary (or meta-template) usage on a page: it searches the post-expansion inclusion. This is the same philosophy as for words and phrases from a template, but here it's for templates from a template. The page will be listed as having that content even though that content is not seen in the wikitext.


 * hastemplate: "quality image", finds "Template:Quality image" usage in your default search domain (namespaces).
 * : hastemplate: portal:contents/tocnavbar, finds mainspace usage of a "Contents/TOCnavbar" template in the Portal namespace.

For installations with the Translate extension, hastemplate searches get interference wherever Template:Translatable template name wraps the template name of a translatable template. Use insource instead.

Inlanguage
For installations with the Translate extension, inlanguage is important for highly refined searches and page counts.


 * inlanguage: 语言代码

will produce search results in that language only.

例如


 * to count all Japanese pages on the wiki
 * all: inlanguage: ja


 * to filter out German and Spanish pages in the Help namespace
 * help: -inlanguage: de -inlanguage: es


 * to ignore Translate, and where English is the base language, add
 * inlanguage:en

contentmodel
The contentmodel: keyword allows to limit the search to pages of specific content model. E.g.:


 * To see only JSON pages:
 * contentmodel:json

页面权重
Weighting determines snippet, suggestions, and page relevance. The normal weight is one. Additional weighting is given through multipliers.

If the query is just words, pages that match them in order are given a boost. If you add any explicit phrases to your search, or for certain other additions, this "prefer phrase" feature is not applied.

Morelike
The morelike: query works by choosing a set of words in the input articles and run a query with the chosen words. You can tune the way it works by adding the following parameters to the search results URL: These settings can be made persistent by overriding  in Special:MyLanguage/Help:System message.
 * morelike:page name 1|page name 2|...|page name n
 * 查找与给定文章的文本最接近类似的词条.
 * morelike:wasp|bee|ant
 * 查找有关昆虫叮咬的词条.
 * morelike:template:search|template:regex|template:usage
 * 查找在本wiki上在模板名字空間使用的有關regex的查找结果.
 * cirrusMltMinDocFreq : Minimum number of documents (per shard) that need a term for it to be considered.
 * cirrusMltMaxDocFreq : Maximum number of documents (per shard) that have a term for it to be considered.
 * cirrusMltMaxQueryTerms : Maximum number of terms to be considered.
 * cirrusMltMinTermFreq : Minimum number of times the term appears in the input to doc to be considered. For small fields ( title ) this value should be 1.
 * cirrusMltMinWordLength : Minimal length of a term to be considered. Defaults to 0.
 * cirrusMltMaxWordLength : The maximum word length above which words will be ignored. Defaults to unbounded (0).
 * cirrusMltFields (comma separated list of values): These are the fields to use. Allowed fields are title, text , auxiliary_text , opening_text , headings and all.
 * cirrusMltUseFields ( | ): use only the field data. Defaults to : the system will extract the content of the   field to build the query.
 * cirrusMltPercentTermsToMatch : The percentage of terms to match on. Defaults to 0.3 (30 percent).
 * Example:

Prefer-recent
Adding prefer-recent: anywhere in the query gives recently edited articles a slightly larger than normal boost in the page-ranking rules.

It defaults to boost only 60% of the score, in a large, 160 day window of time, which can be entered in the query as prefer-recent:0.6,160. This plays well with other page ranking rules, and is intended for most searches.

You can manipulate the rules: prefer-recent:boost,recent Technically "boost" is the proportion of score to scale, and "recent" is the half life in days. The boost is more than the usual multiplier, it is an exponential boost. The factor used in the exponent is the time since the last edit.

例如
 * prefer-recent:,7

Pages older than 7 days are boosted half as much, and pages older than 14 days are boosted half as much again, and so on.

For a simple "sort by date" in highly refined search results, where page ranking and boosting are largely meaningless, just boost the entire score:
 * prefer-recent:1,7 (weeks)
 * prefer-recent:1,1 (days)
 * prefer-recent:1,0.0007 (minutes)
 * prefer-recent:1,0.0001 (8.64 seconds)
 * prefer-recent:1,0.00001 (seconds)

Boost-templates
你可以根据所用模板不同来调整搜索结果的排列顺序，比如 ；或使用新语法 来设置默认选项（通过发送系统消息）. 会取代 的设置（如果后者已经被设置的话）. 这一语法很特别，但若使用得当则能简化搜索. 以下是一些例子：


 * File:boost-templates:"Template:Quality Image|200%" incategory:china
 * 查找中国分类下的文件，并将高质量的图片排列在最前.


 * File:boost-templates:"Template:Quality Image|200% Template:Low Quality|50%" incategory:china
 * 查找中国分类下的文件，并将高质量的图片排列在最前、低质量的图片排列在最后.


 * File:boost-templates:"Template:Quality Image|200% Template:Low Quality|50%" popcorn
 * Find files about popcorn sorting quality images first and low quality images last. Remember that through the use of the  message this can be reduced to just.

不要在表示比例的百分数中添加小数点. 这样做不会起作用，而且搜索结果也不会有很大差别.

使用警告：如果你在排序比例中设置了一个非常大或非常小的值，全文搜索将会受到影响. 比如，将词条排序比例设置为100,000,000%，那么系统将会优先匹配每个单词所对应的文章，而不是搜索语句本身所匹配的文章；同时，语法匹配功能也无法起作用. 结果，类似 的搜索将会匹配全文中包含“brave”、“new”、“world”三个词的词条，而不是词条Brave New World.

正则表达式搜索
A basic indexed-search finds words rendered visible on a page. Hyphenation and punctuation marks and bracketing, slash and other math and computing symbols, are merely boundaries for the words. It is not possible to include them in an indexed search.

These return much much faster when you limit the regexp search-domain to the results of one or more index-based searches.

Warning: Do not run a bare insource:/regexp/ search. It will probably timeout after 20 seconds anyway, while blocking responsible users.

An "exact string" regexp search is a basic search; it will simply "quote" the entire regexp, or "backslash-escape" all non-alphanumeric characters in the string. All regexp searches also require that the user develop a simple filter to generate the search domain for the regex engine to search:
 * insource:"debian.reproducible.net" insource: / debian\.reproducible\.net / 
 * insource:"c:\program files (x86)" insource: / C\:\\Program Files \(x86\) /i 
 * insource:"{ {template}}" insource: / "{ {template}}<\/tag>" /
 * insource:"[ [title|link label]]'s" insource: / "[ [title|link label]]'s" /
 * insource: / regexp / prefix:{ {FULLPAGENAME}}

The last example works from a link on a page, but { {FULLPAGENAME}} doesn't function in the search box.

For example: Special:Search/insource:/regex/ prefix: finds the term regex on this page.

A query with no namespace specified and no prefix specified searches your default search domain, (settable on any search-results page, i.e. at Special:Search). Some users keep their default search domain at "all namespaces", i.e. the entire wiki. On a large wiki if this user does a bare regexp search it will probably fail, incurring an HTML timeout, before completing the search.

A regex search actually scours each page in the search domain character-by character. By contrast, an indexed search actually queries a few records from a database separately maintained from the wiki database, and provides nearly instant results. So when using using an insource:// (a regexp of any kind), consider creating one the other search terms that will limit the regex search domain as much as possible. There are many search terms that use an index and so instantly provide a more refined search domain for the /regexp/. In order of general effectiveness: To test a bare regexp query you can create a page with test patterns, and then use the prefix parameter with that fullpagename. The match will be highlighted. It searches that page (in the database) and its subpages.
 * insource:"" with quotation marks, duplicating the regexp except without the slashes or escape characters, is ideal.
 * intitle, incategory, and linksto are excellent filters.
 * hastemplate: is a very good filter.
 * "word1 word2 word3", with or without the quotation marks, are good.
 * namespace: is practically useless, but may enable a slow regexp search to complete.

Search terms that do not increase the efficiency of a regexp search are the page-scoring operators: morelike, boost-template, and prefer-recent.

元字符
此节包含如何在rexexp搜索中，避免元字符（metacharacters）的内容 For the actual meaning of the metacharacters see the explanation of the syntax.

例如： Refining with an exact string. You can start out intending an exact string search, but keep in mind: There are two ways to escape metacharacters. They are both useful at times, and sometimes concatenated side-by-side in the escaping of a string. Double-quotes escaping using insource:/"regexp"/ is an easy way to search for many kinds of strings, but you can't backslash-escape anything inside a double-quoted escape. Backslash-escape using insource:/regexp/ allows escaping the " and / delimiters, but requires taking into account metacharacters, and escaping any: The simplest algorithm to create the basic string-finding expression using insource:/"regexp"/, need not take metacharacters into account except for the " and / characters:
 * to search a namespace, gauge the number of pages with a single term that is a namespace. This will list the number of pages in that namespace.
 * starting out to find again what you may have seen, like "wiki-link" or "(trans[in]clusion)" start with namespace and insource filters.
 * refinining an ongoing search process with what you want to see, like "2 + 2 = 4", or "site.org" This is ideally the best use of regex, because it adds it as a single regexp term while refining a search, the limited number of pages the regexp must crawl is can be seen.
 * regex only search the wikitext not the rendered text, so there are some differences around the markup, and even the number of space characters must match precisely.
 * You are obligated to supply an accompanying filter.
 * You must learn how to escape regex metacharacters.
 * Backslash-escape one of them \char. The insource:/regexp/ uses slashes to delimit the regexp. Giving /reg/exp/ is ambiguous, so you must write /reg\/exp/.
 * Put a string of them in double quotes "string". Because escaping a character can't hurt, you can escape any character along with any possible metacharacters in there. Escaping with quotes is cleaner.
 * You can't mix methods, but you can concatenate them.
 * instead of
 * is as good as
 * But  always.
 * And .  It finds the   literally, which is not the   you probably wanted.
 * To match a  delimiter character use.
 * To match a  delimiter character use.
 * The escaped metacharacters would be.
 * The equivalent expression escaped with double-quotes is.
 * 1) Write   out. (The /" delimiters "/ are not shown.)
 * 2) Replace   with   (previous double-quote: stop, concatenate, quote restart).
 * 3) Replace   with   (stop, concatenate, start).
 * 4) You get , showing concatenation of the two methods.

The square-bracket notation for creating your own character-class also escapes its metacharacters. To target a literal right square bracket in your character-class pattern, it must be backslash escaped, otherwise it can be interpreted as the closing delimiter of the character-class pattern definition. The first position of a character class will also escape the right square bracket. Inside the delimiting square brackets of a character class, the dash character also has special meaning (range) but it too can be included literally in the class the same way as the right square bracket can. For example both of these patterns target a character that is either a dash or a right square bracket or a dot:  or.

For general examples using metacharacters: There are some notable differences from standard regex metacharacters:
 * insource:"2+2=4" insource:/"2+2=4"/ matches "2 + 2 = 4", with zero spaces between the characters.
 * insource:"2 + 2 = 4" insource:/2 ?\+ ?2 ?= ?4\./ match with zero or one space in between. The equals = sign is not a metacharacter, but the plus + sign is.
 * insource:"[ [link|2\3?]]\" insource:/"[ [link|2\3?]]< "\/" tag>"/.
 * The dot . metacharacter stands for any character including a newline, so .* matches across lines.
 * The number # sign means something, and must be escaped.
 * The ^ and $ are not needed. Like "grep" (global per line, regular expression, print each line), each insource:// is a "global per document, regular expression, search-results-list each document" per document.
 * support a multi-digit numeric range like [0-9] does, but without regard to the number of character positions, or the range in each position, so <9-10> works, and even <1-111> works.

高级示例
For example, using metacharacters to find the usage of a template called Val having, inside the template call, an unnamed parameter containing a possibly signed, three to four digit number, possibly surrounded by space characters, AND on the same page, inside a template Val call, a named argument having any allowable spaces around it, (it could be the same template call, or a separate one):



Note that the = sign in "fmt commas" is not needed but that adding it would not change the search results. It is fast because it uses two filters so that every page the regexp crawls has the highest possible potential.

有界限
You can limit search to pages identified as being near some specified geographic coordinates. The coordinates can either be specified as a, pair, or by providing a page title from which to source the coordinates. A distance to limit the search to can be prepended if desired. 示例：


 * neartitle:"San Francisco"
 * neartitle:"100km,San Francisco"
 * nearcoord:37.77666667,-122.39
 * nearcoord:42km,37.77666667,-122.39

boosted
You can alternatively increase the score of pages within a specified geographic area. The syntax is the same as bounded search, but with boost- prepended to the keyword. This effectively doubles the score for pages within the search range, giving a better chance for nearby search results to be near the top.


 * boost-neartitle:"San Francisco"
 * boost-neartitle:"100km,San Francisco"
 * boost-nearcoord:37.77666667,-122.39
 * boost-nearcoord:42km,37.77666667,-122.39

文件属性搜索
Since MediaWiki 1.28, CirrusSearch supports indexing and searching of properties of files in the  namespace. This includes:
 * file media type
 * MIME type
 * size
 * width & height
 * resolution
 * bit depth for files that support these

文件类型
Searching for file type allows to retrieve files according to their classification, such as office documents, videos, raster images, vector images, etc. The following types currently exist:



This list may be extended in the future. See also  constants in.

The syntax of the search is: filetype:{type}. Example:

filetype:video - looks for all videos

The filetype search is not case-sensitive.

filemime
Matches file MIME type. The syntax is:

filemime:{MIMEtype} - look for files of this MIME type

The argument can be quoted to specify exact match. Without quotes, partial matches to components of MIME type will be accepted too.

示例：

filemime:"image/png" - look for files with MIME type exactly

filemime:pdf - look for all PDF documents

The MIME type search is not case sensitive.

filesize
Search for file of given size, in kilobytes (kilobyte means 1024 bytes). The syntax is:

filesize:{number} or filesize:>{number} - file with size at least given number

filesize:<{number} - file with size no more than given number

filesize:{number},{number} - file with size between given numbers

示例：

filesize:>20 or filesize:20 - files 20KB and bigger

filesize:<1024 ——小于1MB的文件

filesize:100,500 - files with sizes between 100KB and 500KB

File measures
It is possible to search for specific file measures: width, height, resolution (which is defined as square root of height × width), and bit depth. Not all files may have these properties. The syntax is:

{measure}:{number} - file with measure that equals to given number

{measure}:>{number} - file with measure that is at least given number

{measure}:<{number} - file with measure that is no more than given number

{measure}:{number},{number} - file with measure that is between given numbers

可以：

filew 或 filewidth ——文件宽度

fileh or fileheight - file height

fileres - file resolution (see above)

filebits - file bit depth

示例：

filew:>800 fileh:>600 - files that are at least 800x600 pixels in size

filebits:16 - files with 16-bit color depth

fileheight:100,500 - file between 100 and 500 pixels high

参见

 * Completion Suggester - the incremental search feature of CirrusSearch
 * See Search/Old for more on the development and debut of of CirrusSearch.
 * See Help:Searching for MWSearch, used by the many wikis that don't have a search extension.
 * See Help:Searching for MWSearch, used by the many wikis that don't have a search extension.

外部链接

 * From Lucene, highly relevant documentation.