Search Filter Syntax

Search filters enable you to define search criteria and provide more efficient and effective searches.

ADSI supports the LDAP search filters as defined in RFC2254. These search filters are represented by Unicode strings. The following table lists some examples of LDAP search filters.

Search filter	Description
«(objectClass=*)»	All objects.
«(&(objectCategory=person)(objectClass=user)(!(cn=andy)))»	All user objects but «andy».
«(sn=sm*)»	All objects with a surname that starts with «sm».
«(&(objectCategory=person)(objectClass=contact)(|(sn=Smith)(sn=Johnson)))»	All contacts with a surname equal to «Smith» or «Johnson».

These search filters use one of the following formats.

The ADSI search filters are used in two ways. They form a part of the LDAP dialect for submitting queries through the OLE DB provider. They are also used with the IDirectorySearch interface.

Operators

The following table lists frequently used search filter operators.

=

Logical operator	Description
=	Equal to
Approximately equal to
=	Lexicographically greater than or equal to
&	AND
|	OR
!	NOT

In addition to the operators above, LDAP defines two matching rule object identifiers (OIDs) that can be used to perform bitwise comparisons of numeric values. Matching rules have the following syntax.

The following table lists the matching rule OIDs implemented by LDAP.

Matching rule OID	String identifier (from Ntldap.h)	Description
1.2.840.113556.1.4.803	LDAP_MATCHING_RULE_BIT_AND	A match is found only if all bits from the attribute match the value. This rule is equivalent to a bitwise AND operator.
1.2.840.113556.1.4.804	LDAP_MATCHING_RULE_BIT_OR	A match is found if any bits from the attribute match the value. This rule is equivalent to a bitwise OR operator.
1.2.840.113556.1.4.1941	LDAP_MATCHING_RULE_IN_CHAIN	This rule is limited to filters that apply to the DN. This is a special «extended» match operator that walks the chain of ancestry in objects all the way to the root until it finds a match.

The following example query string searches for group objects that have the ADS_GROUP_TYPE_SECURITY_ENABLED flag set. Be aware that the decimal value of ADS_GROUP_TYPE_SECURITY_ENABLED (0x80000000 = 2147483648) is used for the comparison value.

The LDAP_MATCHING_RULE_IN_CHAIN is a matching rule OID that is designed to provide a method to look up the ancestry of an object. Many applications using AD and AD LDS usually work with hierarchical data, which is ordered by parent-child relationships. Previously, applications performed transitive group expansion to figure out group membership, which used too much network bandwidth; applications needed to make multiple roundtrips to figure out if an object fell «in the chain» if a link is traversed through to the end.

An example of such a query is one designed to check if a user «user1» is a member of group «group1». You would set the base to the user DN (cn=user1, cn=users, dc=x) and the scope to base , and use the following query.

Similarly, to find all the groups that «user1» is a member of, set the base to the groups container DN; for example (OU=groupsOU, dc=x) and the scope to subtree , and use the following filter.

Note that when using LDAP_MATCHING_RULE_IN_CHAIN, scope is not limited—it can be base , one-level , or subtree . Some such queries on subtrees may be more processor intensive, such as chasing links with a high fan-out; that is, listing all the groups that a user is a member of. Inefficient searches will log appropriate event log messages, as with any other type of query.

Wildcards

You can also add wildcards and conditions to an LDAP search filter. The following examples show substrings that can be used to search the directory.

Get all entries:

Get entries containing «bob» somewhere in the common name:

Get entries with a common name greater than or equal to «bob»:

Get all users with an email attribute:

Get all user entries with an email attribute and a surname equal to «smith»:

Get all user entries with a common name that starts with «andy», «steve», or «margaret»:

Get all entries without an email attribute:

The formal definition of the search filter is as follows (from RFC 2254):

If a must contain the asterisk (*), left parenthesis ((), or right parenthesis ()) character, the character should be preceded by the backslash escape character (\).

Special Characters

If any of the following special characters must appear in the search filter as literals, they must be replaced by the listed escape sequence.

ASCII character	Escape sequence substitute
*	\2a
(	\28
)	\29
\	\5c
NUL	\00
/	\2f

In cases where a MultiByte Character Set is being used, the escape sequences listed above must be used if the search is performed by ADO with the SQL dialect.

In addition, arbitrary binary data may be represented by using the escape sequence syntax by encoding each byte of binary data with the backslash (\) followed by two hexadecimal digits. For example, the four-byte value 0x00000004 is encoded as \00\00\00\04 in a filter string.

Microsoft Windows Search Filter Host — что это и почему грузит процессор? (SearchFilterHost.exe)

Microsoft Windows Search Filter Host или SearchFilterHost.exe — системный процесс отвечающий за работу локального поиска используя службу индексации файлов.

Больше нормальной информации нет. В принципе верно — да, процесс Microsoft Windows Search Filter Host и правда относится к поиску файлов.. к индексированию.. но дело в том, что еще есть процесс SearchIndexer.exe, он видимо нужен уже именно для самого индексирования. А SearchFilterHost.exe — возможно отвечает именно за поиск. Хотелось узнать разницу, однако в интернете увы — инфы нет.

Стандартное расположение файла SearchFilterHost.exe (Microsoft Windows Search Filter Host):

Microsoft Windows Search Filter Host грузит процессор — почему и что делать?

Некоторые причины и варианты решения:

1. Иногда, на некоторых ПК процесс грузит потому что банально индексирует все файлы. Каким-то образом раньше процесс не смог проиндексировать все файлы, и ему нужно время, чтобы провести индексацию именно всех файлов. После — он будет уже индексировать только новые, поэтому нагрузка будет минимальна, малозаметна.
2. Возможно глюк винды, что неудивительно особенно для Windows 10. В таком случае нужно либо откатиться на прошлый билд (гемор), либо отключать процесс в диспетчере, что может привести к новым глюкам. Да и процесс спокойно может восстанавливаться. Тогда единственный логичный выход — отключать службу, либо отключать в настройках (далее покажу как это сделать).
3. Просканировать комп системной утилитой System File Checker — она позволяет проверить системные файлы и в случае повреждений — восстановить их. Мини-инструкция: нажмите правой кнопкой по значку Пуск > выберите пункт запустить командную строку от имени администратора > напишите команду sfc /scannow и нажмите энтер. После проверки — перезагрузите комп.
4. Использование команды DISM (Deployment Image Servicing and Management). Честно — не уверен что поможет, но данный совет нашел на форуме Microsoft. Нажмите правой кнопкой по пуску — выберите пункт запуск командной строки от имени админа. В командную строку напишите одну команду, нажмите энтер, потом напишите вторую и также нажмите энтер. Команда первая: DISM.exe /Online /Cleanup-image /Scanhealth вторая: DISM.exe /Online /Cleanup-image /Restorehealth (надеюсь все понятно). Работа обеих команд может занять до получаса (зависит от мощности железа).
5. Использовать встроенный инструмент для поиска неполадок индексирования файлов (ниже покажу подробнее).

Штатное средство устранения проблем с индексированием

Некоторым юзерам данный способ реально помог избавиться от сильной нагрузки. Все таки отключать индексирование — тоже выход, однако быстрый поиск файлов — ведь комфортно.. хотя если у вас SSD — то индексирование и правда можно отключить..

1. Открываем Панель управления. Теперь в современной версии Windows 10 ее не так просто открыть, поэтому вот универсальный рецепт: зажмите Win + R, Напишите команду control либо control panel и нажмите ОК.
2. В панели находим значок Параметры индексирования. Запускаем.
3. Внизу будет ссылка — Устранение неполадок при поиске и индексировании. Нажимаем.
4. Галочками укажите проблемы, если индексирование тормозит ПК, тогда думаю стоит выставить все галки. После — нажимаем Далее.
5. Потом нужно будет указать краткое описание проблемы. Возможно эта инфа будет передана в Майкрософт.
6. В итоге будет произведен поиск проблем. Если будут найдены — то будет попытка их исправить. Если в конце проверки будет предложено запустить средство от имени администратора — попробуйте этот вариант.

Ссылка для запуска инструмента устранения неполадок:

Я думал у меня проблем нет — оказалось есть:

Best Practices for Creating Filter Handlers in Windows Search

Microsoft Windows Search uses filters to extract the content of items for inclusion in a full-text index. You can extend Windows Search to index new or proprietary file types by writing filter handlers to extract the content, and property handlers to extract the properties of files. Filters are associated with file types, as denoted by file name extensions, MIME types or class identifiers (CLSIDs). While one filter can handle multiple file types, each type works with only one filter.

This topic contains the following sections:

Native Code

In WindowsВ 7В and later, filters written in managed code are explicitly blocked. Filters MUST be written in native code due to potential CLR versioning issues with the process that multiple add-ins run in.

Secure Code Practices for Windows Search

The following are practices for writing secure applications for use with Windows Search.

For query applications:

• When writing search clients, you should choose the API that runs in a security context that allows the user the least privilege. For example, ASP pages can use the IXSSO query object, which runs as a user process.

For IFilters and Language Resources:

• If a new filter handler for a file type is being installed as a replacement for an existing filter registration, the installer should save the current registration and restore it if the new filter handler is uninstalled. There is no mechanism to chain filters. Hence, the new filter handler is responsible for replicating any necessary functionality of the old filter.
• IFilters, word breakers, and stemmers for Windows Search run in the Local Security context. They should be written to manage buffers and to stack correctly. All string copies must have explicit checks to guard against buffer overruns. You should always verify the allocated size of the buffer and test the size of the data against the size of the buffer. Buffer overruns are a common technique for exploiting code that does not enforce buffer size restrictions.
• IFilter, word breaker and stemmer components should never call the ExitProcess Function function or similar API that terminates a process and all its threads.
• Do not allocate or free resources in the DllMain entry point. This can lead to failures during low-resource stress tests.
• Code all objects to be thread-safe. Windows Search calls any one instance of a word breaker or stemmer in one thread at a time, but it may call multiple instances at the same time across multiple threads.
• Avoid creating temporary files or writing to the registry.
• If you use the Microsoft Visual C++ compiler, ensure that you compile your application using the /GS option. The /GS option is used to detect buffer overruns. The /GS option places security checks into the compiled code. For more information, see DllGetClassObject Function /GS (Buffer Security Check) in the Visual C++ Compiler Options section of the Platform SDK.

Filter Handlers that Ship with Windows

Microsoft supplies several standard filters with Windows Search. Clients call these filter handlers (which are implementations of the IFilter interface) to extract text and properties from a document.

This topic is organized as follows:

Windows Search Implementation Notes

In WindowsВ 7В and later, filters written in managed code are explicitly blocked. Filters MUST be written in native code due to potential CLR versioning issues with the process that multiple add-ins run in.

Windows 7 and 10 Implementation

In WindowsВ 7В and later, there is new behavior that occurs when registering a filter handler, property handler, or new extension. When a new property handler and/or filter handler is installed, files with the corresponding extensions are automatically re-indexed.

In WindowsВ 7В and later, we recommend that you install a filter handler in conjunction with its corresponding property handlers, and that you register the filter handler before the property handler. The registration of the property handler initiates immediate re-indexing of previously indexed files without first requiring a restart, and takes advantage of any previously registered filter handlers for the purpose of content indexing.

If only a filter handler is installed without a corresponding property handler, then automatic re-indexing occurs either after a restart of the indexing service, or a restart of the system.

For property description flags specific to WindowsВ 7, see the following reference topics: GETPROPERTYSTOREFLAGS, PROPDESC_COLUMNINDEX_TYPE and PROPDESC_SEARCHINFO_FLAGS.

Windows Vista Implementation

In WindowsВ Vista and earlier, installing an IFilter or property handler does not initiate a re-indexing of existing items unless an independent software vendor (ISV) explicitly calls a rebuild or re-indexing of matching URLs.

There are two major differences between legacy applications like Indexing Service and newer applications like Windows Search that you should be aware of when implementing filters:

• Use of the IPersistStream interface.
• Use of property handlers.

First, WindowsВ Vista and Windows Search 3.0 and later require you use IPersistStream for the following reasons:

• To ensure performance and future compatibility.
• To help increase security. Filters implemented with IPersistStream are more secure because the context in which the filter runs does not need the rights to open files on the disk or over the network.

While Windows Search uses only IPersistStream, you can also include IPersistFile Interface and/or IPersistStorage Interface implementations in your filters for backward compatibility.

The second major difference is that WindowsВ Vista and Windows Search 3.0 and later have a new Property System that uses property handlers to enumerate properties of items.

However, there are times when you need to implement a filter that handles both content and properties in order to:

• Support legacy MSSearch implementations.
• Traverse links.
• Preserve language information.
• Recursively filter embedded items.

In these situations, you need a full filter implementation, including the IFilter::GetValue method to access property values.

Legacy Implementation

As noted earlier, WindowsВ Vista and Windows Search include a new property system that encapsulates an item’s properties that is separate from an item’s content. This property system does not exist in earlier versions of MicrosoftВ Windows Desktop Search (WDS) 2.x. If your filter must support other applications as described above, it may need to handle both content and properties.

For more information on developing a compatible filter, see the following topics, IFilter (for legacy applications), and Developing Filter Add-ins (for legacy applications).

Windows Search Filters

Microsoft supplies several standard filters with Windows Search. The IFilter В DLL contents are summarized in the following table. Clicking the name of a filter handler takes you to the description for that IFilter implementation.

Filter handler	Files filtered	IFilter DLL
MIME Filter Handler	Multipurpose Internet Mail Extension (MIME)	mimefilt.dll
HTML Filter Handler	HTML 3.0 or earlier	nlhtml.dll
Document Filter Handler	Microsoft Word, Excel, PowerPoint	offfilt.dll
Plain Text Filter Handler	Plain text files — Default IFilter	query.dll
Binary or Null Filter Handler	Binary files — Null IFilter	query.dll

MIME Filter Handler

The MIME filter handler (in mimefilt.dll) extracts text and property information from files with the extensions .eml, .mht and .mhtml.

HTML Filter Handler

The HTML filter handler (in nlhtml.dll) extracts text and property information from the class «htmlfiles» so that it can be indexed by Windows Search. For a description of the association between IFilter and file type, see «Finding the IFilter DLL for a File» in Registering Filter Handlers.

You can use the META tag feature of HTML documents to convey special handling requests to the HTML IFilter. META tags occur near the beginning of an html file within the HEAD . /HEAD tags, as illustrated in the following example.

Some HTML META tags are automatically mapped to well known property set and property ID (property identifier (PID)) values so that queries on these properties will search the mapped contents. Some examples are listed in the following table. For a list of system properties that you can use for your file formats, see System-Defined Properties for Custom File Formats.

Property example	Mapped to
meta name=»author» content=»ruth»	The author property in the Summary Information property set.
meta name=»subject» content=»word processing»	The subject property in the Summary Information property set.
meta name=»keywords» content=»fonts, serif»	The keyword property in the Summary Information property set.
meta name=»ms.category» content=»fiction»	The category property in the document Summary Information property set.

Some features of the HTML IFilter are listed in the following table.

Task	Action	Example
Creating special abstracts from files	Use the META NAME=»DESCRIPTION». tag to instruct the IFilter» data-linktype=»external»>IFilter to use the string following the CONTENT keyword as the document abstract. [!Note] The filtering process can generate abstracts for each filtered file, which default to being a set of characters at the beginning of the file.
Preventing individual files from being filtered	Add a meta name tag to the file.
Setting the language code for a file (to ensure the system chooses the correct language word breakers and noise word files)	Add the following meta name tag to the file, where the content field specifies the appropriate language code (either in characters or by using the locale value).	Document Filter Handler The Document filter handler (in offilt.dll) filters files for some extensions of documents in Microsoft Office. These include files with the extensions .doc, .mdb, .ppt, and .xlt, for example. Plain Text Filter Handler For plain-text files, Windows Search uses the text filter handler, which filters both the system properties (such as file names) and the contents of a file. When a file type does not have an IFilter association in the registry, Windows Search indexes only the Shell properties for the file. However the user can use the Advanced Options in the Indexing Options control panel to Index Properties or Index Properties and File Contents. If the user chooses this option for a file type without an associated IFilter, the text filter handler is used to extract the content of the file. The text filter handler does not «understand» any document format; when filtering the contents of a file, it treats the file as a sequence of characters. It does check for the Unicode byte-order mark at the beginning of the file. Binary or Null Filter Handler When a registered binary file is encountered, the null filter handler is used. The null filter handler retrieves only the system properties. The contents of a binary file are not filtered. Examples of system properties are FileName, LastWriteTime, FileSize, and Attributes. Читайте также:  Долго включается компьютер windows 10 ssd Оцените статью Вам также может понравиться Windows или Linux: Что лучше выбрать? Есть много причин выбирать между Windows и Linux, но Файл владелец изменить linux Команда Chown в Linux Chown Command in Linux (File Установка шлюза по умолчанию linux Настройка сети вручную Содержание Краткое описание Чем разбить диск для linux ИТ База знаний Курс по Asterisk Полезно — Узнать IP — Правообладателям Политика конфиденциальности Контакты