Scope Attributes

You can specify the following types of scopes in your message patterns:

1. Scope to a session only.

2. Scope to a file only.

3. Scope only to a file in a particular session.

4. Scope to either or both a file and a session.

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Note -

File scopes are restricted to NFS and UFS file systems; you cannot scope a file across other types of file systems (for example, a tmpfs file system).

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Scoping to a Session Only

The type TT_SESSION scopes to a session only. Static session-scoped patterns require an explicit tt_session_join call to set the scope value; dynamic session-scoped patterns can be set with either the tt_session_join call or the tt_pattern_session_add call.

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Note -

The session specified by these calls must be the default session.

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Example 3-1 shows a static session-scoped pattern; Example 3-2 shows a dynamic session-scoped pattern.

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Example 3-1 Static Session-Scoped Pattern

Obtain procid	tt_open();
Ptype is scoped to session	tt_ptype_declare(ptype);
Join session	tt_session_join(tt_default_session());

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Example 3-2 Dynamic Session-Scoped Pattern with a File Attribute

Obtain procid	tt_open();
Create pattern	Tt_pattern pat = tt_create_pattern();
Add scope to pattern	tt_pattern_scope_add(pat, TT_SESSION);
Add session to pattern	tt_pattern_session_add (tt_default_session());
Register pattern	tt_pattern_register(pat);

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Scoping to a File Only

The type TT_FILE scopes to a file only. Example 3-3 shows a static file-scoped pattern; Example 3-4 shows a dynamic file-scoped pattern.

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Example 3-3 Static File-Scoped Pattern

Obtain procid	tt_open();
Ptype is scoped to file	tt_ptype_declare(ptype);
Join file	tt_file_join(file);

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Example 3-4 Dynamic File-Scoped Pattern

Obtain procid	tt_open();
Create pattern	Tt_pattern pat = tt_create_pattern();
Add scope to pattern	tt_pattern_scope_add(pat, TT_FILE);
Add file to pattern	tt_pattern_file_add (pat, file);
Register pattern	tt_pattern_register(pat);

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Scoping to a File in a Session

The type TT_FILE_IN_SESSION scopes to the specified file in the specified session only. A pattern with this scope set will only match messages that are scoped to both the file and the session. Example 3-5 adds the session and then registers the pattern.

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Example 3-5 Adding a Session to the TT_FILE_IN_SESSION-Scoped Pattern

Obtain procid	tt_open();
Create pattern	Tt_pattern pat = tt_create_pattern();
Add scope to pattern	tt_pattern_scope_add(pat,TT_FILE_IN_SESSION);
Add file to pattern	tt_pattern_file_add(pat, file);
Add session to pattern	tt_pattern_session_add(pat, tt_default_session());
Register pattern	tt_pattern_register(pat);

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Example 3-6 registers the pattern and then joins a session.

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Example 3-6 Joining a Session to Set the Session of a TT_FILE_IN_SESSION-Scoped Pattern

Obtain procid	tt_open();
Create pattern	Tt_pattern pat = tt_create_pattern();
Add scope to pattern	tt_pattern_scope_add(pat, TT_FILE_IN_SESSION);
Add file to pattern	tt_pattern_file_add(pat, file);
Register pattern	tt_pattern_register(pat);
Join session	tt_session_join(tt_default_session());

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Example 3-7 sets the scope value for a static pattern.

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Example 3-7 Setting the Scope Value for a TT_FILE_IN_SESSION Static Pattern

Obtain procid	tt_open();
Declare Ptype	Tt_ptype_declare(ptype);
Join File	tt_file_join(file);
Join session	tt_session_join(tt_default_session());

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Scoping to a File and/or a Session

A TT_BOTH-scoped pattern will match messages that are scoped to the file, the session, or the file and the session. However, when you use this scope, you must explicitly make a tt_file_join call; otherwise, the ToolTalk service will only match messages that are scoped to both the file and session of the registered pattern. Example 3-8 and Example 3-9 show examples of how to use this scope.

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Example 3-8 A Dynamic Pattern that Uses the TT_BOTH Scope

Obtain procid	tt_open();
Create pattern	Tt_pattern pat = tt_create_pattern();
Add scope to pattern	tt_pattern_scope_add(pat, TT_BOTH);
Add session to pattern	tt_pattern_session_add(pat,tt_default_session());
Add file to pattern	tt_pattern_file_add (pat, file);
Register pattern	tt_pattern_register(pat);

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Example 3-9 A Static Pattern that Uses the TT_BOTH Scope

Obtain procid	tt_open();
Declare Ptype	Tt_ptype_declare(ptype);
Join file	tt_file_join(file);
Join session	tt_session_join(tt_default_session());

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Adding Files to Scoped Patterns

To match TT_SESSION-scoped messages and TT_SESSION-scoped patterns that have the same file attributes, you can add file attributes to TT_SESSION-scoped patterns with the tt_pattern_file_add call, as shown in Example 3-10.

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Note -

The file attribute values do not affect the scope of the pattern.

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Example 3-10 Adding Two File Attributes to a Session-Scoped Pattern

Obtain procid	tt_open();
Create pattern	Tt_pattern pat = tt_create_pattern();
Add scope to pattern	tt_pattern_scope_add(pat, TT_SESSION);
Add session to pattern	tt_pattern_session_add(tt_default_session());
Add first file attribute to pattern	tt_pattern_file_add(pat, file1);
Add second file attribute to pattern	tt_pattern_file_add(pat, file2);
Register pattern	tt_pattern_register(pat);

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