IBM Carrier Grade X3650 T, User Manual

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IBM® Carrier Grade Server X3650 T
Revision 3.0 91
17.2.8.2.2 syscon_log_query_get()
The syscon_log_query_get () function shall store a textual query expression to the buffer pointed to by the
qsbuf argument. This expression shall be functionally equivalent to the one that was passed to
syscon_log_query_create () to create the query object pointed to by the query argument.
The buffer pointed to by qsbuf is assumed to be at least qslen bytes long. If qsbuf is equal to NULL , or
the buffer is too small to hold the returned character string, the syscon_log_query_get () function shall fail.
In any case, if the reqlen argument is not NULL , the length in bytes of the query expression (including the
terminating null character) shall be stored in the location pointed to by reqlen .
If the purpose argument is not NULL , syscon_log_query_get () shall store the value of the indicated query
object’s purpose flags to the location pointed to by purpose .
If the query object was not initialized by syscon_log_query_create (), then the result of the call to
syscon_log_query_get () shall be undefined.
17.2.8.2.3 Query Expressions: Overview
The following sections define the syntax and semantics of a “general” query expression. Limited queries
are defined in section 20.4.8.2.8.
A simple query expression is a single test of the form " attribute-name op val ", where
•
attribute-name is the name of an event attribute,
•
op is a comparison operator such as
==
or
<
, and
•
val is the reference value for the test – typically a symbolic constant, an integer constant, or a
string literal.
An event record is said to pass the test if the comparison between the reference value and the value of
the named attribute in the event record evaluates to true (non-zero).
More complex queries can be constructed by combining queries using operators such as && and
||
(“and” and “or”, respectively), or by negating a query using the '
!
' operator. An event record is said to
match a query if the query expression evaluates to true (non-zero) for that record.