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Name

ULLA (Unified Link Layer API) - access link layer information

Synopsis

#include <ulla/lu.h>
ullaResultCode_t ullaRequestReflection(const ullaString_t uqlQuery, ullaResultId_t *urId);

Description

ullaRequestReflection can be used to display the possible link layer information available via from ULLA. The reflection interface can show the currently available tables, their attributes and commands, and semantical descriptions for each individual attribute and command.

Parameters

The following parameters have to be carefully considered:

urId 
A handle for the ullaResult returned.
uql_statement 
For the ullaRequestReflection method only the following statements are valid:
show_statement this statement is used to display the table list, a list of attribute descriptions of a table, or a list of command descriptions of a table.
Please find some examples below.

Return Vallue

On success, the function call returns a handle for the ULLA result at pre-allocated urId. The return value is ULLA_OK.

On error, the return value is negative.

The list of error codes is

ULLA_OK
everything is fine.

ULLA_NO_MEMORY
ran out of user space or kernel space RAM memory.

ULLA_INSUFICIENT_MEMORY
ran out of user space RAM memory.

ULLA_ERROR_IN_VALUE
a parameter is syntactically or semantically incorrect.

ULLA_ERROR_FAULT
general error.

ULLA_SEGMENTATION_FAULT
ULLA Core implementation error.

ULLA_CORE_NOT_PRESENT
the ULLA Core kernel module cannot be loaded.

ULLA_BUG
ULLA Core implementation bug.

Examples

Some examples for valid UQL-statements are given below:

How-to get a list of the available tables?

The list of registered table with ULLA is available from:
"SHOW TABLES;"

How-to get a list of the attribute descriptions from particular tables?

The list of attribute descriptions is quite comprehensive. The uql_statement is a show_statement like:
"SHOW ATTRIBUTES FROM p80211Link, ieee80221Link;"

How-to get a list of the command descriptions from particular tables?

Equivalent to the attributes there is also a somewhat less comprehensive command description available:
"SHOW COMMAND FROM ullaLinkProvider;"

See Also

ullaReflection(1) , ullaAttribute(1) , ullaCommand(1) , ullaSample(1) , ullaNotification(1) , ullaTools(1)

ulla(2) , uql(2) , ullaResult(2) , ullaTuple(2) , ullaRequestReflection(2) , ullaRequestAttribute(2) , ullaRequestCommand(2) , ullaRequestNotification(2) , ullaRequestSample(2) , ullaRequestLock(2) , ullaGetCoreDescriptor(2)

Conforming to

RWTH contribution to the GOLLUM project (http://www.ist-gollum.org). Compliant with ULLA C-API Version 1.0 (http://ulla.sourceforge.net).

Author

This man page was written by Marten Bandholz (mba@mobnets.rwth-aachen.de).


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