xref: /aosp_15_r20/external/libtraceevent/Documentation/libtraceevent-event_list.txt (revision 436bf2bcd5202612ffffe471bbcc1f277cc8d28e)

libtraceevent(3)
================

NAME
----
tep_list_events, tep_list_events_copy -
Get list of events, sorted by given criteria.

SYNOPSIS
--------
[verse]
--
*#include <event-parse.h>*

enum *tep_event_sort_type* {
	_TEP_EVENT_SORT_ID_,
	_TEP_EVENT_SORT_NAME_,
	_TEP_EVENT_SORT_SYSTEM_,
};

struct tep_event pass:[*]pass:[*]*tep_list_events*(struct tep_handle pass:[*]_tep_, enum tep_event_sort_type _sort_type_);
struct tep_event pass:[*]pass:[*]*tep_list_events_copy*(struct tep_handle pass:[*]_tep_, enum tep_event_sort_type _sort_type_);
--

DESCRIPTION
-----------
The *tep_list_events()* function returns an array of pointers to the events,
sorted by the _sort_type_ criteria. The last element of the array is NULL.
The returned memory must not be freed, it is managed by the library.
The function is not thread safe. The _tep_ argument is trace event parser
context. The _sort_type_ argument is the required sort criteria:
[verse]
--
	_TEP_EVENT_SORT_ID_	- sort by the event ID.
	_TEP_EVENT_SORT_NAME_	- sort by the event (name, system, id) triplet.
	_TEP_EVENT_SORT_SYSTEM_	- sort by the event (system, name, id) triplet.
--

The *tep_list_events_copy()* is a thread safe version of _tep_list_events()_.
It has the same behavior, but the returned array is allocated internally and
must be freed by the caller. Note that the content of the array must not be
freed (see the EXAMPLE below).

RETURN VALUE
------------
The *tep_list_events()* function returns an array of pointers to events.
In case of an error, NULL is returned. The returned array must not be freed,
it is managed by the library.

The *tep_list_events_copy()* function returns an array of pointers to events.
In case of an error, NULL is returned. The returned array must be freed by
the caller.

EXAMPLE
-------
[source,c]
--
#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
int i;
struct tep_event_format **events;

i=0;
events = tep_list_events(tep, TEP_EVENT_SORT_ID);
if (events == NULL) {
	/* Failed to get the events, sorted by ID */
} else {
	while(events[i]) {
		/* walk through the list of the events, sorted by ID */
		i++;
	}
}

i=0;
events = tep_list_events_copy(tep, TEP_EVENT_SORT_NAME);
if (events == NULL) {
	/* Failed to get the events, sorted by name */
} else {
	while(events[i]) {
		/* walk through the list of the events, sorted by name */
		i++;
	}
	free(events);
}

...
--

FILES
-----
[verse]
--
*event-parse.h*
	Header file to include in order to have access to the library APIs.
*-ltraceevent*
	Linker switch to add when building a program that uses the library.
--

SEE ALSO
--------
*libtraceevent*(3), *trace-cmd*(1)

AUTHOR
------
[verse]
--
*Steven Rostedt* <[email protected]>, author of *libtraceevent*.
*Tzvetomir Stoyanov* <[email protected]>, author of this man page.
--
REPORTING BUGS
--------------
Report bugs to  <[email protected]>

LICENSE
-------
libtraceevent is Free Software licensed under the GNU LGPL 2.1

RESOURCES
---------
https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/