linuxdebug/tools/lib/traceevent/Documentation/libtraceevent-event_get.txt

100 lines
2.5 KiB
Plaintext
Raw Permalink Normal View History

2024-07-16 15:50:57 +02:00
libtraceevent(3)
================
NAME
----
tep_get_event, tep_get_first_event, tep_get_events_count - Access events.
SYNOPSIS
--------
[verse]
--
*#include <event-parse.h>*
struct tep_event pass:[*]*tep_get_event*(struct tep_handle pass:[*]_tep_, int _index_);
struct tep_event pass:[*]*tep_get_first_event*(struct tep_handle pass:[*]_tep_);
int *tep_get_events_count*(struct tep_handle pass:[*]_tep_);
--
DESCRIPTION
-----------
The _tep_get_event()_ function returns a pointer to event at the given _index_.
The _tep_ argument is trace event parser context, the _index_ is the index of
the requested event.
The _tep_get_first_event()_ function returns a pointer to the first event.
As events are stored in an array, this function returns the pointer to the
beginning of the array. The _tep_ argument is trace event parser context.
The _tep_get_events_count()_ function returns the number of the events
in the array. The _tep_ argument is trace event parser context.
RETURN VALUE
------------
The _tep_get_event()_ returns a pointer to the event located at _index_.
NULL is returned in case of error, in case there are no events or _index_ is
out of range.
The _tep_get_first_event()_ returns a pointer to the first event. NULL is
returned in case of error, or in case there are no events.
The _tep_get_events_count()_ returns the number of the events. 0 is
returned in case of error, or in case there are no events.
EXAMPLE
-------
[source,c]
--
#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
int i,count = tep_get_events_count(tep);
struct tep_event *event, *events = tep_get_first_event(tep);
if (events == NULL) {
/* There are no events */
} else {
for (i = 0; i < count; i++) {
event = (events+i);
/* process events[i] */
}
/* Get the last event */
event = tep_get_event(tep, count-1);
}
--
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* <rostedt@goodmis.org>, author of *libtraceevent*.
*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page.
--
REPORTING BUGS
--------------
Report bugs to <linux-trace-devel@vger.kernel.org>
LICENSE
-------
libtraceevent is Free Software licensed under the GNU LGPL 2.1
RESOURCES
---------
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git