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

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

NAME
----
tep_set_flag, tep_clear_flag, tep_test_flag -
Manage flags of trace event parser context.

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

enum *tep_flag* {
	_TEP_NSEC_OUTPUT_,
	_TEP_DISABLE_SYS_PLUGINS_,
	_TEP_DISABLE_PLUGINS_
};
void *tep_set_flag*(struct tep_handle pass:[*]_tep_, enum tep_flag _flag_);
void *tep_clear_flag*(struct tep_handle pass:[*]_tep_, enum tep_flag _flag_);
bool *tep_test_flag*(struct tep_handle pass:[*]_tep_, enum tep_flag _flag_);
--

DESCRIPTION
-----------
Trace event parser context flags are defined in *enum tep_flag*:
[verse]
--
_TEP_NSEC_OUTPUT_ - print event's timestamp in nano seconds, instead of micro seconds.
_TEP_DISABLE_SYS_PLUGINS_ - disable plugins, located in system's plugin
			directory. This directory is defined at library compile
			time, and usually depends on library installation
			prefix: (install_preffix)/lib/traceevent/plugins
_TEP_DISABLE_PLUGINS_ - disable all library plugins:
			- in system's plugin directory
			- in directory, defined by the environment variable _TRACEEVENT_PLUGIN_DIR_
			- in user's home directory, _~/.traceevent/plugins_
--
Note: plugin related flags must me set before calling *tep_load_plugins()* API.

The *tep_set_flag()* function sets _flag_ to _tep_ context.

The *tep_clear_flag()* function clears _flag_ from _tep_ context.

The *tep_test_flag()* function tests if _flag_ is set to _tep_ context.

RETURN VALUE
------------
*tep_test_flag()* function returns true if _flag_ is set, false otherwise.

EXAMPLE
-------
[source,c]
--
#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
/* Print timestamps in nanoseconds */
tep_set_flag(tep,  TEP_NSEC_OUTPUT);
...
if (tep_test_flag(tep, TEP_NSEC_OUTPUT)) {
	/* print timestamps in nanoseconds */
} else {
	/* print timestamps in microseconds */
}
...
/* Print timestamps in microseconds */
tep_clear_flag(tep, TEP_NSEC_OUTPUT);
...
--
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/