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

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

NAME
----
tep_is_bigendian, tep_is_local_bigendian, tep_set_local_bigendian - Get / set
the endianness of the local machine.

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

enum *tep_endian* {
	TEP_LITTLE_ENDIAN = 0,
	TEP_BIG_ENDIAN
};

int *tep_is_bigendian*(void);
bool *tep_is_local_bigendian*(struct tep_handle pass:[*]_tep_);
void *tep_set_local_bigendian*(struct tep_handle pass:[*]_tep_, enum tep_endian _endian_);
--

DESCRIPTION
-----------

The *tep_is_bigendian()* gets the endianness of the machine, executing
the function.

The *tep_is_local_bigendian()* function gets the endianness of the local
machine, saved in the _tep_ handler. The _tep_ argument is the trace event
parser context. This API is a bit faster than *tep_is_bigendian()*, as it
returns cached endianness of the local machine instead of checking it each time.

The *tep_set_local_bigendian()* function sets the endianness of the local
machine in the _tep_ handler. The _tep_ argument is trace event parser context.
The _endian_ argument is the endianness:
[verse]
--
	_TEP_LITTLE_ENDIAN_ - the machine is little endian,
	_TEP_BIG_ENDIAN_ - the machine is big endian.
--

RETURN VALUE
------------
The *tep_is_bigendian()* function returns non zero if the endianness of the
machine, executing the code, is big endian and zero otherwise.

The *tep_is_local_bigendian()* function returns true, if the endianness of the
local machine, saved in the _tep_ handler, is big endian, or false otherwise.

EXAMPLE
-------
[source,c]
--
#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
	if (tep_is_bigendian())
		tep_set_local_bigendian(tep, TEP_BIG_ENDIAN);
	else
		tep_set_local_bigendian(tep, TEP_LITTLE_ENDIAN);
...
	if (tep_is_local_bigendian(tep))
		printf("This machine you are running on is bigendian\n");
	else
		printf("This machine you are running on is little endian\n");

--

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/