libtracefs(3)
=============

NAME
----
tracefs_get_tracing_file, tracefs_put_tracing_file, tracefs_tracing_dir -
Find locations of trace directory and files.

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

char pass:[*]*tracefs_get_tracing_file*(const char pass:[*]_name_);
void *tracefs_put_tracing_file*(char pass:[*]_name_);
const char pass:[*]*tracefs_tracing_dir*(void);
--

DESCRIPTION
-----------
This set of APIs can be used to find the full path of the trace file
system mount point and trace files in it.

The _tracefs_get_tracing_file()_ function returns the full path of the
file with given _name_ in the trace file system. The function works
only with files in the trasefs main directory, it is not trace instance
aware. It is recommended to use _tracefs_instance_get_file()_ and
_tracefs_instance_get_dir()_ instead. The returned string must be freed
with _tracefs_put_tracing_file()_.

The _tracefs_put_tracing_file()_ function frees trace file name,
returned by _tracefs_get_tracing_file()_.

The _tracefs_tracing_dir()_ function returns the full path to the
trace file system. In the first function call, the mount point of the
tracing file system is located, cached and returned. It will mount it,
if it is not mounted. On any subsequent call the cached path is returned.
The return string must _not_ be freed.

RETURN VALUE
------------
The _tracefs_get_tracing_file()_ function returns a string or NULL in case
of an error. The returned string must be freed with _tracefs_put_tracing_file()_.

The _tracefs_tracing_dir()_ function returns a constant string or NULL
in case of an error. The returned string must _not_ be freed.

EXAMPLE
-------
[source,c]
--
#include <tracefs.h>
...
char *trace_on = tracefs_get_tracing_file("tracing_on");
	if (trace_on) {
		...
		tracefs_put_tracing_file(trace_on);
	}
...
const char *trace_dir = tracefs_tracing_dir();

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

SEE ALSO
--------
_libtracefs(3)_,
_libtraceevent(3)_,
_trace-cmd(1)_

AUTHOR
------
[verse]
--
*Steven Rostedt* <rostedt@goodmis.org>
*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>
--
REPORTING BUGS
--------------
Report bugs to  <linux-trace-devel@vger.kernel.org>

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

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

COPYING
-------
Copyright \(C) 2020 VMware, Inc. Free use of this software is granted under
the terms of the GNU Public License (GPL).
