linux/tools/lib/traceevent/Documentation/libtraceevent-set_flag.txt
Tzvetomir Stoyanov 680ca343d2 tools lib traceevent: Man pages for tep_handler related APIs
Added 4 new man pages, describing libtraceevent APIs:

  tep_register_comm(),
  tep_override_comm(),
  tep_is_pid_registered(),
  tep_data_comm_from_pid(),
  tep_data_pid_from_comm(),
  tep_cmdline_pid(),
  tep_alloc(),
  tep_free(),
  tep_get_long_size(),
  tep_set_long_size(),
  tep_set_flag(),
  tep_clear_flag(),
  tep_test_flag()

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-4-tstoyanov@vmware.com
Link: http://lkml.kernel.org/r/20190510200106.420270952@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-05-15 16:36:47 -03:00

105 lines
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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* <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