1libtraceevent(3)
  2================
  3
  4NAME
  5----
  6tep_find_common_field, tep_find_field, tep_find_any_field -
  7Search for a field in an event.
  8
  9SYNOPSIS
 10--------
 11[verse]
 12--
 13*#include <event-parse.h>*
 14
 15struct tep_format_field pass:[*]*tep_find_common_field*(struct tep_event pass:[*]_event_, const char pass:[*]_name_);
 16struct tep_format_field pass:[*]*tep_find_field*(struct tep_event_ormat pass:[*]_event_, const char pass:[*]_name_);
 17struct tep_format_field pass:[*]*tep_find_any_field*(struct tep_event pass:[*]_event_, const char pass:[*]_name_);
 18--
 19
 20DESCRIPTION
 21-----------
 22These functions search for a field with given name in an event. The field
 23returned can be used to find the field content from within a data record.
 24
 25The _tep_find_common_field()_ function searches for a common field with _name_
 26in the _event_.
 27
 28The _tep_find_field()_ function searches for an event specific field with
 29_name_ in the _event_.
 30
 31The _tep_find_any_field()_ function searches for any field with _name_ in the
 32_event_.
 33
 34RETURN VALUE
 35------------
 36The _tep_find_common_field(), _tep_find_field()_ and _tep_find_any_field()_
 37functions return a pointer to the found field, or NULL in case there is no field
 38with the requested name.
 39
 40EXAMPLE
 41-------
 42[source,c]
 43--
 44#include <event-parse.h>
 45...
 46void get_htimer_info(struct tep_handle *tep, struct tep_record *record)
 47{
 48	struct tep_format_field *field;
 49	struct tep_event *event;
 50	long long softexpires;
 51	int mode;
 52	int pid;
 53
 54	event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
 55
 56	field = tep_find_common_field(event, "common_pid");
 57	if (field == NULL) {
 58		/* Cannot find "common_pid" field in the event */
 59	} else {
 60		/* Get pid from the data record */
 61		pid = tep_read_number(tep, record->data + field->offset,
 62				      field->size);
 63	}
 64
 65	field = tep_find_field(event, "softexpires");
 66	if (field == NULL) {
 67		/* Cannot find "softexpires" event specific field in the event */
 68	} else {
 69		/* Get softexpires parameter from the data record */
 70		softexpires = tep_read_number(tep, record->data + field->offset,
 71					      field->size);
 72	}
 73
 74	field = tep_find_any_field(event, "mode");
 75	if (field == NULL) {
 76		/* Cannot find "mode" field in the event */
 77	} else
 78	{
 79		/* Get mode parameter from the data record */
 80		mode = tep_read_number(tep, record->data + field->offset,
 81				       field->size);
 82	}
 83}
 84...
 85--
 86
 87FILES
 88-----
 89[verse]
 90--
 91*event-parse.h*
 92	Header file to include in order to have access to the library APIs.
 93*-ltraceevent*
 94	Linker switch to add when building a program that uses the library.
 95--
 96
 97SEE ALSO
 98--------
 99_libtraceevent(3)_, _trace-cmd(1)_
100
101AUTHOR
102------
103[verse]
104--
105*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*.
106*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page.
107--
108REPORTING BUGS
109--------------
110Report bugs to  <linux-trace-devel@vger.kernel.org>
111
112LICENSE
113-------
114libtraceevent is Free Software licensed under the GNU LGPL 2.1
115
116RESOURCES
117---------
118https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git