1LIBTRACEEVENT(3) libtraceevent Manual LIBTRACEEVENT(3)
2
6 tep_find_common_field, tep_find_field, tep_find_any_field - Search for
7 a field in an event.
8
10 #include <event-parse.h>
11 struct tep_format_field *tep_find_common_field(struct tep_event *event, const char *name);
13 struct tep_format_field *tep_find_field(struct tep_event_ormat *event, const char *name);
14 struct tep_format_field *tep_find_any_field(struct tep_event *event, const char *name);
15
17 These functions search for a field with given name in an event. The
18 field returned can be used to find the field content from within a data
19 record.
20 The tep_find_common_field() function searches for a common field with
22 name in the event.
23 The tep_find_field() function searches for an event specific field with
25 name in the event.
26 The tep_find_any_field() function searches for any field with name in
28 the event.
29
31 The tep_find_common_field(), _tep_find_field() and tep_find_any_field()
32 functions return a pointer to the found field, or NULL in case there is
33 no field with the requested name.
34
36 #include <event-parse.h>
37 ...
38 void get_htimer_info(struct tep_handle *tep, struct tep_record *record)
39 {
40 struct tep_format_field *field;
41 struct tep_event *event;
42 long long softexpires;
43 int mode;
44 int pid;
45 event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
47 field = tep_find_common_field(event, "common_pid");
49 if (field == NULL) {
50 /* Cannot find "common_pid" field in the event */
51 } else {
52 /* Get pid from the data record */
53 pid = tep_read_number(tep, record->data + field->offset,
54 field->size);
55 }
56 field = tep_find_field(event, "softexpires");
58 if (field == NULL) {
59 /* Cannot find "softexpires" event specific field in the event */
60 } else {
61 /* Get softexpires parameter from the data record */
62 softexpires = tep_read_number(tep, record->data + field->offset,
63 field->size);
64 }
65 field = tep_find_any_field(event, "mode");
67 if (field == NULL) {
68 /* Cannot find "mode" field in the event */
69 } else
70 {
71 /* Get mode parameter from the data record */
72 mode = tep_read_number(tep, record->data + field->offset,
73 field->size);
74 }
75 }
76 ...
77
79 event-parse.h
80 Header file to include in order to have access to the library APIs.
81 -ltraceevent
82 Linker switch to add when building a program that uses the library.
83
85 libtraceevent(3), trace-cmd(1)
86
88 Steven Rostedt <rostedt@goodmis.org[1]>, author of libtraceevent.
89 Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>, author of this man page.
90
92 Report bugs to <linux-trace-devel@vger.kernel.org[3]>
93
95 libtraceevent is Free Software licensed under the GNU LGPL 2.1
96
98 https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
99
101 1. rostedt@goodmis.org
102 mailto:rostedt@goodmis.org
103 2. tz.stoyanov@gmail.com
105 mailto:tz.stoyanov@gmail.com
106 3. linux-trace-devel@vger.kernel.org
108 mailto:linux-trace-devel@vger.kernel.org
109libtraceevent 1.1.1 02/08/2021 LIBTRACEEVENT(3)