tep_find_common_field(3) — Linux manual page
LIBTRACEEVENT(3) libtraceevent Manual LIBTRACEEVENT(3)
NAME
tep_find_common_field, tep_find_field, tep_find_any_field -
Search for a field in an event.
SYNOPSIS
#include <event-parse.h>
struct tep_format_field *tep_find_common_field(struct tep_event *event, const char *name);
struct tep_format_field *tep_find_field(struct tep_event_ormat *event, const char *name);
struct tep_format_field *tep_find_any_field(struct tep_event *event, const char *name);
DESCRIPTION
These functions search for a field with given name in an event.
The field returned can be used to find the field content from
within a data record.
The tep_find_common_field() function searches for a common field
with name in the event.
The tep_find_field() function searches for an event specific
field with name in the event.
The tep_find_any_field() function searches for any field with
name in the event.
RETURN VALUE
The tep_find_common_field(), tep_find_field() and
_tep_find_any_field() functions return a pointer to the found
field, or NULL in case there is no field with the requested name.
EXAMPLE
#include <event-parse.h>
...
void get_htimer_info(struct tep_handle *tep, struct tep_record *record)
{
struct tep_format_field *field;
struct tep_event *event;
long long softexpires;
int mode;
int pid;
event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
field = tep_find_common_field(event, "common_pid");
if (field == NULL) {
/* Cannot find "common_pid" field in the event */
} else {
/* Get pid from the data record */
pid = tep_read_number(tep, record->data + field->offset,
field->size);
}
field = tep_find_field(event, "softexpires");
if (field == NULL) {
/* Cannot find "softexpires" event specific field in the event */
} else {
/* Get softexpires parameter from the data record */
softexpires = tep_read_number(tep, record->data + field->offset,
field->size);
}
field = tep_find_any_field(event, "mode");
if (field == NULL) {
/* Cannot find "mode" field in the event */
} else
{
/* Get mode parameter from the data record */
mode = tep_read_number(tep, record->data + field->offset,
field->size);
}
}
...
FILES
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
Steven Rostedt <rostedt@goodmis.org[1]>, author of libtraceevent.
Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>, author of this man page.
REPORTING BUGS
Report bugs to <linux-trace-devel@vger.kernel.org[3]>
LICENSE
libtraceevent is Free Software licensed under the GNU LGPL 2.1
RESOURCES
https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
NOTES
1. rostedt@goodmis.org
mailto:rostedt@goodmis.org
2. tz.stoyanov@gmail.com
mailto:tz.stoyanov@gmail.com
3. linux-trace-devel@vger.kernel.org
mailto:linux-trace-devel@vger.kernel.org
COLOPHON
This page is part of the libtraceevent (Linux kernel trace event
library) project. Information about the project can be found at
⟨https://www.trace-cmd.org/⟩. If you have a bug report for this
manual page, see ⟨https://www.trace-cmd.org/⟩. This page was
obtained from the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git⟩
on 2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-05-17.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
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