| libtraceevent(3) |
| ================ |
| |
| NAME |
| ---- |
| tep_find_common_field, tep_find_field, tep_find_any_field - |
| Search for a field in an event. |
| |
| SYNOPSIS |
| -------- |
| [verse] |
| -- |
| *#include <event-parse.h>* |
| |
| struct tep_format_field pass:[*]*tep_find_common_field*(struct tep_event pass:[*]_event_, const char pass:[*]_name_); |
| struct tep_format_field pass:[*]*tep_find_field*(struct tep_event_ormat pass:[*]_event_, const char pass:[*]_name_); |
| struct tep_format_field pass:[*]*tep_find_any_field*(struct tep_event pass:[*]_event_, const char pass:[*]_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 |
| ------- |
| [source,c] |
| -- |
| #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 |
| ----- |
| [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 |
