Re: [PATCH v5 15/30] tools/lib/traceevent: Man pages for event find APIs

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 12 Apr 2019 16:37:56 +0300
Tzvetomir Stoyanov <tstoyanov@vmware.com> wrote:

> Create man pages for libtraceevent APIs:
>   tep_find_event()
>   tep_find_event_by_name()
>   tep_find_event_by_record()
> 
> Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
> ---
>  .../libtraceevent-event_find.txt              | 101 ++++++++++++++++++
>  1 file changed, 101 insertions(+)
>  create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-event_find.txt
> 
> diff --git a/tools/lib/traceevent/Documentation/libtraceevent-event_find.txt b/tools/lib/traceevent/Documentation/libtraceevent-event_find.txt
> new file mode 100644
> index 000000000000..797a5cb4e38a
> --- /dev/null
> +++ b/tools/lib/traceevent/Documentation/libtraceevent-event_find.txt
> @@ -0,0 +1,101 @@
> +libtraceevent(3)
> +================
> +
> +NAME
> +----
> +tep_find_event,tep_find_event_by_name,tep_find_event_by_record -
> +Find events by given key.
> +
> +SYNOPSIS
> +--------
> +[verse]
> +--
> +*#include <event-parse.h>*
> +
> +struct tep_event pass:[*]*tep_find_event*(struct tep_handle pass:[*]_tep_, int _id_);
> +struct tep_event pass:[*]*tep_find_event_by_name*(struct tep_handle pass:[*]_tep_, const char pass:[*]_sys_, const char pass:[*]_name_);
> +struct tep_event pass:[*]*tep_find_event_by_record*(struct tep_handle pass:[*]_tep_, struct tep_record pass:[*]_record_);
> +--
> +
> +DESCRIPTION
> +-----------
> +This set of functions can be used to search for an event, based on a given
> +criteria. All functions require a pointer to a _tep_, trace event parser
> +context.
> +
> +The _tep_find_event()_ function searches for an event by given event _id_.

I would state that the id is the number that corresponds to the ID:
number that is found in the tracefs event format file.

-- Steve

> +
> +The tep_find_event_by_name()_ function searches for an event by given
> +event _name_, under the system _sys_. If the _sys_ is NULL (not specified),
> +the first event with _name_ is returned.
> +
> +The tep_find_event_by_record()_ function searches for an event from a given
> +_record_.
> +
> +RETURN VALUE
> +------------
> +All these functions return a pointer to the found event, or NULL if there is no
> +such event.
> +
> +EXAMPLE
> +-------
> +[source,c]
> +--
> +#include <event-parse.h>
> +...
> +struct tep_handle *tep = tep_alloc();
> +...
> +struct tep_event *event;
> +
> +event = tep_find_event(tep, 1857);
> +if (event == NULL) {
> +	/* There is no event with ID 1857 */
> +}
> +
> +event = tep_find_event_by_name(tep, "kvm", "kvm_exit");
> +if (event == NULL) {
> +	/* There is no kvm_exit event, from kvm system */
> +}
> +
> +void event_from_record(struct tep_record *record)
> +{
> + struct tep_event *event = tep_find_event_by_record(tep, record);
> +	if (event == NULL) {
> +		/* There is no event from given record */
> +	}
> +}
> +...
> +--
> +
> +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