[PATCH 7/9] libtracefs man pages: helper APIs for working with trace instances.

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

Documented APIs:
tracefs_instance_get_name()
tracefs_instances_walk()
tracefs_instance_exists()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 Documentation/libtracefs-instances-utils.txt | 111 +++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 Documentation/libtracefs-instances-utils.txt

diff --git a/Documentation/libtracefs-instances-utils.txt b/Documentation/libtracefs-instances-utils.txt
new file mode 100644
index 0000000..1630d5c
--- /dev/null
+++ b/Documentation/libtracefs-instances-utils.txt
@@ -0,0 +1,111 @@
+libtracefs(3)
+=============
+
+NAME
+----
+tracefs_instance_get_name, tracefs_instances_walk, tracefs_instance_exists -
+Helper functions for working with tracing instances.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <tracefs.h>*
+
+const char pass:[*]*tracefs_instance_get_name*(struct tracefs_instance pass:[*]_instance_);
+int *tracefs_instances_walk*(int (pass:[*]_callback_)(const char pass:[*], void pass:[*]), void pass:[*]_context)_;
+bool *tracefs_instance_exists*(const char pass:[*]_name_);
+
+--
+
+DESCRIPTION
+-----------
+Helper functions for working with trace instances.
+
+The _tracefs_instance_get_name()_ function returns the name of the given _instance_.
+Note that the top instance has no name, the function returns NULL for it.
+
+The _tracefs_instances_walk()_ function walks through all configured tracing
+instances in the system and calls _callback_ for each one of them. The _context_
+argument is passed to the _callback_, together with the instance name. If the
+_callback_ returns non-zero, the iteration stops.
+
+The _tracefs_instance_exists()_ function checks if an instance with given _name_
+exists in the system.
+
+RETURN VALUE
+------------
+The _tracefs_instance_get_name()_ returns string or NULL in case of the top
+instance. The returned string must _not_ be freed.
+
+The _tracefs_instances_walk()_ function returns 0, if all instances were iterated, 1
+if the iteration was stopped by the _callback_, or -1 in case of an error.
+
+The _tracefs_instance_exists()_ returns true if an instance with given name
+exists in the system or false otherwise.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <tracefs.h>
+
+struct tracefs_instance *inst;
+....
+char *name = tracefs_instance_get_name(inst);
+
+	if(name) {
+		/* Got name of the instance */
+	}
+
+...
+static int instance_walk(char *name, void *context)
+{
+	/* Got instance with name */
+	return 0;
+}
+...
+	if (tracefs_instances_walk(instance_walk, NULL) < 0) {
+		/* Error walking through the instances */
+	}
+...
+	if (tracefs_instance_exists("foo")) {
+		/* There is instance with name foo in the system */
+	} else {
+		/* There is no instance with name foo in the system */
+	}
+--
+FILES
+-----
+[verse]
+--
+*tracefs.h*
+	Header file to include in order to have access to the library APIs.
+*-ltracefs*
+	Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+_libtracefs(3)_,
+_libtraceevent(3)_,
+_trace-cmd(1)_
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@goodmis.org>
+*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>
+--
+REPORTING BUGS
+--------------
+Report bugs to  <linux-trace-devel@vger.kernel.org>
+
+LICENSE
+-------
+libtracefs is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
\ No newline at end of file
-- 
2.28.0