libtracefs: Implement functions to work on event directory files

Add the following functions:

 tracefs_event_get_file() to easily put together a path to a file in the
            event directory.

 tracefs_event_file_read() to easily read the content from a file in the
            event directory.

 tracefs_event_file_write() to easily write content to a file in the
            event directory.

 tracefs_event_file_append() to easily append content to a file in the
            event directory.

 tracefs_event_file_clear() to easily clear the content of a file in the
            event directory.

 tracefs_event_file_exists() to easily know if a file exists in the
            event directory.

Link: https://lore.kernel.org/linux-trace-devel/20210707031110.249759-3-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/include/tracefs.h b/include/tracefs.h
index 6b9a76c..afbfd4e 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -102,6 +102,25 @@ int tracefs_iterate_raw_events(struct tep_handle *tep,
 				void *callback_context);
 void tracefs_iterate_stop(struct tracefs_instance *instance);
 
+char *tracefs_event_get_file(struct tracefs_instance *instance,
+			     const char *system, const char *event,
+			     const char *file);
+char *tracefs_event_file_read(struct tracefs_instance *instance,
+			      const char *system, const char *event,
+			      const char *file, int *psize);
+int tracefs_event_file_write(struct tracefs_instance *instance,
+			     const char *system, const char *event,
+			     const char *file, const char *str);
+int tracefs_event_file_append(struct tracefs_instance *instance,
+			      const char *system, const char *event,
+			      const char *file, const char *str);
+int tracefs_event_file_clear(struct tracefs_instance *instance,
+			     const char *system, const char *event,
+			     const char *file);
+bool tracefs_event_file_exists(struct tracefs_instance *instance,
+			       const char *system, const char *event,
+			       const char *file);
+
 char **tracefs_tracers(const char *tracing_dir);
 
 struct tep_handle *tracefs_local_events(const char *tracing_dir);