Documented APIs: tracefs_get_tracing_file() tracefs_put_tracing_file() tracefs_get_tracing_dir() tracefs_find_tracing_dir() Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx> --- Documentation/libtracefs-files.txt | 97 ++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 Documentation/libtracefs-files.txt diff --git a/Documentation/libtracefs-files.txt b/Documentation/libtracefs-files.txt new file mode 100644 index 0000000..8bf9d75 --- /dev/null +++ b/Documentation/libtracefs-files.txt @@ -0,0 +1,97 @@ +libtracefs(3) +============= + +NAME +---- +tracefs_get_tracing_file, tracefs_put_tracing_file, tracefs_tracing_dir - +Find locations of trace directory and files. + +SYNOPSIS +-------- +[verse] +-- +*#include <tracefs.h>* + +char pass:[*]*tracefs_get_tracing_file*(const char pass:[*]_name_); +void *tracefs_put_tracing_file*(char pass:[*]_name_); +const char pass:[*]*tracefs_tracing_dir*(void); +-- + +DESCRIPTION +----------- +This set of APIs can be used to find the full path of the trace file +system mount point and trace files in it. + +The _tracefs_get_tracing_file()_ function returns the full path of the +file with given _name_ in the trace file system. The function works +only with files in the trasefs main directory, it is not trace instance +aware. It is recommended to use _tracefs_instance_get_file()_ and +_tracefs_instance_get_dir()_ instead. The returned string must be freed +with _tracefs_put_tracing_file()_. + +The _tracefs_put_tracing_file()_ function frees trace file name, +returned by _tracefs_get_tracing_file()_. + +The _tracefs_tracing_dir()_ function returns the full path to the +trace file system. In the first function call, the mount point of the +tracing file system is located, cached and returned. It will mount it, +if it is not mounted. On any subsequent call the cached path is returned. +The return string must _not_ be freed. + +RETURN VALUE +------------ +The _tracefs_get_tracing_file()_ function returns a string or NULL in case +of an error. The returned string must be freed with _tracefs_put_tracing_file()_. + +The _tracefs_tracing_dir()_ function returns a constant string or NULL +in case of an error. The returned string must _not_ be freed. + +EXAMPLE +------- +[source,c] +-- +#include <tracefs.h> +... +char *trace_on = tracefs_get_tracing_file("tracing_on"); + if (trace_on) { + ... + tracefs_put_tracing_file(trace_on); + } +... +const char *trace_dir = tracefs_tracing_dir(); + +-- +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@xxxxxxxxxxx> +*Tzvetomir Stoyanov* <tz.stoyanov@xxxxxxxxx> +-- +REPORTING BUGS +-------------- +Report bugs to <linux-trace-devel@xxxxxxxxxxxxxxx> + +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