[PATCH 44/73] tools lib traceevent: Man page for tep_parse_header_page()

From: Arnaldo Carvalho de Melo
Date: Fri May 17 2019 - 15:41:46 EST

From: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>

Create man page for tep_parse_header_page() libtraceevent API.

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: linux-trace-devel@xxxxxxxxxxxxxxx
Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-25-tstoyanov@xxxxxxxxxx
Link: http://lkml.kernel.org/r/20190510200110.093108279@xxxxxxxxxxx
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
.../libtraceevent-parse_head.txt | 82 +++++++++++++++++++
1 file changed, 82 insertions(+)
create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-parse_head.txt

diff --git a/tools/lib/traceevent/Documentation/libtraceevent-parse_head.txt b/tools/lib/traceevent/Documentation/libtraceevent-parse_head.txt
new file mode 100644
index 000000000000..c90f16c7d8e6
--- /dev/null
+++ b/tools/lib/traceevent/Documentation/libtraceevent-parse_head.txt
@@ -0,0 +1,82 @@
+tep_parse_header_page - Parses the data stored in the header page.
+*#include <event-parse.h>*
+int *tep_parse_header_page*(struct tep_handle pass:[*]_tep_, char pass:[*]_buf_, unsigned long _size_, int _long_size_);
+The _tep_parse_header_page()_ function parses the header page data from _buf_,
+and initializes the _tep_, trace event parser context, with it. The buffer
+_buf_ is with _size_, and is supposed to be copied from
+Some old kernels do not have header page info, in this case the
+_tep_parse_header_page()_ function can be called with _size_ equal to 0. The
+_tep_ context is initialized with default values. The _long_size_ can be used in
+this use case, to set the size of a long integer to be used.
+The _tep_parse_header_page()_ function returns 0 in case of success, or -1
+in case of an error.
+#include <event-parse.h>
+struct tep_handle *tep = tep_alloc();
+char *buf;
+int size;
+buf = read_file("/sys/kernel/tracing/events/header_page", &size);
+if (tep_parse_header_page(tep, buf, size, sizeof(unsigned long)) != 0) {
+ /* Failed to parse the header page */
+ Header file to include in order to have access to the library APIs.
+ Linker switch to add when building a program that uses the library.
+_libtraceevent(3)_, _trace-cmd(1)_
+*Steven Rostedt* <rostedt@xxxxxxxxxxx>, author of *libtraceevent*.
+*Tzvetomir Stoyanov* <tz.stoyanov@xxxxxxxxx>, author of this man page.
+Report bugs to <linux-trace-devel@xxxxxxxxxxxxxxx>
+libtraceevent is Free Software licensed under the GNU LGPL 2.1