tep_get_header_page_size, tep_get_header_timestamp_size, tep_is_old_format - Get the data stored in the

StevenRostedt <rostedt@goodmis.org[1]>, author of libtraceevent.
           TzvetomirStoyanov <tz.stoyanov@gmail.com[2]>, author of this man page.

       These functions retrieve information from kernel context, stored in tracefs events/header_page. Old
       kernels do not have header page info, so default values from user space context are used.

       The tep_get_header_page_size() function returns the size of a long integer, in kernel context. The tep
       argument is trace event parser context. This information is retrieved from tracefs events/header_page,
       "commit" field.

       The tep_get_header_timestamp_size() function returns the size of timestamps, in kernel context. The tep
       argument is trace event parser context. This information is retrieved from tracefs events/header_page,
       "timestamp" field.

       The tep_is_old_format() function returns true if the kernel predates the addition of events/header_page,
       otherwise it returns false.

           #include <event-parse.h>
           ...
           struct tep_handle *tep = tep_alloc();
           ...
                   int longsize;
                   int timesize;
                   bool old;

                   longsize = tep_get_header_page_size(tep);
                   timesize = tep_get_header_timestamp_size(tep);
                   old = tep_is_old_format(tep);

                   printf ("%s kernel is used to generate the tracing data.\n",
                           old?"Old":"New");
                   printf("The size of a long integer is %d bytes.\n", longsize);
                   printf("The timestamps size is %d bytes.\n", timesize);
           ...

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.

       libtraceevent is Free Software licensed under the GNU LGPL 2.1

       tep_get_header_page_size, tep_get_header_timestamp_size, tep_is_old_format - Get the data stored in the
       header page, in kernel context.

        1. rostedt@goodmis.orgmailto:rostedt@goodmis.org

        2. tz.stoyanov@gmail.commailto:tz.stoyanov@gmail.com

        3. linux-trace-devel@vger.kernel.orgmailto:linux-trace-devel@vger.kernel.org

libtraceevent 1.8.4                                12/24/2024                                   LIBTRACEEVENT(3)

       Report bugs to <linux-trace-devel@vger.kernel.org[3]>

https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/

       The tep_get_header_page_size() function returns the size of a long integer, in bytes.

       The tep_get_header_timestamp_size() function returns the size of timestamps, in bytes.

       The tep_is_old_format() function returns true, if an old kernel is used to generate the tracing data,
       which has no event/header_page. If the kernel is new, or tep is NULL, false is returned.

libtraceevent(3), trace-cmd(1)

#include<event-parse.h>

       int tep_get_header_page_size(struct tep_handle *tep);
       int tep_get_header_timestamp_size(struct tep_handle *tep);
       bool tep_is_old_format(struct tep_handle *tep);