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NAME |SYNOPSIS |DESCRIPTION |RETURN VALUE |EXAMPLE |FILES |SEE ALSO |AUTHOR |REPORTING BUGS |LICENSE |RESOURCES |NOTES |COLOPHON | |
LIBTRACEEVENT(3) libtraceevent ManualLIBTRACEEVENT(3)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.
#include <event-parse.h> inttep_get_header_page_size(struct tep_handle *tep); inttep_get_header_timestamp_size(struct tep_handle *tep); booltep_is_old_format(struct tep_handle *tep);
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. Thetep_get_header_page_size()function returns the size of a long integer, in kernel context. Thetep argument is trace event parser context. This information is retrieved from tracefs events/header_page, "commit" field. Thetep_get_header_timestamp_size()function returns the size of timestamps, in kernel context. Thetep argument is trace event parser context. This information is retrieved from tracefs events/header_page, "timestamp" field. Thetep_is_old_format()function returns true if the kernel predates the addition of events/header_page, otherwise it returns false.
Thetep_get_header_page_size()function returns the size of a long integer, in bytes. Thetep_get_header_timestamp_size()function returns the size of timestamps, in bytes. Thetep_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, ortep is NULL, false is returned.
#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(3),trace-cmd(1)
Steven Rostedt<rostedt@goodmis.org[1]>, author oflibtraceevent.Tzvetomir Stoyanov<tz.stoyanov@gmail.com[2]>, author of this man page.
Report bugs to <linux-trace-devel@vger.kernel.org[3]>
libtraceevent is Free Software licensed under the GNU LGPL 2.1
https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
1. rostedt@goodmis.org mailto:rostedt@goodmis.org 2. tz.stoyanov@gmail.com mailto:tz.stoyanov@gmail.com 3. linux-trace-devel@vger.kernel.org mailto:linux-trace-devel@vger.kernel.org
This page is part of thelibtraceevent (Linux kernel trace event library) project. Information about the project can be found at ⟨https://www.trace-cmd.org/⟩. If you have a bug report for this manual page, see ⟨https://www.trace-cmd.org/⟩. This page was obtained from the project's upstream Git repository ⟨https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git⟩ on 2025-08-11. (At that time, the date of the most recent commit that was found in the repository was 2025-05-30.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which isnot part of the original manual page), send a mail to man-pages@man7.orglibtraceevent 1.7.3 09/24/2023LIBTRACEEVENT(3)HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH. | |