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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | EXAMPLE | FILES | SEE ALSO | AUTHOR | REPORTING BUGS | LICENSE | RESOURCES | NOTES | COLOPHON |
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LIBTRACEEVENT(3) libtraceevent Manual LIBTRACEEVENT(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>
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);
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.
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.
#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 of libtraceevent.
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 the libtraceevent (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 2023-12-22. (At that time, the date of the most recent commit
that was found in the repository was 2023-06-07.) 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 is not part of the original
manual page), send a mail to man-pages@man7.org
libtraceevent 1.7.3 09/24/2023 LIBTRACEEVENT(3)
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HTML rendering created 2023-12-22 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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