tep_read_number_field(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | EXAMPLE | FILES | SEE ALSO | AUTHOR | REPORTING BUGS | LICENSE | RESOURCES | NOTES | COLOPHON

LIBTRACEEVENT(3)          libtraceevent Manual          LIBTRACEEVENT(3)

NAME         top

       tep_read_number_field - Reads a number from raw data.

SYNOPSIS         top

       #include <event-parse.h>

       int tep_read_number_field(struct tep_format_field *field, const void *data, unsigned long long *value);

DESCRIPTION         top

       The tep_read_number_field() function reads the value of the field
       from the raw data and stores it in the value. The function sets
       the value according to the endianness of the raw data and the
       current machine and stores it in value.

RETURN VALUE         top

       The tep_read_number_field() function retunrs 0 in case of
       success, or -1 in case of an error.

EXAMPLE         top

           #include <event-parse.h>
           ...
           struct tep_handle *tep = tep_alloc();
           ...
           struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
           ...
           void process_record(struct tep_record *record)
           {
                   unsigned long long pid;
                   struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid");

                   if (tep_read_number_field(field_pid, record->data, &pid) != 0) {
                           /* Failed to get "common_pid" value */
                   }
           }
           ...

FILES         top

           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.

SEE ALSO         top

       libtraceevent(3), trace-cmd(1)

AUTHOR         top

           Steven Rostedt <rostedt@goodmis.org[1]>, author of libtraceevent.
           Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>, author of this man page.

REPORTING BUGS         top

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

LICENSE         top

       libtraceevent is Free Software licensed under the GNU LGPL 2.1

RESOURCES         top

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

NOTES         top

        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

COLOPHON         top

       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 2024-06-14.  (At that time, the date of the most recent commit
       that was found in the repository was 2024-05-17.)  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)