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NAME |SYNOPSIS |DESCRIPTION |EXAMPLE |FILES |SEE ALSO |AUTHOR |REPORTING BUGS |LICENSE |RESOURCES |NOTES |COLOPHON | |
LIBTRACEEVENT(3) libtraceevent ManualLIBTRACEEVENT(3)tep_print_event - Writes event information into a trace sequence.
#include <event-parse.h>#include <trace-seq.h> voidtep_print_event(struct tep_handle *tep, struct trace_seq*s, struct tep_record *record, const char *fmt,...)
Thetep_print_event()function parses the event information of the givenrecord and writes it into the trace sequences, according to the format stringfmt. The desired information is specified after the format string. Thefmt is printf-like format string, following arguments are supported: TEP_PRINT_PID, "%d" - PID of the event. TEP_PRINT_CPU, "%d" - Event CPU. TEP_PRINT_COMM, "%s" - Event command string. TEP_PRINT_NAME, "%s" - Event name. TEP_PRINT_LATENCY, "%s" - Latency of the event. It prints 4 or more fields - interrupt state, scheduling state, current context, and preemption count. Field 1 is the interrupt enabled state: d : Interrupts are disabled . : Interrupts are enabled X : The architecture does not support this information Field 2 is the "need resched" state. N : The task is set to call the scheduler when possible, as another higher priority task may need to be scheduled in. . : The task is not set to call the scheduler. Field 3 is the context state. . : Normal context s : Soft interrupt context h : Hard interrupt context H : Hard interrupt context which triggered during soft interrupt context. z : NMI context Z : NMI context which triggered during hard interrupt context Field 4 is the preemption count. . : The preempt count is zero. On preemptible kernels (where the task can be scheduled out in arbitrary locations while in kernel context), the preempt count, when non zero, will prevent the kernel from scheduling out the current task. The preempt count number is displayed when it is not zero. Depending on the kernel, it may show other fields (lock depth, or migration disabled, which are unique to specialized kernels). TEP_PRINT_TIME, %d - event time stamp. A divisor and precision can be specified as part of this format string: "%precision.divisord". Example: "%3.1000d" - divide the time by 1000 and print the first 3 digits before the dot. Thus, the time stamp "123456000" will be printed as "123.456" TEP_PRINT_INFO, "%s" - event information. TEP_PRINT_INFO_RAW, "%s" - event information, in raw format.
#include <event-parse.h> #include <trace-seq.h> ... struct trace_seq seq; trace_seq_init(&seq); struct tep_handle *tep = tep_alloc(); ... void print_my_event(struct tep_record *record) { trace_seq_reset(&seq); tep_print_event(tep, s, record, "%16s-%-5d [%03d] %s %6.1000d %s %s", TEP_PRINT_COMM, TEP_PRINT_PID, TEP_PRINT_CPU, TEP_PRINT_LATENCY, TEP_PRINT_TIME, TEP_PRINT_NAME, TEP_PRINT_INFO); } ...event-parse.h Header file to include in order to have access to the library APIs.trace-seq.h Header file to include in order to have access to trace sequences related APIs. Trace sequences are used to allow a function to call several other functions to create a string of data to use.-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. | |