# tep_print_event

## NAME



           tep_print_event - Writes event information into a trace sequence.
    


## SYNOPSIS



           **#include <event-parse.h>**
           **#include <trace-seq.h>**
    
           void **tep_print_event**(struct tep_handle *_tep_ , struct trace_seq*_s_ , struct tep_record *_record_ , const char *_fmt_ , _..._)
    


## DESCRIPTION



           The **tep_print_event()** function parses the event information of the
           given _record_ and writes it into the trace sequence _s_ , according to
           the format string _fmt_. The desired information is specified after
           the format string. The _fmt_ 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.
    


## EXAMPLE



               #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);
               }
               ...
    


## FILES



               **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.
    


## LICENSE



           libtraceevent is Free Software licensed under the GNU LGPL 2.1
    


## RESOURCES



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


## NOTES



            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
    


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