trace_vnlogf()

Updated: October 28, 2024

Insert a user string trace event, using a variable argument list

Synopsis:

#include <sys/neutrino.h>
#include <sys/trace.h>

int trace_vnlogf( int code,
                  int max,
                  const char *fmt,
                  va_list arglist );

Arguments:

code
The event code, which must be in the range from _NTO_TRACE_USERFIRST through _NTO_TRACE_USERLAST.
max
The maximum length of the string to include in the event, in bytes, or 0 for no limit.
fmt
A printf()-style formatting string.
Note: You can't use any floating-point formatting codes or parameters; use a function such as sprintf() to format floating-point data in a temporary buffer, and then pass it to trace_vnlogf() using a %s format.
arglist
A variable argument list of the items required by the fmt string.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The trace_vnlogf() function calls TraceEvent() to insert a user string event of class _NTO_TRACE_USER, and of the type specified by code.

Returns:

The number of bytes written in the log, including the terminating null character, or -1 if an error occurred (errno is set).

Errors:

ENOMEM
Insufficient memory to complete the operation.

Classification:

QNX Neutrino

Safety:  
Cancellation point No
Interrupt handler Refer to TraceEvent()
Signal handler Yes
Thread Yes