trace_vnlogf()
QNX SDP8.0C Library ReferenceAPIDeveloper
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
%sformat. - 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:
| Safety: | |
|---|---|
| Cancellation point | No |
| Signal handler | Yes |
| Thread | Yes |
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