printf/vprintf
FM SDK supports the C standard printf() and vprintf() functions. These functions can be called at any time and accept all standard C99 formatting specifiers.
In FMs, these functions do not print to stdout, but instead send log messages to the syslog system.
Since these are formatting messages for a log rather than stdout, there are two differences from the standard C implementations:
>Each line of output from printf()/vprintf() is prefixed with a log header that includes the FM’s ID.
>Each call to printf will create a new log entry whether there is a terminating newline character on the end of the string or not.
