#include "nortlib.h"
int (*nl_error)(unsigned int level, char *s, ...);
int nl_err(int level, char *s, ...);
nl_error() is a retargettable standard error message function. It is actually a function pointer which may be modified either statically or dynamically as the application requires.
nl_error() functions provide standard printf-style formatting for status messages. The level argument determines how the message is handled:
Debug messages normally do not appear, but you can adjust the debug level to see some or all of your debugging messages. For the default functions nl_err() and nl_verror(), the current debug level is stored in the variable nl_debug_level, which may be adjustable by command line flags. For msg(), the debug level is controlled via the -l flag and does not use nl_debug_level.
The nortlib library provides a default function, nl_err(), which reports warnings to stderr and normal messages to stdout. The default function is included in the same module with the default definition of the nl_error pointer. In order to override the default, you must include your own definition of nl_error and initialize it to point to your own function.
This is done automatically for programs developed using the ARP Data Acquisition Systems architecture, where nl_error is mapped to the msg() function, which routes messages to a central memo utility. nl_error is also retargetted for many of our compilers to a function which prints out the current input file name and line number. It is then dynamically remapped to the default when input processing is completed. RTG and other QNX Windows-based programs remap nl_error to a function which pops up a window.
The point here is that library functions can count on calling a standard error message routine, and their messages will be mapped to the correct output processor depending on the application they are linked into.
For non-fatal errors, returns the error level code.
nl_response, nl_verror().