errorp(3)

NAME
errorp() - determine whether or not a given variable is an error code

SYNOPSIS
int errorp(mixed arg);

DESCRIPTION
Returns 1 if `arg' is an integer that is an error code.

Eventually efuns will be modified to return standard error codes so that code like this will be possible:

 if (errorp(result = efun_call())) printf("error = %d, result);

Will also be a perror(result) efun to return error string that goes with a particular error integer.