These utility functions get and set the current program's name as used by various error-reporting functions.
getprogname() returns the name of the current program. This function is typically useful when generating error messages or other diagnostic output. If the program name has not been set,
getprogname() will return
NULL.
setprogname() sets the name of the current program to be the last pathname component of the
name argument. It should be invoked at the start of the program, using the
argv[0] passed into the program's
main() function. A pointer into the string pointed to by the
name argument is kept as the program name. Therefore, the string pointed to by
name should not be modified during the rest of the program's operation.
A program's name can only be set once, and in
NetBSD that is actually done by program start-up code that is run before
main() is called. Therefore, in
NetBSD, calling
setprogname() from
main() has no effect. However, it does serve to increase the portability of the program: on other operating systems,
getprogname() and
setprogname() may be implemented by a portability library, and a call to
setprogname() allows that library to know the program name without modifications to that system's program start-up code.