The abort function cannot return to its caller. Up to 32 functions can be registered. If a program executes more than one call to exit , the behavior is undefined. All functions registered by atexit are called in the reverse order of their registration. All open output streams are flushed, all open streams are closed, and all files created by tmpfile are removed.
Control is returned to the host environment.
Otherwise, an unsuccessful termination status is returned. See your DEC C library routine documentation for a detailed description of this function. A null pointer can be specified to inquire whether a command processor exists. If the argument is a null pointer, the system function returns nonzero if a command processor is available or 0 if one is not available. If the argument is not a null pointer, the return value is the status returned by the command processor or 0 if a command processor is not available.