Thre are several other library functions and header files of limited use that we have not included here. Readers should refer to appropriate manuals. Some of the categories are:
Declares integer type errno which will contain the number of an error when it occurs.
Provides facilities to handle exceptional situations such as interrupts or errors.
Provides clock functions as well as date and time functions.
Provides failities to step through a list of function arguments of unknown number and type.
Provides a way of avoiding normal function calls and returns.