软件说明：

A C program can call on a large number of functions from the Dinkum C99 Library, a conforming implementation of the Standard C library, as revised in 1999. These functions perform essential services such as input and output. They also provide efficient implementations of frequently used operations. Numerous macro and type definitions accompany these functions to help you to make better use of the library. Most of the information about the Standard C library can be found in the descriptions of the standard headers that declare or define library entities for the program