About GNU C Library

Any Unix-like operating system needs a C library: the library which defines the ``system calls'' and other basic facilities such as open, malloc, printf, exit...

The GNU C library is used as the C library in the GNU system and most systems with the Linux kernel.

The history of Unix and various standards determine much of the interface of the C library. In general the GNU C library supports the ISO C and POSIX standards. We also try to support the features of popular Unix variants (including BSD and System V) when those do not conflict with the standards. Different compatibility modes (selectable when you compile an application) allow the peaceful coexistence of compatibility support for different varieties of Unix.

It includes below items

 （1）string
 （2）signal
 （3）dlfcn(share library dynamic load management)
 （4）direc
 （5）elf(interpreter)
 （6）iconv
 （7）inet
 （8）intl
 （9）io
 （10）linuxthreads
 （11）locale
 （12）login
 （13）malloc
 （14）nis
 （15）stdlib