标准c头文件

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1995年，Normative Addendum 1 (NA1)批准了三个头文件(iso646.h, wchar.h, and wctype.h)增加到C标准函数库中。C99标准增加了六个头文件(complex.h, fenv.h, inttypes.h, stdbool.h, stdint.h, and tgmath.h)。C11标准中又新增了5个头文件(stdalign.h, stdatomic.h, stdnoreturn.h, threads.h, and uchar.h)。至此，C标准函数库共29个头文件：

名字	源自	描述
<assert.h>		Contains the assert macro, used to assist with detecting logical errors and other types of bug in debugging versions of a program.
<complex.h>	C99	A set of functions for manipulating 复数.
<ctype.h>		Defines set of functions used to classify characters by their types or to convert between upper and lower case in a way that is independent of the used character set (typically ASCII or one of its extensions, although implementations utilizing EBCDIC are also known).
<errno.h>		For testing error codes reported by library functions.
<fenv.h>	C99	Defines a set of functions for controlling 浮点数 environment.
<float.h>		Defines macro constants specifying the implementation-specific properties of the 浮点数 library.
<inttypes.h>	C99	Defines exact width integer types.
<iso646.h>	NA1	Defines several macros that are equivalent to some of the operators in C. For programming in ISO 646variant character sets.
<limits.h>		Defines macro constants specifying the implementation-specific properties of the integer types.
<locale.h>		Defines C localization functions.
<math.h>		Defines C mathematical functions.
<setjmp.h>		Declares the macros setjmp and longjmp, which are used for non-local exits.
<signal.h>		Defines C signal handling functions.
<stdalign.h>	C11	For querying and specifying the data structure alignment of objects.
<stdarg.h>		For accessing a varying number of arguments passed to functions.
<stdatomic.h>	C11	For atomic operations on data shared between threads.
<stdbool.h>	C99	Defines a boolean data type.
<stddef.h>		Defines several useful types and macros.
<stdint.h>	C99	Defines exact width integer types.
<stdio.h>		Defines core input and output functions
<stdlib.h>		Defines numeric conversion functions, pseudo-random numbers generation functions, dynamicmemory allocation, process control functions
<stdnoreturn.h>	C11	For specifying non-returning functions.
<string.h>		Defines C string handling functions.
<tgmath.h>	C99	Defines type-generic mathematical functions.
<threads.h>	C11	Defines functions for managing multiple threads as well as mutexes and condition variables.
<time.h>		Defines date and time handling functions
<uchar.h>	C11	Types and functions for manipulating Unicode characters.
<wchar.h>	NA1	Defines wide string handling functions.
<wctype.h>	NA1	Defines set of functions used to classify wide characters by their types or to convert between upper and lower case