C header file
Headers
Each function in the C standard library has its associated header.
The headers are included using #include.
Header Including obtains the Declarations for the standard library functions.
Header list
The following table has the common headers.
| Header | Purpose |
|---|---|
| assert.h | assert() macro |
| ctype.h | Character handling |
| errno.h | Error reporting |
| float.h | implementation-dependent floating-point limits |
| limits.h | dependent limits |
| locale.h | Localization |
| math.h | Math library |
| setjmp.h | Nonlocal jumps |
| signal.h | Signal handling |
| stdarg.h | Variable argument lists |
| stddef.h | Constants |
| stdio.h | I/O system |
| stdlib.h | Miscellaneous declarations |
| string.h | string functions |
| time.h | system time functions |
| complex.h | complex arithmetic. |
| fenv.h | Gives access to the floating-point status flags and other aspects of the floating-point environment. |
| inttypes.h | A standard, portable integer type names. |
| iso646.h | Defines macros that correspond to various operators, such as && and ^. |
| stdbool.h | Supports Boolean data types. Defines the macro bool, which helps with C++ compatibility. |
| stdint.h | Defines a standard, portable set of integer type names. This file is included by inttypes.h. |
| tgmath.h | Defines type-generic floating-point macros. |
| wchar.h | multibyte and wide-character functions. |
| wctype.h | multibyte and wide-character classification functions. |
Example
Use header file to include functions
#include <stdio.h>
//from w w w . ja v a2s .c o m
int main(void)
{
printf("\nBe careful!!\a");
return 0;
}
The code above generates the following result.
