Library header files in C programming with meaning are listed below. You can use the following header files by including the header files in the program using #include.

Standard Library Header Files

Libraries	Meaning
<assert.h>	Conditionally compiled macro that compares its argument to zero.
<complex.h>	Complex number arithmetic.
<ctype.h>	Functions to determine the type contained in character data.
<errno.h>	Macros reporting error conditions.
<fenv.h>	Floating-point environment.
<float.h>	Limits of float types.
<inttypes.h>	Format conversion of integer types.
<iso646.h>	Alternative operator spellings.
<limits.h>	Sizes of basic types.
<locale.h>	Localization utilities.
<math.h>	Common mathematics functions.
<setjmp.h>	Nonlocal jumps.
<signal.h>	Signal handling.
<stdalign.h>	alignas and alignof convenience macros.
<stdarg.h>	Variable arguments.
<stdatomic.h>	Atomic types.
<stdbool.h>	Boolean type.
<stddef.h>	Common macro definitions.
<stdint.h>	Fixed-width integer types.
<stdio.h>	Input/output.
<stdlib.h>	General utilities: memory management, program utilities, string conversions, random numbers.
<stdnoreturn.h>	noreturn convenience macros.
<string.h>	String handling.
<tgmath.h>	Type-generic math (macros wrapping math.h and complex.h).
<threads.h>	Thread library.
<time.h>	Time/date utilities.
<uchar.h>	UTF-16 and UTF-32 character utilities.
<wchar.h>	Extended multibyte and wide character utilities.
<wctype.h>	Wide character classification and mapping utilities.
<alloc.h>	Memory management functions.
<assert.h>	Assertion macros.
<bcd.h>	bcd and bcd math functions.
<bios.h>	Bios functions like inpotrb, outportb, etc.
<complex.h>	Math functions for complex numbers.
<conio.h>	MS-DOS Console IO Functions.
<ctype.h>	Character Conversion Macros and Functions.
<dir.h>	Directory and Path information Struct, Macros and functions.
<dirent.h>	POSIX Directory functions.
<dos.h>	MS-DOS and 8086 specific functions.
<errno.h>	Error Code Definitions.
<fcntl.h>	Defines constants used in library function open.
<float.h>	Functions related to floating-point number.
<generic.h>	Contains macros for generic class declarations.
<graphics.h>	All graphics related functions are declared here.
<io.h>	Contains structures and declarations for low-level input/output routines.
<limits.h>	Contains environmental parameters and compile-time limitations.
<locale.h>	Declares language-specific information.
<malloc.h>	Memory management functions.
<math.h>	Declares prototypes for the math functions
<mem.h>	Declares the memory-manipulation functions.
<memory.h>	Memory manipulation functions.
<new.h>	Access to operator new and newhandler.
<process.h>	Contains declarations for the spawn... and exec... functions.
<search.h>	Declares functions for searching and sorting.
<setjmp.h>	Defines a type used by longjmp and setjmp.
<share.h>	Defines parameters used in functions that use file-sharing.
<signal.h>	Defines constants and declarations for signal and raise.
<stdarg.h>	Used to parse the variable number of arguments.
<stddef.h>	Defines several common data types and macros.
<stdio.h>	Defines types and macros needed for the Standard I/O rountines and stream-level I/O routines.
<stdlib.h>	Standard Library functions including conversion and search/sort routines.
<string.h>	Declares several string and memory manipulation routines.
<sys\locking.h>	Definitions for mode parameter of locking function.
<sys\stat.h>	Defines symbolic constants used for opening and creating files.
<sys\timeb.h>	Declares the function ftime and the structure timeb that ftime returns.
<sys\types.h>	Declares the type time_t used with time functions.
<time.h>	Defines a structure filled in by the time-conversion routines.
<utime.h>	Declares the functions utime and the structure utimbuf.
<values.h>	Defines important constants, including machine dependencies.
<varargs.h>	Defines old style marcos for processing variable argumnet lists. Superceded by 'stdarg.h'.

Previous Next