C Language Header File

C system provides a wealth of system files, called library files, c library files are divided into two categories, one is the extension ". h" file, called the header file, in the previous contains the command we have used many times. The ". h" file contains information such as constant definitions, type definitions, macro definitions, function prototypes, and various compilation selection settings. The other is the function library, including the various functions of the target code for the user to call in the program. Typically, when you call a library function in a program, you include the ". h" file where the function prototype resides before the call.
The full ". h" file for Turbo C is given below.
Turbo C Header File
? ALLOC. H describes memory management functions (allocation, deallocation, and so on).
? Assert. H defines the Assert debug macro.
? Bios. H describes each function that invokes the IBM-PC ROM BIOS subroutine.
? Conio. H describes each function that invokes the DOS console I/O subroutine.
? CTYPE. H contains information about the classification and conversion of characters (such as Isalpha and TOASCII, etc.).
? DIR. H contains structures, macro definitions, and functions for directories and paths.
? Dos. H defines and describes some constants and functions called by Msdos and 8086.
? Erron. H defines the mnemonic for the error code.
? Fcntl. H defines the symbolic constants when connected to the open Library subroutine.
? FLOAT. H contains some parameters and functions for floating-point operations.
? GRAPHICS. H describes the functions of the graphical function, the constant definition of the graphical error code, the various color values of the different drivers, and some special structures used in the function.
? Io. H contains the structure and description of low-level I/O subroutines.
? LIMIT. H contains information such as the environment parameters, compilation time limit, the range of the number.
? MATH. H describes the mathematical operation function, and also the HUGE VAL macro, which illustrates the special structure used by Matherr and Matherr subroutines.
? Mem. H describes some memory manipulation functions (most of which are also described in STRING.H).
? PROCESS. H describes the various functions of process management, spawn ... and exec ... The structure description of the function.
? SETJMP. H defines the types of jmp buf used by the longjmp and setjmp functions to illustrate these two functions.
? SHARE. H defines the parameters of the file share function.
? SIGNAL. H defines Sig[zz (z] [zz)]ign and Sig[zz (z] [zz)]DFL constants, stating RAJSE and signal two functions.
? Stdarg. H defines a macro that reads the function parameter table. (such as the Vprintf,vscarf function).
? Stddef. H defines some common data types and macros.
? STDIO. H defines the standard and extended types and macros defined by Kernighan and Ritchie in Unix System V. Also defines standard I/O pre-defined streams: Stdin,stdout and stderr, which describe I/O stream subroutines.
? STDLIB. H describes some of the commonly used subroutines: conversion subroutines, search/Sort subroutines, and so on.
? STRING. H describes some string operations and memory manipulation functions.
? Sys\stat. H defines some of the symbolic constants that are used when opening and creating files.
? Sys\types. H describes the Ftime function and the TIMEB structure.
? Sys\time. H defines the type of time Time[zz (Z] [ZZ)]t.
? Time. H defines the structure of the time-conversion subroutine Asctime, localtime, and gmtime, the types used for CTime, Difftime, Gmtime, localtime, and Stime, and provides prototypes of these functions.
? VALUE. H defines some important constants, including those that depend on machine hardware and some constants that are described for compatibility with Unix System V, including the range of floating-point and double-precision values.

C Language Header File