How to create a Header File in C Language or In C How to make User Defined Header Files :-
First we have to install or copy Turbo C++ in our computer. If we copy the TC folder, which should be copied into the same Drive as the Source Computer Drive, otherwise an Error will occur see more.
Any way let us guess the C Program in "C:\TC\BIN\TC.EXE"
then usually the Header files residing in "C:\TC\INCLUDE\" directory.
our working directory is "C:\TC\BIN\"
Let us try How to create a "Hello World!" Program with clrscr() SDF :-
#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
printf("Hello World!");
}
in the above program, we used clrscr() as a System Defined Function, because it is defined in conio.h and it is included.
Let us try How to create a "Hello World!" Program with clrscr() as UDF and User Defined Header File :-
Step 1:
fist let us make a header file named "my_header_file.h" and its contents given below
#include<stdio.h>
#include<conio.h>
void clrscr(void)
{
int i;
gotoxy(1,1);
for(i=1;i<=25;i++)
{
printf("\n");
}
gotoxy(1,1);
}
save as in the location mentioned above "C:\TC\INCLUDE\my_header_file.h"
header file creation over
Step 2:
now create our C file named "my_c_file.c"
#include<stdio.h>
#include<my_header_file.h>
main()
{
clrscr();
printf("Hello World!");
}
save as in the location mentioned above "C:\TC\BIN\my_c_file.c"
in the above program, we used clrscr() as a User Defined Function, it is defined in the header file my_header_file.h and it is included instead of conio.h.
Now let us see the real thing. just Run "C:\TC\BIN\my_c_file.c"
output will be:
Hello World!
Note:
1) if we save our header in "C:\TC\INCLUDE\" it should be included as #include<my_header_file.h>
2) if we save our header in "C:\TC\BIN\" it should be included as #include"my_header_file.h"