Here we are going to create a function for factorial of a the
given number:
Step 1:
First create the definition of the program and save it with name
fact .c
Int factorial(int num)
{
int f=1,I;
For(i=1;i<=num;i++)
{
F=f*I;
}
return (f);
}
Step 2:
Compile “fact.c” file by
using Alt + F9 keys (in turbo C).
step 3:
“fact.obj” file would be created which is the compiled form of
“fact.c” file.
Step 4:
Then for adding your function to the library function type the
code given below:
c:\> tlib math.lib + c:\
fact.obj
+ means adding c:\fact.obj file in the math library.
We can delete this file using – (minus){c:\> tlib math.lib - c:\ fact.obj}.
Step 5:
Create a file “fact.h”
& declare prototype of fact() function like below.
int factorial (int num);
Now fact.h file containing prototype of function “factorial”.
Step 6:
Let us see how to use
our newly added library function in a C program.
# include <stdio.h>
// Including our user defined function.
# include “c:\\factorial.h”
int main ()
{
int f,n;
prinntf(“enter any
number”); //message to the user
scanf(“%d”,&n); //receiving input from user
// calling
function from library
f = factorial (n);
printf
("factorial = %d \n", f);
return 0;
}
