1. 首先编写head.h
1 #ifdef _HEAD_H
2 #define _HEAD_H
3 int add(int,int,int);
4 #endif2. 在同级目录下编写head.c
1 #include "head.h"
2 #include
3 int add(int a,int b,int c)
4 {
5 int result = 0;
6 printf("%s","Please enter the number:");
7 scanf("%d %d %d",&a,&b,&c);
8 result = a+b+c;
9 return result;
10 }3. 编写hello.c
1 #include
2 #include "head.h"
3 void main()
4 {
5 int a=3,b=4,c=5,result=0;
6 result=add(a,b,c);
7 printf("The result is %d!",result);
8 }4. 将hello.c与head.c通过gcc命令编译起来
gcc -o cal hello.c head.c5. 执行可执行文件
./cal