GCC 多文件编辑

#include <stdio.h>

int plus(int a, int b);
int minus(int a, int b);
int multiply(int a, int b);
int divide(int a, int b);

#include "calculate.h"

int plus(int a, int b)
{
    int c = a + b;
    return c;
}

int minus(int a, int b)
{
    int c = a - b;
    return c;
}

int multiply(int a, int b)
{
    int c = a * b;
    return c;
}

int divide(int a, int b)
{
    int c = a / b;
    return c;
}

#include "calculate.h"

int main(int argc, char** argv)
{
    int a = 20;
    int b = 10;
    int c = plus(a, b);
    printf("%d
", c);
    c = minus(a, b);
    printf("%d
", c);
    c = multiply(a, b);
    printf("%d
", c);
    c = divide(a, b);
    printf("%d
", c);
    return 0;
}

gcc -Wall main.c calculate.c -o main.o