Lunix环境下用main函数的参数实现一个简易参数

#include<stdio.h>

int sub(int a,int b)
{
return a-b;
}

int mydiv(int a,int b)
{
if(0==b)
{
printf("the divsor is zero!\n");
return -1;
}
return a/b;
}

int add(int a,int b)
{
return a+b;
}

int multi(int a,int b)
{
return a*b;
}

void usage(const char*proc)
{
printf("Usage:%s-[a|s|d] data1,data2",proc);
}

int main(int argc,char *argv[])
{
int data1=atoi(argv[2]);
int data2=atoi(argv[3]);
if(argc!=4)
{
usage(argv[0]);
return 1;
}

if(strcmp("-a",argv[1])==0)
{
printf("res:%d\n",add(data1,data2));
}
else if(strcmp("-s",argv[1])==0)
{
printf("res:%d\n",sub(data1,data2));
}
else if(strcmp("-m",argv[1])==0)
{
printf("res: %d\n",multi(data1,data2));
}
else if(strcmp("-d",argv[1])==0)
{
if(mydiv(data1,data2)!=-1)
{
printf("res:%d\n",mydiv(data1,data2));
}
else
{
return -1;
}
}
else
{
usage(argv[0]);
}
return 0；
}