僅用main函式的引數實現一個整數計算器

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>

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

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

	int data1 = atoi(argv[2]);
	int data2 = atoi(argv[3]);

	if (strcmp("-a", argv[1]) == 0){
	 printf("%d + %d = %d\n", data1, data2, data1 + data2);      //-a   執行加法
	}
	else if (strcmp("-s", argv[1]) == 0){
	 printf("%d - %d = %d\n", data1, data2, data1 - data2);     //-s    減法
	}
	else if (strcmp("-m", argv[1]) == 0){
	 printf("%d * %d = %d\n", data1, data2, data1*data2);       //-m   乘法
	}
	else if (strcmp("-d", argv[1]) == 0){
	 if (data2 == 0){
	 printf("div data is zero!!\n");                              //-d     除法
	 return 2;
	 }
	 printf("%d / %d = %d\n", data1, data2, data1 / data2);
	}
	else{
	 usage(argv[0]);                                             //其他
	 return 3;
	}
	return 0;
}


執行結果：

[
 
[email protected] 桌面]$ ./text
Usage: ./text [-a|s|m|d] data1 data2
[[email protected] 桌面]$ ./text -a    20 30
20 + 30 = 50
[[email protected] 桌面]$ ./text -d    20 30
20 / 30 = 0
[[email protected] 桌面]$ ./text -s    20 30
20 - 30 = -10
[[email protected] 桌面]$ ./text -m    20 30
20 * 30 = 600
[[email protected]
 
 桌面]$ ./text -p    20 30
Usage: ./text [-a|s|m|d] data1 data2