atoi()函数
#include<stdio.h>#include<stdlib.h>
int main(int argc,char *argv[])
{
int i,times;
if(argc < 2 || (times = atoi(argv[1])) <1)//为什么是atgv[1],而不是atgv[0]?
printf("Usage:%s positive-number\n",argv[0]);
else
for(i=0;i<times;i++)
puts("Hello,good looking!");
return 0;
}