argc argv

int main(int argc,char **argv)

int argc;

char *argv[];

argc 参数个数 最少为1
An integer that contains the count of arguments that follow in argv. The argc parameter is always greater than or equal to 1.

argv 参数列表 第一个参数为环境变量之类的信息
An array of null-terminated strings representing command-line arguments entered by the user of the program. By convention, argv[0] is the command with which the program is invoked, argv[1] is the first command-line argument, and so on, until argv[argc], which is always NULL. See Customizing Command Line Processing for information on suppressing command-line processing.

The first command-line argument is always argv[1] and the last one is argv[argc – 1].