[Linux] linux解析命令行选项getopt_long用法解读

[cpp] 
#include <getopt.h> //getopt_long()头文件位置 
int getopt_long (int ___argc, char *const *___argv, 
const char *__shortopts, 
const struct option *__longopts, int *__longind); 
int getopt_long_only (int ___argc, char *const *___argv, 
const char *__shortopts, 
const struct option *__longopts, int *__longind);

[cpp] 
struct option 
{ 
const char *name;//长选项名 
int has_arg;//是否需要参数 
int *flag; 
int val; 
};

[cpp] 
# define no_argument 0 //不需要参数 
# define required_argument 1 //必须指定参数 
# define optional_argument 2 //参数可选

[cpp] 
#include <stdio.h> 
#include <stdlib.h> 
#include <getopt.h> //getopt_long()头文件位置 

int main(int argc, char** argv) 
{ 
const char *optstring="n:v"; 
int c,deb,index; 
struct option opts[]={{"username",required_argument,NULL,'n'}, 
{"version",no_argument,NULL,'v'}, 
{"debug",no_argument,&deb,1}, 
{0,0,0,0}}; 
while((c=getopt_long(argc,argv,optstring,opts,&index))!=-1) 
{ 
switch(c) 
{ 
case 'n'://-n 或者 --username 指定用户名 
printf("username is %s\n",optarg); 
break; 
case 'v'://-v 或者--version,输出版本号 
printf("version is 0.0.1 \n"); 
break; 
case 0://flag不为NULL 
printf("debug is %d\n",deb); 
break; 
case '?'://选项未定义 
printf("?\n"); 
break; 
default: 
printf("c is %d\n",c); 
break; 
} 
} 
return 0; 
}