解析带有多个参数的命令行选项[getopt?]

本文介绍了解析带有多个参数的命令行选项[getopt?]的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我需要我的程序从命令行获取多个参数，语法如下:

I need my program to get several arguments from command line, the syntax is as follows:

getpwd -l user1 user2 ... -L -X -S...

因此，我需要将用户吸引到-l选项的后面.我尝试使用getopt，但运气不佳，仅当将其他选项放在-l之前时，它才起作用:

So, I need to get the users behind the -l option. I tried using getopt, but without much luck, it only works when I place the other options before the -l:

getpwd -L -X -S ... -l user1 user2 ...

我的代码(用于-l和-S):

while((c = getopt(argc, argv, "l:S")) != -1){ switch(c){ case 'l': index = optind-1; while(index < argc){ next = strdup(argv[index]); /* get login */ index++; if(next[0] != '-'){ /* check if optarg is next switch */ login[lcount++] = next; } else break; } break; case 'S': sflag++; /* other option */ break; case ':': /* error - missing operand */ fprintf(stderr, "Option -%c requires an operand\n", optopt); break; case '?': /* error - unknown option */ fprintf(stderr,"Unrecognized option: -%c\n", optopt); break; } }

optopt和optind是extern int.

因此，问题是:我可以使用getopt()函数(或getopt_long())吗?还是我必须编写自己的解析器才能获得所需的内容?

So, the question is: Can I use the getopt() function (or getopt_long()) ? Or do I have to write my own parser to get what I need ?

推荐答案

您的代码实际上非常非常接近工作.您唯一缺少的是getopt仅希望您在-l之后使用一个参数，因此会在-l的第一个参数之后继续命令行解析.由于要退后一步并提取更多参数，因此必须告诉getopt从哪里开始重新解析命令行.

Your code was actually very, very close to working. The only thing you were missing is that getopt only expects you to consume one argument after -l, and therefore continues command line parsing following the first argument to -l. Since you're going behind its back and pulling off more arguments, you have to tell getopt where to start parsing the command line again.

getopt将该信息存储在全局变量optind中.当我添加该行时:

getopt stores that information in the global variable optind. When I added the line:

optind = index - 1;

在l情况下的break;之前，您的代码开始工作.

before the break; in your l case, your code started working.