c - 通过 getopt 传递一些参数

Question

我想做的是从命令行获取更多参数，并让它们在新的一行上输出每个参数。我怎么能通过保持相同的结构来做到这一点？我还想获得 -f 输出。

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <getopt.h>

int
main(int argc, char *argv[])
{
    int nod1, opt;
    int nsecs, nod2;

   nsecs = 0;
    nod2 = 0;
    nod1 = 0;

    while ((opt = getopt(argc, argv, "nf:")) != -1) {
        switch (opt) {
        case 'n':
            nod1 = 1;
            break;
        case 'f':
            nsecs = atoi(optarg);
            nod2 = 1;
            break;
        default: /* '?' */
            fprintf(stderr, "Usage: %s [-t nsecs] [-n] name\n",
                    argv[0]);
            exit(EXIT_FAILURE);
        }
    }

   printf("nod1=%d; nod2=%d; optind=%d\n", nod1, nod2, optind);

   if (optind >= argc) {
        fprintf(stderr, "Expected argument after options\n");
        exit(EXIT_FAILURE);
    }

   printf("Output = %s\n", argv[optind]);

   /* Other code omitted */

   exit(EXIT_SUCCESS);
}

来自评论:

The arguments after the -f should be optional and I want to list every single one that has been passed under one another...

$ ./partitioner -n 4 -f Test1 Test2 Test3 Test4
Number:4
File names:
Output = Test1
Output = Test2
Output = Test3
Output = Test4
$

Answer 1

考虑到 Jonathan Leffler 的评论，我编辑了我的答案:

POSIX getopt() doesn't really handle optional arguments sensibly. GNU getopt() is a bit better, but not by much. Avoid them whenever you can.

我提出了一个简单的想法，但可以解决您的问题，所以这里是:

在 argv 中，您有一个按它们在推荐行中排序的参数列表，对吗？因此，如果您可以在 argv 中找到任何 -f，这意味着 -f 之后的所有参数，直到另一个选项或参数列表的末尾您要打印的选项。

从 -f 到另一个选项(在本例中为 -g):

./command -a A -b B -f one two tree -g G

从-f到结束

./command -a A -b B -f one two tree

这里有一个辅助函数可以做到这一点:

bool get_f_args(int argc, char *argv[], int &count, int* indexes)
{
    bool f_found = false, parsing_f_args = false;
    int collect_count = 0;

    if (argc < 3) return false;  // "./command -f" are just two values for argv
                                 // we need at least 3.

    // Check for every argument in the argument list.
    for (int i = 1; i < argc; i++)
    {

        // If you found another option
        // stop collecting args.
        if (argv[i][0] == '-' && parsing_f_args)   // options starts with '-' character.
            parsing_f_args = false;

        if (parsing_f_args)
            indexes[count++] = i;

        // If some is "-f" then the following are the 
        // ones you're looking for. We check for -f after
        //
        // indexes[count++] = i; 
        //
        // in roder to avoid adding -f index to indexes.
        if (strcmp("-f", argv[i]) == 0) { 
            parsing_f_args = true;
            f_found = true;
        }

    }
    return f_found;
}

这是一个使用示例:

int main(int argc, char* argv[])
{
    int count = 0; 
    int indexes[10];

    bool f_found = get_f_args(argc, argv, count, indexes);
    if (f_found){
        for (int i = 0; i < count; i++)
            printf("Ouput = %s\n", argv[indexes[i]]);
    }

    return 0;
}