C getopt_long_only Without Alias

Question

I have the following C struct long options

static struct option long_options[] = {
        {"argument1", required_argument, 0,  0 },
        {"argument2", required_argument, 0,  0 },
        {"argument3", required_argument, 0,  0 },
        {0, 0,  0, 0}
};

And i want to use them in this format when i run the program

./program -argument1=1 -argument2=test -argument3=test1 

I don't want ot use the alias of that arguments (if any) for example -a etc. I want to use the full string for that argument like in th example above and take back the value of the argument.

In all examples that i found on the internet they are using the alias of the argument which is only one char

EDIT : Of course the below program is wrong but i want to have in the switch the full argument name not an alias.

while ((opt = getopt_long_only(argc, argv,"", long_options, &long_index )) != -1)
{
    switch (opt) {

        case "argument1":
            printf("\n\n%s",optarg);
         break;

    }
}

How can i do that?

Thanks

Answer 1

To get at the struct option corresponding to the matched argument, use the long_index variable you gave getopt_long() to index into the long_options array. The name string is in there to match.

If what you really want is just a symbolic name for every option then you can just set that in the val field of struct option . That value is returned from the getopt_long() call.

enum {
        OPT_ARGUMENT1 = 1000,
        OPT_ARGUMENT2,
        OPT_ARGUMENT3
};

static struct option long_options[] = {
        {"argument1", required_argument, 0,  OPT_ARGUMENT1 },
        {"argument2", required_argument, 0,  OPT_ARGUMENT2 },
        {"argument3", required_argument, 0,  OPT_ARGUMENT3 },
        {0, 0,  0, 0}
};

It is better to start the value from beyond the ASCII range so as not to clash with short options (which you don't have in this case) or special characters getopt_long() returns.