Implementing parsing with the ls command in C-CodePudding

I'm trying to implement the ls command in C with a few parameters like -a, -l... or -la, but I'm having issues with the parsing, when I use the input I get Segmentation Fault, this is an example of the -a parameter:

int comparator(char *av) {
    int i = 0;
    if (my_strcmp((av[i]), "-a") == 0)
        return 0;
    else
        return 1;
}

int my_ls_a(char *path) {
    int comp = comparator(path);
    DIR *pdirec = opendir(".");
    struct dirent *direc;
    direc = readdir(pdirec);
    
    while (direc != NULL || comp == 0) {
        my_printf("%s  ", direc->d_name);
        direc = readdir(pdirec);
    }
    if ((path = readdir(pdirec)) == NULL)
        my_printf("\n");
    if (pdirec == NULL)
        return (84);
    closedir(pdirec);
    return (0);
}

And this is my main:

int main(int ac, char *av[]) {  
    if (ac == 1)
        my_ls_a(av[0]);
    return 0;
}

I already have all the #include in a .h by the way.

When I only use the main function it works but not when I add the parameter -a.

CodePudding user response：

It's probably better to use getopt() for parameter parsing instead of writing your own parser.

CodePudding user response：

You have undefined behavior in the function comparator in my_strcmp((av[i]), "-a") because av is defined as a char * so you are passing a character where my_strcmp probably expects a pointer.

You should compile with -Wall -Werror to avoid such silly mistakes.

It is unclear why you pass only a single argument to my_ls_a. You should pass both ac and the argument array av and iterate on the arguments to parse the options.