如何清除c中的字符指针数组？

Question

I am trying to implement a basic Unix Shell in C. My program stores the user's commands in an char ** args. Here is my problem :

When I ask the user for a command, ex ls , ls is stored in args[0]. Then I fork a child process and execute the command using execvp. Now the next time the user enters another command, say ls again, its stored at args[1]. So I cant execute this command using execvp.

I don't want to iterate through the array looking for ls or for any other arguements because then the program will execute random arguments.

I need a way to empty my args so that I can rewrite args[1].

int main() {
    pid_t childPro;
    pid_t parentPro;
    int i,r,argCount,status,pipeCount,changeOut;
    char **args;

    while(1) {
        argCount=0; 
        printf("davedShell$ "); 
        args = getln(); 

if(argCount>=1) {
    //Creating a child process through fork 
    childPro =fork (); 

    if(childPro==0){
        printf("Child Process: %d successfully created\n",(int) getpid());
        execvp(args[0],args);  
    }
    else if (childPro == -1) {
        printf("Fork Failed- Exiting"); 
    exit(1); 
    }
    parentPro = wait(&status);
    }

Answer 1

If you understood Getln() you could answer your own question, why not Getln(&args)? where is the memory allocated for args?. allocating memory for args within function and returning a pointer to memory has to be handled correctly other wise you may get pointer to stack or registers depending on target architecture