Edit my struct in C with pointer - c

Question

I want to create an edit function that receives as a parameter by reference the vector of songs. (using pointers)
The user must choose the song number and re-enter the data of that position of the vector.
I created the struct, I am already receiving the values and I am playing. But I do not know how to edit. Anyone to help me start this part?
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <locale.h>
#include <string.h>
struct registry_of_music {
char name[50];
char artist[60];
char url[80];
};
struct registry_of_music music[9];
int main() {
int i;
printf("\nRegistry of Music\n\n\n");
for(i = 0; i <= 3;i++ ){
printf("Name of Music: ");
fflush(stdin);
fgets(music[i].name, 50, stdin);
printf("Name of Artist: ");
fflush(stdin);
fgets(music[i].artist, 60, stdin);
printf("URL of Internet: ");
fflush(stdin);
fgets(music[i].url, 80, stdin);
}
int op;
do
{
printf("1 - Play\n");
printf("2 - Edit\n");
printf("3 - Exit\n");
printf("Please enter a value:");
scanf("%d", &op);
switch(op) {
case 1: play();
break;
case 2: edit();
break;
case 3: printf("Bye\n");
break;
default: printf("Try Again\n");
}
} while (op!=3);
getch();
return(0);
}
void play(){
int i;
for(i = 0; i <= 3;i++ ){
printf("Name ...........: %s", music[i].name);
printf("Artist .....: %s", music[i].artist);
printf("URL .....: %s", music[i].url);
}
}
void edit(){}

Answer 1

The «fill instance of structure» action is absolutely identical if performing on uninitialized structure or initialized. Even if an instance is not initialized, it has some rubbish values in its fields.
On the other hand there is no way to specify default value which will be shown in fgets's prompt and will be available for keyboard edit, unless you're using much more complicated (and NOT included in ISO C standard) tools.