将一个字符串复制到另一个

Question

I have a problem passing text to structure member. Here is my code

#include <stdio.h>
#include <string.h>


typedef struct {
    char *name;
    int rank;
    int weapons;

}player;

player create_player(char name[], int rank, int weapons);
void display_player(player data);

int main (int argc, const char * argv[])
{
    player tmp = create_player("First", 3, 3);
    display_player(tmp);
}

player create_player(char name[], int rank, int weapons)
{
    player newobj;
    char *tmp = malloc(strlen(name) + 1);

    strcpy(newobj.name, tmp);
    newobj.rank = rank;
    newobj.weapons = weapons;
    free(tmp);
    return newobj;
}

void display_player(player data)
{
    printf("Player name %s\n", data.name);
    printf("Player rang %d\n", data.rank);
    printf("Player weapons %d", data.weapons);
}

And here is the output

Player name 
Player rang 3
Player weapons 3

As you can see the result of "Player name" is empty. Also can you give me more elegant way to asign text to newobj.name ? What I miss ?

Answer 1

The strcpy in your code is wrong (it copies uninitialized data into unallocated memory). You probably want:

newobj.name = malloc(strlen(name) + 1);
strcpy(newobj.name, name);

Or more simply, if you have strdup :

newobj.name = strdup(name);