尝试返回字符数组引用时出现“错误:冲突类型”[重复]

为了学习C和字符串操作,我正在制作一个小程序,它可以简单地生成随机IP地址作为字符串并输出。根据我从stackoverflow的各种教程和示例中收集到的信息,下面是一种方法,但返回字符数组引用让我感到困惑,因为它无法编译:

#include <stdio.h>
#include <stdlib.h>

int main()
{
  char *testip = randip();
  printf("%s", testip);
  free(testip);
  return 0;
}

// get rand IP
char* randip()
{
  char *ip = malloc(16);
  int a = randint(1,254);
  int b = randint(0,254);
  int c = randint(0,254);
  int d = randint(0,254);

  sprintf(ip, "%d.%d.%d.%d", a, b, c, d);
  printf("D> randip generated %s", ip);
  return ip;
}

// generate rand int
int randint(unsigned int min, unsigned int max)
{
       double scaled = (double)rand()/RAND_MAX;
       return (max - min +1)*scaled + min;
}

test.c: In function ‘main’:
test.c:8:18: warning: initialization makes pointer from integer without a cast [enabled by default]
test.c: At top level:
test.c:17:7: error: conflicting types for ‘randip’
test.c:8:18: note: previous implicit declaration of ‘randip’ was here

我看不出哪些类型不兼容?我是否意外地返回、调用或错误输入了我不想要的类型?

是的,我知道我的随机性不是很随机,也许有更好的方法来处理这一部分,但这超出了这个问题的范围。