munmap_chunk(): invalid pointer

Question

I\'ve spotted the error in my program and decided to write a simple one, which would help me understand what\'s going on. Here it is :

#include 
#         


        

Answer 1

In function char * second

 char * word = malloc(sizeof(char) * 10);
 word = "ab";

The second statement word = "ab"; changes word to point away from the allocated memory.You are not copying the string "ab" to the area of heap allocated by malloc.

And to free a memory that is not allocated by malloc or similar functions crashes your program.

Attempting to free an invalid pointer (a pointer to a memory block that was not allocated by calloc, malloc, or realloc) may affect subsequent allocation requests and cause errors.

You should use here strcpy as also suggested by others.