Hands-On System Programming with Linux

malloc(3) – a quick summary

So, let's summarize the key points regarding usage of the malloc(3) API:

• malloc(3) dynamically (at runtime) allocates memory from the process heap
  • As we shall soon learn, this is not always the case
• The single parameter to malloc(3) is an unsigned integer value—the number of bytes to allocate
• The return value is a pointer to the start of the newly allocated memory chunk on success, or NULL on failure:
  • You must check for the failure case; don't just assume it will succeed
  • malloc(3) always returns a memory region that is aligned on an 8-byte boundary
• The content of the newly allocated memory region is considered to be random
  • You must initialize it before reading from any part of it
• You must free the memory ...