How to malloc a char[] properly without memory leaks-CodePudding

How do I fix this line to work with my code. I know in C99 variable-length arrays are allowed, but I need to use malloc to fix this line. How would I go about doing that. char stack[strlen(input)]; (I am not using C99, by the way)

CodePudding user response：

Declare stack as pointer and use malloc.

char *stack = malloc(strlen(input));

Don't forget to free the memory.

CodePudding user response：

Allow me to add that it's recommended to always the value of a pointer you just allocated with malloc.

You can do it this way :

char *stack = malloc(strlen(input));
if(stack == NULL){
  return -1;
}

You can modify the -1 with whatever you want depending where you are using this part of code. (-1 being what people usually returns when an error occurs)

Why do that ? malloc function can fail allocating memory space in case RAM is full for example (this doesn't happen often but it has to be catched for code correctness)