Freeing strings in C

Question

If I would write:

char *a=malloc(sizeof(char)*4);
a=\"abc\";
char *b=\"abc\";

do I need to free this memory, or is it done by my system?

Answer 1

Simple answer yes,no. Also your code is buggy.

Concrete answer:

char *a=malloc(sizeof(char)*4);

You allocate memory so you should free it.

a="abc";

This assigns a pointer to a constant string to your char* a, by doing so you loose the pointer to the memory allocated in the first line, you should never free constant strings.

Use strcpy(a,"abc"); instead of a="abc"; to move the string into your allocated memory.