c - Overloading free() so my program use mine instead of the system's

Question

I need to recode the free() func for educational purpose and it must be named free() also.

When i rename my function myfree() it work flawlessly but when i name it free() the program don't know if he need to use mine or the system's so the program just Segmentation fault(core dumped) even if i don't call my free (just the declaration of another free() func seem to crash it)

so how can i tell the compiler to use mine instead of the system's ?

thanks you in advance.

EDIT : Linux operating system

Answer 1

Basically, you have three options that I can see

• Redirect it during compile time, for example using #define as @Mohamed suggests.
• Change it at runtime using LD_PRELOAD.
• Modify the existing malloc/free using malloc hooks.