# SDL_memcmp Compare two buffers of memory. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_stdinc.h) ## Syntax ```c int SDL_memcmp(const void *s1, const void *s2, size_t len); ``` ## Function Parameters | | | | | ------------ | ------- | ---------------------------------------------------- | | const void * | **s1** | the first buffer to compare. NULL is not permitted! | | const void * | **s2** | the second buffer to compare. NULL is not permitted! | | size_t | **len** | the number of bytes to compare between the buffers. | ## Return Value (int) Returns less than zero if s1 is "less than" s2, greater than zero if s1 is "greater than" s2, and zero if the buffers match exactly for `len` bytes. ## Thread Safety It is safe to call this function from any thread. ## Version This function is available since SDL 3.2.0. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryStdinc](CategoryStdinc)