cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations sys_mman/shm_open.c -o sys_mman/shm_open -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
sys_mman/shm_open.c:6:7: error: incompatible function pointer types initializing 'int (*)(const char *, int, mode_t)' (aka 'int (*)(const char *, int, unsigned short)') with an expression of type 'int (const char *, int, ...)' [-Wincompatible-function-pointer-types]
    6 | int (*foo)(const char *, int, mode_t) = shm_open;
      |       ^                                 ~~~~~~~~
1 error generated.