ref: a6692449e11bf9f40d051e0b8eb566bca72946ca
dir: /src/libc/syscall.h/
extern int _brk(void *); extern void _exit(int); extern int _close(int); extern int _open(const char *, int, int); extern int _read(int, void *, size_t); extern int _unlink(const char *); extern int _write(int, void *, size_t); extern int _access(const char *, int); extern long _lseek(int, long, int);