ref: ab7058659cd53f5506800d9dab12bf86eeb198df
dir: /src/libc/syscall.h/
extern void *_brk(void *addr); extern int _open(const char *path, int flags, int mode); extern int _close(int fd); extern int _read(int fd, void *buf, size_t n); extern int _write(int fd, void *buf, size_t n); extern int _lseek(int fd, long off, int whence); extern void _Exit(int status); extern int _access(char *path, int mode); extern int _unlink(const char *path);