ref: ae0d87a19f53e5e8690e4a41536b5a825a3d9787
dir: /include/bits/linux/sys.h/
#define O_RDONLY 0x00000000 #define O_WRONLY 0x00000001 #define O_RDWR 0x00000002 #define O_TRUNC 0x00000200 #define O_APPEND 0x00000400 #define O_CREAT 0x00000040 typedef int pid_t; struct sigaction { void (*sa_handler)(int); int sa_mask; int sa_flags; }; extern pid_t _getpid(void); extern int _kill(pid_t, int); extern int _sigaction(int, struct sigaction *, struct sigaction *);