/*
 * Raspberry Pi support library for the ACK
 * © 2013 David Given
 * This file is redistributable under the terms of the 3-clause BSD license.
 * See the file 'Copying' in the root of the distribution for the full text.
 */

#ifndef _UNISTD_H
#define _UNISTD_H

#include <stddef.h>
#include <time.h>

/* Types */

typedef int pid_t;
typedef int mode_t;

typedef long suseconds_t;

/* Time handling. */

struct timeval
{
	time_t tv_sec;
	suseconds_t tv_usec;
};

struct timezone
{
	int tz_minuteswest;
	int tz_dsttime;
}; /* obsolete, unused */

extern int gettimeofday(struct timeval* tv, struct timezone* tz);
extern int settimeofday(const struct timeval* tv, const struct timezone* tz);

/* Constants for file access (open and friends) */

enum
{
	O_ACCMODE = 0x3,
	
	O_RDONLY = 0,
	O_WRONLY = 1,
	O_RDWR = 2,
	
	O_CREAT = 0100,
	O_TRUNC = 01000,
	O_APPEND = 02000,
	O_NONBLOCK = 04000
};

/* Special variables */

extern char** environ;

/* Implemented system calls */

extern void _exit(int);
extern pid_t getpid(void);
extern void* sbrk(intptr_t increment);
extern int isatty(int d);
extern off_t lseek(int fildes, off_t offset, int whence);
extern int close(int d);
extern int open(const char* path, int access, ...);
extern int creat(const char* path, mode_t mode);
extern int read(int fd, void* buffer, size_t count);
extern int write(int fd, void* buffer, size_t count);

/* Unimplemented system calls (these are just prototypes to let the library
 * compile). */

extern int fcntl(int fd, int op, ...);

/* Signal handling */

typedef int sig_atomic_t;

#define SIG_ERR ((sighandler_t) -1)           /* Error return.  */
#define SIG_DFL ((sighandler_t) 0)            /* Default action.  */
#define SIG_IGN ((sighandler_t) 1)            /* Ignore signal.  */

#define SIGABRT         6       /* Abort (ANSI) */
#define SIGILL          11      /* Illegal instruction */

#define _NSIG           32      /* Biggest signal number + 1
                                   (not including real-time signals).  */
typedef void (*sighandler_t)(int);
extern sighandler_t signal(int signum, sighandler_t handler);
extern int raise(int signum);

/* Select */

typedef uint32_t fd_set;

extern int select(int nfds, fd_set *readfds, fd_set *writefds,
                  fd_set *exceptfds, struct timeval *timeout);

#define FD_ZERO(set) do { *set = 0; } while (0)
#define FD_SET(fd, set) do { *set |= (1<<fd); } while (0);
#define FD_CLR(fd, set) do { *set &= ~(1<<fd); } while (0);
#define FD_ISSET(fd, set) (*set | (1<<fd))

#endif