/* Written by Walter Bright, Christopher E. Miller, and many others.
 * www.digitalmars.com
 * Placed into public domain.
 * Linux(R) is the registered trademark of Linus Torvalds in the U.S. and other
 * countries.
 */

module std.c.linux.linux;

public import std.c.linux.linuxextern;
public import std.c.linux.pthread;

private import std.c.stdio;

alias int pid_t;
alias int off_t;
alias uint mode_t;

alias uint uid_t;
alias uint gid_t;

static if (size_t.sizeof == 4)
    alias int ssize_t;
else
    alias long ssize_t;

enum : int
{
	SIGHUP = 1,
	SIGINT = 2,
	SIGQUIT = 3,
	SIGILL = 4,
	SIGTRAP = 5,
	SIGABRT = 6,
	SIGIOT = 6,
	SIGBUS = 7,
	SIGFPE = 8,
	SIGKILL = 9,
	SIGUSR1 = 10,
	SIGSEGV = 11,
	SIGUSR2 = 12,
	SIGPIPE = 13,
	SIGALRM = 14,
	SIGTERM = 15,
	SIGSTKFLT = 16,
	SIGCHLD = 17,
	SIGCONT = 18,
	SIGSTOP = 19,
	SIGTSTP = 20,
	SIGTTIN = 21,
	SIGTTOU = 22,
	SIGURG = 23,
	SIGXCPU = 24,
	SIGXFSZ = 25,
	SIGVTALRM = 26,
	SIGPROF = 27,
	SIGWINCH = 28,
	SIGPOLL = 29,
	SIGIO = 29,
	SIGPWR = 30,
	SIGSYS = 31,
	SIGUNUSED = 31,
}

enum
{
    O_RDONLY = 0,
    O_WRONLY = 1,
    O_RDWR = 2,
    O_CREAT = 0100,
    O_EXCL = 0200,
    O_TRUNC = 01000,
    O_APPEND = 02000,
}

struct struct_stat	// distinguish it from the stat() function
{
    ulong st_dev;	/// device
    ushort __pad1;
    uint st_ino;	/// file serial number
    uint st_mode;	/// file mode
    uint st_nlink;	/// link count
    uint st_uid;	/// user ID of file's owner
    uint st_gid;	/// user ID of group's owner
    ulong st_rdev;	/// if device then device number
    ushort __pad2;
    int st_size;	/// file size in bytes
    int st_blksize;	/// optimal I/O block size
    int st_blocks;	/// number of allocated 512 byte blocks
    int st_atime;
    uint st_atimensec;
    int st_mtime;
    uint st_mtimensec;
    int st_ctime;
    uint st_ctimensec;

    uint __unused4;
    uint __unused5;
}

unittest
{
    assert(struct_stat.sizeof == 88);
}

enum : int
{
    S_IFIFO  = 0010000,
    S_IFCHR  = 0020000,
    S_IFDIR  = 0040000,
    S_IFBLK  = 0060000,
    S_IFREG  = 0100000,
    S_IFLNK  = 0120000,
    S_IFSOCK = 0140000,

    S_IFMT   = 0170000,

    S_IREAD  = 0000400,
    S_IWRITE = 0000200,
    S_IEXEC  = 0000100,
}

extern (C)
{
    int access(in char*, int);
    int open(in char*, int, ...);
    int read(int, void*, int);
    int write(int, in void*, int);
    int close(int);
    int lseek(int, int, int);
    int fstat(int, struct_stat*);
    int lstat(in char*, struct_stat*);
    int stat(in char*, struct_stat*);
    int chdir(in char*);
    int mkdir(in char*, int);
    int rmdir(in char*);
    char* getcwd(char*, int);
    int chmod(in char*, mode_t);
    int fork();
    int dup(int);
    int dup2(int, int);
    int pipe(int[2]);
    pid_t wait(int*);
    int waitpid(pid_t, int*, int);

    uint alarm(uint);
    char* basename(char*);
    //wint_t btowc(int);
    int chown(in char*, uid_t, gid_t);
    int chroot(in char*);
    size_t confstr(int, char*, size_t);
    int creat(in char*, mode_t);
    char* ctermid(char*);
    int dirfd(DIR*);
    char* dirname(char*);
    int fattach(int, char*);
    int fchmod(int, mode_t);
    int fdatasync(int);
    int ffs(int);
    int fmtmsg(int, char*, int, char*, char*, char*);
    int fpathconf(int, int);
    int fseeko(FILE*, off_t, int);
    off_t ftello(FILE*);

    extern char** environ;
}

struct timeval
{
    int tv_sec;
    int tv_usec;
}

struct struct_timezone
{
    int tz_minuteswest;
    int tz_dstime;
}

struct tm
{
    int tm_sec;
    int tm_min;
    int tm_hour;
    int tm_mday;
    int tm_mon;
    int tm_year;
    int tm_wday;
    int tm_yday;
    int tm_isdst;
    int tm_gmtoff;
    int tm_zone;
}

extern (C)
{
    int utimes(const char *path, timeval* times);
    
    int gettimeofday(timeval*, struct_timezone*);
    int settimeofday(in timeval*, in struct_timezone*);
    __time_t time(__time_t*);
    char* asctime(in tm*);
    char* ctime(in __time_t*);
    tm* gmtime(in __time_t*);
    tm* localtime(in __time_t*);
    __time_t mktime(tm*);
    char* asctime_r(in tm* t, char* buf);
    char* ctime_r(in __time_t* timep, char* buf);
    tm* gmtime_r(in __time_t* timep, tm* result);
    tm* localtime_r(in __time_t* timep, tm* result);
}

/**************************************************************/
// Memory mapping from <sys/mman.h> and <bits/mman.h>

enum
{
	PROT_NONE	= 0,
	PROT_READ	= 1,
	PROT_WRITE	= 2,
	PROT_EXEC	= 4,
}

// Memory mapping sharing types

enum
{	MAP_SHARED	= 1,
	MAP_PRIVATE	= 2,
	MAP_TYPE	= 0x0F,
	MAP_FIXED	= 0x10,
	MAP_FILE	= 0,
	MAP_ANONYMOUS	= 0x20,
	MAP_ANON	= 0x20,
	MAP_GROWSDOWN	= 0x100,
	MAP_DENYWRITE	= 0x800,
	MAP_EXECUTABLE	= 0x1000,
	MAP_LOCKED	= 0x2000,
	MAP_NORESERVE	= 0x4000,
	MAP_POPULATE	= 0x8000,
	MAP_NONBLOCK	= 0x10000,
}

// Values for msync()

enum
{	MS_ASYNC	= 1,
	MS_INVALIDATE	= 2,
	MS_SYNC		= 4,
}

// Values for mlockall()

enum
{
	MCL_CURRENT	= 1,
	MCL_FUTURE	= 2,
}

// Values for mremap()

enum
{
	MREMAP_MAYMOVE	= 1,
}

// Values for madvise

enum
{	MADV_NORMAL	= 0,
	MADV_RANDOM	= 1,
	MADV_SEQUENTIAL	= 2,
	MADV_WILLNEED	= 3,
	MADV_DONTNEED	= 4,
}

extern (C)
{
void* mmap(void*, size_t, int, int, int, off_t);
const void* MAP_FAILED = cast(void*)-1;

int munmap(void*, size_t);
int mprotect(void*, size_t, int);
int msync(void*, size_t, int);
int madvise(void*, size_t, int);
int mlock(void*, size_t);
int munlock(void*, size_t);
int mlockall(int);
int munlockall();
void* mremap(void*, size_t, size_t, int);
int mincore(void*, size_t, ubyte*);
int remap_file_pages(void*, size_t, int, size_t, int);
int shm_open(in char*, int, int);
int shm_unlink(in char*);
}

extern(C)
{

    enum
    {
	DT_UNKNOWN = 0,
	DT_FIFO = 1,
	DT_CHR = 2,
	DT_DIR = 4,
	DT_BLK = 6,
	DT_REG = 8,
	DT_LNK = 10,
	DT_SOCK = 12,
	DT_WHT = 14,
    }

    struct dirent
    {
	uint d_ino;		// this is int on some linuxes
	off_t d_off;
	ushort d_reclen;
	ubyte d_type;		// this field isn't there on some linuxes
	char[256] d_name;
    }

    struct dirent64
    {
	ulong d_ino;
	long d_off;
	ushort d_reclen;
	ubyte d_type;
	char[256] d_name;
    }

    struct DIR
    {
	// Managed by OS.
    }
    
    DIR* opendir(in char* name);
    int closedir(DIR* dir);
    dirent* readdir(DIR* dir);
    void rewinddir(DIR* dir);
    off_t telldir(DIR* dir);
    void seekdir(DIR* dir, off_t offset);
}


extern(C)
{
	private import std.intrinsic;
	
	
	int select(int nfds, fd_set* readfds, fd_set* writefds, fd_set* errorfds, timeval* timeout);
	int fcntl(int s, int f, ...);
	
	
	enum
	{
		EINTR = 4,
		EINPROGRESS = 115,
	}
	
	
	const uint FD_SETSIZE = 1024;
	//const uint NFDBITS = 8 * int.sizeof; // DMD 0.110: 8 * (int).sizeof is not an expression
	const int NFDBITS = 32;
	
	
	struct fd_set
	{
		int[FD_SETSIZE / NFDBITS] fds_bits;
		alias fds_bits __fds_bits;
	}
	
	
	int FDELT(int d)
	{
		return d / NFDBITS;
	}
	
	
	int FDMASK(int d)
	{
		return 1 << (d % NFDBITS);
	}
	
	
	// Removes.
	void FD_CLR(int fd, fd_set* set)
	{
		btr(cast(uint*)&set.fds_bits.ptr[FDELT(fd)], cast(uint)(fd % NFDBITS));
	}
	
	
	// Tests.
	int FD_ISSET(int fd, fd_set* set)
	{
		return bt(cast(uint*)&set.fds_bits.ptr[FDELT(fd)], cast(uint)(fd % NFDBITS));
	}
	
	
	// Adds.
	void FD_SET(int fd, fd_set* set)
	{
		bts(cast(uint*)&set.fds_bits.ptr[FDELT(fd)], cast(uint)(fd % NFDBITS));
	}
	
	
	// Resets to zero.
	void FD_ZERO(fd_set* set)
	{
		set.fds_bits[] = 0;
	}
}

extern (C)
{
    /* From <dlfcn.h>
     * See http://www.opengroup.org/onlinepubs/007908799/xsh/dlsym.html
     */

    const int RTLD_NOW = 0x00002;	// Correct for Red Hat 8

    void* dlopen(in char* file, int mode);
    int   dlclose(void* handle);
    void* dlsym(void* handle, in char* name);
    char* dlerror();
}

extern (C)
{
    /* from <pwd.h>
     */

    struct passwd
    {
	char *pw_name;
	char *pw_passwd;
	uid_t pw_uid;
	gid_t pw_gid;
	char *pw_gecos;
	char *pw_dir;
	char *pw_shell;
    }

    enum _SIGSET_NWORDS = 1024 / (8 * uint.sizeof);
    struct sigset_t
    {
	uint[_SIGSET_NWORDS] __val;
    }

    int getpwnam_r(const(char)*, passwd*, void*, size_t, passwd**);
    passwd* getpwnam(in char*);
    passwd* getpwuid(uid_t);
    int getpwuid_r(uid_t, passwd*, char*, size_t, passwd**);
    int kill(pid_t, int);
    int sem_close(sem_t*);
    int sigemptyset(sigset_t*);
    int sigfillset(sigset_t*);
    int sigismember(sigset_t*, int);
    int sigsuspend(sigset_t*);
}

extern (C)
{
    /* from semaphore.h
     */

    struct sem_t
    {
        _pthread_fastlock __sem_lock;
        int __sem_value;
        void* __sem_waiting;
    }

    int sem_init(sem_t*, int, uint);
    int sem_wait(sem_t*);
    int sem_trywait(sem_t*);
    int sem_post(sem_t*);
    int sem_getvalue(sem_t*, int*);
    int sem_destroy(sem_t*);
}

extern (C)
{
    /* from utime.h
     */

    struct utimbuf
    {
	__time_t actime;
	__time_t modtime;
    }

    int utime(const char* filename, utimbuf* buf);
}

extern (C)
{
    /* from unistd.h
     */

    gid_t getgid();
    uid_t getuid();
    int setpgid(pid_t pid, pid_t pgid);
    pid_t getpgid(pid_t pid);
    int setpgrp();
    pid_t getpgrp();

}

extern (C)
{
    /* from signal.h
     */

    int killpg(pid_t, int);
}