Create msg.d

It's POSIX header for <sys/msg.h>
See http://forum.dlang.org/thread/lradkwgmyotmldzhynrc@forum.dlang.org

src/core/sys/posix/sys/msg.d

@@ -0,0 +1,95 @@
+/**
+* D header file for POSIX.
+*
+* Authors:   Neven Miculinić
+* Mostly copied/adapted from 
+* /usr/include/linux/msg.h
+* /usr/include/x86_64-linux-gnu/sys/msg.h
+* constants from headers on Linux Mint x86-64
+* manuals
+*/
+module core.sys.posix.sys.msg;
+
+private import core.sys.posix.sys.ipc;
+public import core.sys.posix.sys.types;
+public import core.stdc.config;
+private import std.conv;
+
+version (Posix):
+extern (C):
+
+
+
+/* Accorind to manual for msgctl this constants these two constants are linux specific.
+/* ipcs ctl commands */
+version(Linux) {	
+	public enum MSG_STAT = 11;
+	public enum MSG_INFO = 12;
+}
+
+/* msgrcv options */
+public enum MSG_NOERROR =    octal!10000;  /* no error if message is too big */
+public enum  MSG_EXCEPT =    octal!20000;  /* recv any msg except of specified type.*/
+public enum    MSG_COPY =    octal!40000;  /* copy (not remove) all queue messages */
+
+/* message buffer for msgsnd and msgrcv calls */
+struct msgbuf {
+	c_long mtype;         /* type of message */
+	char mtext[1];      /* message text */
+};
+
+/* buffer for msgctl calls IPC_INFO, MSG_INFO */
+struct msginfo {
+	int msgpool;
+	int msgmap; 
+	int msgmax; 
+	int msgmnb; 
+	int msgmni; 
+	int msgssz; 
+	int msgtql; 
+	ushort msgseg; 
+};
+
+/** 
+* I have no idea whether this part is correct . 
+* See http://pubs.opengroup.org/onlinepubs/7908799/xsh/sysmsg.h.html
+*/
+alias ushort msgqnum_t;	
+alias ushort msglen_t;
+
+struct msqid_ds {
+	ipc_perm msg_perm;            /* Ownership and permissions */
+	time_t          msg_stime;    /* Time of last msgsnd(2) */
+	time_t          msg_rtime;    /* Time of last msgrcv(2) */
+	time_t          msg_ctime;    /* Time of last change */
+	c_ulong         __msg_cbytes; /* Current number of bytes in queue (nonstandard) */
+	msgqnum_t       msg_qnum;     /* Current number of messages in queue */
+        msglen_t        msg_qbytes;   /* Maximum number of bytes allowed in queue */
+        pid_t           msg_lspid;    /* PID of last msgsnd(2) */
+	pid_t           msg_lrpid;    /* PID of last msgrcv(2) */
+};
+
+/*
+* Scaling factor to compute msgmni:
+* the memory dedicated to msg queues (msgmni * msgmnb) should occupy
+* at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
+* up to 8MB       : msgmni = 16 (MSGMNI)
+* 4 GB            : msgmni = 8K
+* more than 16 GB : msgmni = 32K (IPCMNI)
+*/
+public enum MSG_MEM_SCALE =  32;
+public enum MSGMNI =     16;   /* <= IPCMNI */     /* max # of msg queue identifiers */
+public enum MSGMAX =   8192;   /* <= INT_MAX */   /* max size of message (bytes) */
+public enum MSGMNB =  16384;   /* <= INT_MAX */   /* default max size of a message queue */
+
+/* Message queue control operation.  */  
+int msgctl (int msqid, int cmd, msqid_ds *__buf);
+
+/* Get messages queue.  */
+int msgget ( key_t key, int msgflg );
+
+/* Receive message from message queue. */
+ssize_t msgrcv(int msqid, void *msgp, size_t msgsz, c_long msgtyp, int msgflg);
+
+/* Send message to message queue. */
+int msgsnd ( int msqid, msgbuf *msgp, int msgsz, int msgflg );