msgget(2)                        UNIX System V                        msgget(2)


NAME
      msgget - get message queue

SYNOPSIS
      #include <sys/types.h>
      #include <sys/ipc.h>
      #include <sys/msg.h>

      int msgget(keyt key, int msgflg);

DESCRIPTION
      msgget returns the message queue identifier associated with key.

      A message queue identifier and associated message queue and data
      structure [see intro(2)] are created for key if one of the following are
      true:

            key is IPCPRIVATE.

            key does not already have a message queue identifier associated
            with it, and (msgflg&IPCCREAT) is true.

      On creation, the data structure associated with the new message queue
      identifier is initialized as follows:

            msgperm.cuid, msgperm.uid, msgperm.cgid, and msgperm.gid are
            set to the effective user ID and effective group ID, respectively,
            of the calling process.

            The low-order 9 bits of msgperm.mode are set to the low-order 9
            bits of msgflg.

            msgqnum, msglspid, msglrpid, msgstime, and msgrtime are set to
            0.

            msgctime is set to the current time.

            msgqbytes is set to the system limit.

      msgget fails if one or more of the following are true:

      EACCES         A message queue identifier exists for key, but operation
                     permission [see intro(2)] as specified by the low-order 9
                     bits of msgflg would not be granted.

      ENOENT         A message queue identifier does not exist for key and
                     (msgflg&IPCCREAT) is false.

      ENOSPC         A message queue identifier is to be created but the
                     system-imposed limit on the maximum number of allowed
                     message queue identifiers system wide would be exceeded.



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msgget(2)                        UNIX System V                        msgget(2)


      EEXIST         A message queue identifier exists for key but
                     (msgflg&IPCCREAT) and (msgflg&IPCEXCL) are both true.

SEE ALSO
      intro(2), msgctl(2), msgop(2), stdipc(3C).

DIAGNOSTICS
      Upon successful completion, a non-negative integer, namely a message
      queue identifier, is returned.  Otherwise, a value of -1 is returned and
      errno is set to indicate the error.












































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