msgget(2)                                                         msgget(2)

NAME
     msgget - get identifier of message queue

SYNOPSIS
     #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 are created for key if one of the following applies:

     -  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 apply:

     EACCES   A message queue identifier exists for key, but operation per-
              mission as specified by the low-order 9 bits of msgflg is not
              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 message queue identif-
              iers allowed in the system will be exceeded.

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




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msgget(2)                                                         msgget(2)

RESULT
     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.

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















































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