Man page or keyword search:   man All Sections 1 - General Commands 2 - System Calls 3 - Subroutines, Functions 4 - Special Files 5 - File Formats 6 - Games and Screensavers 7 - Macros and Conventions 8 - Maintenence Commands 9 - Kernel Interface New Commands Server 4.4BSD AIX Alpinelinux Archlinux Aros BSDOS BSDi Bifrost CentOS Cygwin Darwin Debian DigitalUNIX DragonFly ElementaryOS Fedora FreeBSD Gentoo GhostBSD HP-UX Haiku Hurd IRIX Inferno JazzOS Kali Knoppix LinuxMint MacOSX Mageia Mandriva Manjaro Minix MirBSD NeXTSTEP NetBSD OPENSTEP OSF1 OpenBSD OpenDarwin OpenIndiana OpenMandriva OpenServer OpenSuSE OpenVMS Oracle PC-BSD Peanut Pidora Plan9 QNX Raspbian RedHat Scientific Slackware SmartOS Solaris SuSE SunOS Syllable Tru64 UNIXv7 Ubuntu Ultrix UnixWare Xenix YellowDog aLinux   9087 pages apropos Keyword Search (all sections) Output format html ascii pdf view pdf save postscript

MSGGET(2)		    BSD System Calls Manual		     MSGGET(2)

NAME
     msgget — get message queue identifier

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/msg.h>

     int
     msgget(key_t key, int msgflg);

DESCRIPTION
     The msgget() system call returns the message queue identifier associated
     with key.	A message queue identifier is a unique integer greater than
     zero.

     A message queue is created if either key is equal to IPC_PRIVATE, or key
     does not have a message queue identifier associated with it and the
     IPC_CREAT bit is set in msgflg.  If both the IPC_CREAT bit and the
     IPC_EXCL bit are set in msgflg, and key has a message queue identifier
     associated with it already, the operation will fail.

     If a new message queue is created, the data structure associated with it
     (the msqid_ds structure, see msgctl(2)) is initialized as follows:

     ·	 msg_perm.cuid and msg_perm.uid are set to the effective uid of the
	 calling process.

     ·	 msg_perm.gid and msg_perm.cgid are set to the effective gid of the
	 calling process.

     ·	 msg_perm.mode is set to the lower 9 bits of msgflg.

     ·	 msg_qnum, msg_lspid, msg_lrpid, msg_rtime, and msg_stime are set to
	 0.

     ·	 msg_qbytes is set to the system wide maximum value for the number of
	 bytes in a queue (MSGMNB).

     ·	 msg_ctime is set to the current time.

RETURN VALUES
     Upon successful completion a positive message queue identifier is
     returned.	Otherwise, -1 is returned and the global variable errno is set
     to indicate the error.

ERRORS
     [EACCES]		A message queue is already associated with key and the
			caller has no permission to access it.

     [EEXIST]		Both IPC_CREAT and IPC_EXCL are set in msgflg, and a
			message queue is already associated with key.

     [ENOSPC]		A new message queue could not be created because the
			system limit for the number of message queues has been
			reached.

     [ENOENT]		IPC_CREAT is not set in msgflg and no message queue
			associated with key was found.

SEE ALSO
     msgctl(2), msgrcv(2), msgsnd(2), ftok(3)

STANDARDS
     The msgget system call conforms to X/Open System Interfaces and Headers
     Issue 5 (“XSH5”).

HISTORY
     Message queues appeared in the first release of AT&T System V UNIX.

BSD				 May 13, 2004				   BSD

                             _         _         _ 
                            | |       | |       | |     
                            | |       | |       | |     
                         __ | | __ __ | | __ __ | | __  
                         \ \| |/ / \ \| |/ / \ \| |/ /  
                          \ \ / /   \ \ / /   \ \ / /   
                           \   /     \   /     \   /    
                            \_/       \_/       \_/ 

Vote for polarhome