ipcs(1) ipcs(1) NAME ipcs - report status of interprocess communication facilities SYNOPSIS ipcs [-mqs] [-abcopt] [-C corefile] [-N namelist] DESCRIPTION ipcs displays certain information about active interprocess communication facilities. With no options, ipcs displays information in short format for the message queues, shared memory segments, and semaphores that are currently active in the system. Options The following options restrict the display to the corresponding facilities. (none) This is equivalent to -mqs. -m Display information about active shared memory segments. -q Display information about active message queues. -s Display information about active semaphores. The following options add columns of data to the display. See "Column Description" below. (none) Display default columns: for all facilities: T, ID, KEY, MODE, OWNER, GROUP. -a Display all columns, as appropriate. This is equivalent to -bcopt. -b Display largest-allowable-size information: for message queues: QBYTES; for shared memory segments: SEGSZ; for semaphores: NSEMS. -c Display creator's login name and group name: for all facilities: CREATOR, CGROUP. -o Display information on outstanding usage: for message queues: CBYTES, QNUM; for shared memory segments: NATTCH. -p Display process number information: for message queues: LSPID, LRPID; for shared memory segments: CPID, LPID. -t Display time information: for all facilities: CTIME; for message queues: STIME, RTIME; for Hewlett-Packard Company - 1 - HP-UX Release 10.20: July 1996 ipcs(1) ipcs(1) shared memory segments: ATIME, DTIME; for semaphores: OTIME. The following options redefine the sources of information. -C corefile Use file corefile in place of /dev/kmem. -N namelist Use file namelist in place of /stand/vmunix. Column Descriptions The column headings and the meaning of the columns in an ipcs listing are given below. The columns are printed from left to right in the order shown below. T Facility type: m Shared memory segment q Message queue s Semaphore ID The identifier for the facility entry. KEY The key used as an argument to msgget(), semget(), or shmget() to create the facility entry. (Note: The key of a shared memory segment is changed to IPC_PRIVATE when the segment has been removed until all processes attached to the segment detach it.) MODE The facility access modes and flags: The mode consists of 11 characters that are interpreted as follows: The first two characters can be: R A process is waiting on a msgrcv(). S A process is waiting on a msgsnd(). D The associated shared memory segment has been removed. It will disappear when the last process attached to the segment detaches it. C The associated shared memory segment is to be cleared when the first attach is executed. - The corresponding special flag is not set. The next 9 characters are interpreted as three sets of three characters each. The first set refers to the owner's permissions, the next to permissions of others in the group of the facility entry, and the last to all others. Within each set, the first character indicates permission to read, the second character indicates permission to write or alter the facility entry, and Hewlett-Packard Company - 2 - HP-UX Release 10.20: July 1996 ipcs(1) ipcs(1) the last character is currently unused. r Read permission is granted. w Write permission is granted. a Alter permission is granted. - The indicated permission is not granted. OWNER The login name of the owner of the facility entry. GROUP The group name of the group of the owner of the facility entry. CREATOR The login name of the creator of the facility entry. CGROUP The group name of the group of the creator of the facility entry. CBYTES The number of bytes in messages currently outstanding on the associated message queue. QNUM The number of messages currently outstanding on the associated message queue. QBYTES The maximum number of bytes allowed in messages outstanding on the associated message queue. LSPID The process ID of the last process to send a message to the associated message queue. LRPID The process ID of the last process to receive a message from the associated message queue. STIME The time the last msgsnd() message was sent to the associated message queue. RTIME The time the last msgrcv() message was received from the associated message queue. CTIME The time when the associated facility entry was created or changed. NATTCH The number of processes attached to the associated shared memory segment. SEGSZ The size of the associated shared memory segment. CPID The process ID of the creating process of the shared memory segment. LPID The process ID of the last process to attach or detach the shared memory segment. Hewlett-Packard Company - 3 - HP-UX Release 10.20: July 1996 ipcs(1) ipcs(1) ATIME The time the last shmat() attach was completed to the associated shared memory segment. DTIME The time the last shmdt() detach was completed on the associated shared memory segment. NSEMS The number of semaphores in the set associated with the semaphore entry. OTIME The time the last semop() semaphore operation was completed on the set associated with the semaphore entry. WARNINGS ipcs produces only an approximate indication of actual system status because system processes are continually changing while ipcs is acquiring the requested information. Do not rely on the exact field widths and spacing of the output, as these will vary depending on the system, the release of HP-UX, and the data to be displayed. FILES /dev/kmem Kernel virtual memory /etc/group Group names /etc/passwd User names /stand/vmunix System namelist SEE ALSO msgop(2), semop(2), shmop(2). STANDARDS CONFORMANCE ipcs: SVID2, SVID3 Hewlett-Packard Company - 4 - HP-UX Release 10.20: July 1996