ipcs(1) DG/UX 5.4R3.00 ipcs(1)
NAME
ipcs - report inter-process communication facilities status
SYNOPSIS
ipcs [ options ]
DESCRIPTION
ipcs prints information about active inter-process communication
facilities. Without options, information is printed in short format
for message queues, shared memory, and semaphores that are currently
active in the system. Otherwise, the information that is displayed
is controlled by the following options:
-q Print information about active message queues.
-m Print information about active shared memory segments.
-s Print information about active semaphores.
If -q, -m, or -s are specified, information about only those
indicated is printed. If none of these three are specified,
information about all three is printed subject to these options:
-b Print information on biggest allowable size: maximum number of
bytes in messages on queue for message queues, size of
segments for shared memory, and number of semaphores in each
set for semaphores. See below for meaning of columns in a
listing.
-c Print creator's login name and group name. See below.
-o Print information on outstanding usage: number of messages on
queue and total number of bytes in messages on queue for
message queues and number of processes attached to shared
memory segments.
-p Print process number information: process ID of last process
to send a message, process ID of last process to receive a
message on message queues, process ID of creating process, and
process ID of last process to attach or detach on shared
memory segments. See below.
-t Print time information: time of the last control operation
that changed the access permissions for all facilities, time
of last msgsnd and last msgrcv on message queues, time of last
shmat and last shmdt on shared memory, time of last semop on
semaphores. See below.
-a Use all print options. (This is a shorthand notation for -b,
-c, -o, -p, and -t.)
The column headings and the meaning of the columns in an ipcs listing
are given below; the letters in parentheses indicate the options that
cause the corresponding heading to appear; ``all'' means that the
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heading always appears. Note that these options only determine what
information is provided for each facility; they do not determine
which facilities are listed.
T (all) Type of the facility:
q message queue
m shared memory segment
s semaphore
ID (all) The identifier for the facility entry.
KEY (all) 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 IPCPRIVATE
when the segment has been removed until all processes
attached to the segment detach it.)
MODE (all) The facility access modes and flags: The mode
consists of 11 characters that are interpreted as
follows. The first two characters are:
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 nine characters are interpreted as three
sets of three bits each. The first set refers to the
owner's permissions; the next to permissions of
others in the user-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 the last character is currently
unused.
The permissions are indicated as follows:
r Read permission is granted.
w Write permission is granted.
a Alter permission is granted.
- The indicated permission is not granted.
OWNER (all) The login name of the owner of the facility entry.
GROUP (all) The group name of the group of the owner of the
facility entry.
CREATOR (a,c) The login name of the creator of the facility entry.
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CGROUP (a,c) The group name of the group of the creator of the
facility entry.
CBYTES (a,o) The number of bytes in messages currently outstanding
on the associated message queue.
QNUM (a,o) The number of messages currently outstanding on the
associated message queue.
QBYTES (a,b) The maximum number of bytes allowed in messages
outstanding on the associated message queue.
LSPID (a,p) The process ID of the last process to send a message
to the associated queue.
LRPID (a,p) The process ID of the last process to receive a
message from the associated queue.
STIME (a,t) The time the last message was sent to the associated
queue.
RTIME (a,t) The time the last message was received from the
associated queue.
CTIME (a,t) The time when the associated entry was created or
changed.
NATTCH (a,o) The number of processes attached to the associated
shared memory segment.
SEGSZ (a,b) The size of the associated shared memory segment.
CPID (a,p) The process ID of the creator of the shared memory
entry.
LPID (a,p) The process ID of the last process to attach or
detach the shared memory segment.
ATIME (a,t) The time the last attach was completed to the
associated shared memory segment.
DTIME (a,t) The time the last detach was completed on the
associated shared memory segment.
NSEMS (a,b) The number of semaphores in the set associated with
the semaphore entry.
OTIME (a,t) The time the last semaphore operation was completed
on the set associated with the semaphore entry.
FILES
/dgux system image (namelist)
/etc/passwd user names
/etc/group group names
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ipcs(1) DG/UX 5.4R3.00 ipcs(1)
SEE ALSO
dgsysinfo(2), semop(2), shmsys(2).
NOTES
Things can change while ipcs is running; the information it gives is
guaranteed to be accurate only when it was retrieved.
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