NAME
pipcs — report status of POSIX interprocess communication facilities
SYNOPSIS
pipcs
[-q
[-P|-T] [-N
qname]]
[-s]
[-abo]
DESCRIPTION
pipcs
displays certain information
on active POSIX interprocess communication facilities.
When no options are specified,
pipcs
displays information in short format for the POSIX message queues
and POSIX named semaphores that are currently active in the system.
Options
The following options restrict the display to the corresponding facilities.
- (none)
This is equivalent to
-qs.
- -N qname
Display details for the POSIX message queue specified
in the
qname
argument.
- -P
Display the list of processes and users using the
POSIX message queues.
- -q
Display information on active POSIX message queues.
- -s
Display information on active POSIX named semaphores.
- -T
Display the creation time and last modification time of
the POSIX message queues.
The options,
-N,
-P,
and
-T
can be used only with the
-q
option.
The options
-P
and
-T
are mutually exclusive.
The following options add columns of data to the display.
See "Column Description" below.
- (none)
Display default columns: for all facilities:
T,
MODE,
OWNER,
GROUP,
REFCNT,
NAME.
- -a
Display all columns, as appropriate.
This is equivalent to
-bo.
- -b
Display largest-allowable-size information:
for POSIX message queues:
QBYTES.
- -o
Display information on outstanding usage:
for POSIX message queues:
QNUM,
MNUM;
for POSIX named semaphores:
VAL,
IVAL.
Column Descriptions
The column headings and the meaning of the columns in an
pipcs
listing are given below.
The columns are printed from left to right in the order shown below.
- T
Facility type:
- q
POSIX message queue
- s
POSIX named semaphore
- MODE
The facility access modes and flags.
The mode consists of nine characters that 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 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.
- REFCNT
The reference count value of the facility entry.
Reference count of
the POSIX message queue represents number of simultaneous open for the
associated one.
Similarly reference count of the POSIX named semaphore
represents number of process referencing the associated one.
- NAME
The name of the facility entry.
- QNUM
The number of messages currently outstanding
on the associated POSIX message queue.
- MNUM
The maximum number of messages allowed
on the associated POSIX message queue.
- QBYTES
The maximum number of bytes allowed
in messages outstanding on the associated POSIX message queue.
- VAL
The current value on the associated POSIX named semaphore.
- IVAL
The initial value hold on the associated POSIX named semaphore.
WARNINGS
pipcs
produces only an approximate indication of actual system status
because system processes are continually changing while
pipcs
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.
EXAMPLES
List the processes and users using the POSIX message queues.
Note that "None" is displayed if there are no processes using the
POSIX message queue.
pipcs -qP
/mq/0 :
1234457645 (root)
5433483354 (vts)
/mq/1 : None
/mq/2 :
8344835378 (user1)
List the processes and users using the POSIX message queue
/mq/2.
pipcs -qP -N /mq/2
/mq/2 :
8344835378 (user1)
List the creation time and last modification time of the POSIX message queues.
Ctime denotes creation time and Ltime denotes last modification time.
pipcs -qT
/mq/0 :
Ctime : Mon Feb 4 05:06:40 PST 2006
Ltime : Mon Feb 6 11:06:40 PST 2006
/mq/abcd :
Ctime : Mon Feb 2 03:06:40 PST 2006
Ltime : Mon Feb 5 03:06:40 PST 2006
List the creation time and last modification time of the POSIX message queue
/mq/0.
pipcs -qT -N /mq/0
/mq/0 :
Ctime : Mon Feb 4 05:06:40 PST 2006
Ltime : Mon Feb 6 11:06:40 PST 2006
FILES
- /etc/group
Group names
- /etc/passwd
User names
SEE ALSO
pipcrm(1),
mq_close(2),
mq_open(2),
mq_receive(2),
mq_send(2),
mq_unlink(2),
sem_close(2),
sem_open(2),
sem_post(2),
sem_unlink(2),
sem_wait(2).
Printable version
