ipcs(1) [osx man page]
IPCS(1) BSD General Commands Manual IPCS(1) NAME
ipcs -- report System V interprocess communication facilities status SYNOPSIS
ipcs [-abcMmopQqSsTt] DESCRIPTION
The ipcs utility provides information on System V interprocess communication (IPC) facilities on the system. The options are as follows: -a Show the maximum amount of information possible when displaying active semaphores, message queues, and shared memory segments. (This is shorthand for specifying the -b, -c, -o, -p, and -t options.) -b Show the maximum allowed sizes for active semaphores, message queues, and shared memory segments. The ``maximum allowed size'' is the maximum number of bytes in a message on a message queue, the size of a shared memory segment, or the number of semaphores in a set of semaphores. -c Show the creator's name and group for active semaphores, message queues, and shared memory segments. -M Display system information about shared memory. -m Display information about active shared memory segments. -o Show outstanding usage for active message queues, and shared memory segments. The ``outstanding usage'' is the number of messages in a message queue, or the number of processes attached to a shared memory segment. -p Show the process ID information for active semaphores, message queues, and shared memory segments. The ``process ID information'' is the last process to send a message to or receive a message from a message queue, the process that created a semaphore, or the last process to attach or detach a shared memory segment. -Q Display system information about messages queues. -q Display information about active message queues. -S Display system information about semaphores. -s Display information about active semaphores. -T Display system information about shared memory, message queues and semaphores. -t Show access times for active semaphores, message queues, and shared memory segments. The access times is the time of the last con- trol operation on an IPC object, the last send or receive of a message, the last attach or detach of a shared memory segment, or the last operation on a semaphore. If none of the -M, -m, -Q, -q, -S, or -s options are specified, information about all active IPC facilities is listed. RESTRICTIONS
System data structures may change while ipcs is running; the output of ipcs is not guaranteed to be consistent. BUGS
This manual page is woefully incomplete, because it does not at all attempt to explain the information printed by ipcs. SEE ALSO
ipcrm(1) AUTHORS
Thorsten Lockert <tholo@sigmasoft.com> BSD
June 18, 1994 BSD
Check Out this Related Man Page
ipcs(1) General Commands Manual ipcs(1) NAME
ipcs - report status of interprocess communication facilities SYNOPSIS
core] namelist] DESCRIPTION
displays certain information about active interprocess communication facilities. With no options, 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 Display information about active shared memory segments. Display information about active message queues. 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: Display all columns, as appropriate. This is equivalent to Display largest-allowable-size information: for message queues: for shared memory segments: for semaphores: Display creator's login name and group name: for all facilities: Display information on outstanding usage: for message queues: for shared memory segments: Display process number information: for message queues: for shared memory segments: Display time information: for all facilities: for message queues: for shared memory segments: for semaphores: The following options redefine the sources of information. Use core in place of core can be a core file or a directory created by or Use file namelist or the namelist within core in place of It opens a crash dump for reading. Please refer to cr_open(3) for more details. Column Descriptions The column headings and the meaning of the columns in an listing are given below. The columns are printed from left to right in the order shown below. Facility type: Shared memory segment Message queue Semaphore The identifier for the facility entry. The key used as an argument to or to create the facility entry. (Note: The key of a shared memory segment is changed to when the segment has been removed until all processes attached to the segment detach it.) The facility access modes and flags: The mode consists of 11 characters that are interpreted as follows: The first two characters can be: A process is waiting on a A process is waiting on a The associated shared memory segment has been removed. It will disappear when the last process attached to the segment detaches it. 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 the last character is currently unused. Read permission is granted. Write permission is granted. Alter permission is granted. The indicated permission is not granted. The login name of the owner of the facility entry. The group name of the group of the owner of the facility entry. The login name of the creator of the facility entry. The group name of the group of the creator of the facility entry. The number of bytes in messages currently outstanding on the associated message queue. The number of messages currently outstanding on the associated message queue. The maximum number of bytes allowed in messages outstanding on the associated message queue. The process ID of the last process to send a message to the associated message queue. The process ID of the last process to receive a message from the associated message queue. The time the last message was sent to the associated message queue. The time the last message was received from the associated message queue. The time when the associated facility entry was created or changed. The number of processes attached to the associated shared memory segment. The size of the associated shared memory segment. The process ID of the creating process of the shared memory segment. The process ID of the last process to attach or detach the shared memory segment. The time the last attach was completed to the associated shared memory segment. The time the last detach was completed on the associated shared memory segment. The number of semaphores in the set associated with the semaphore entry. The time the last semaphore operation was completed on the set associated with the semaphore entry. WARNINGS
produces only an approximate indication of actual system status because system processes are continually changing while 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
Kernel virtual memory Group names User names System namelist SEE ALSO
msgop(2), semop(2), shmop(2). STANDARDS CONFORMANCE
ipcs(1)