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ipcs - report System V interprocess communication facilities status

 

NAME

      ipcs - report System V interprocess communication facilities status
 

SYNOPSIS

      ipcs [-abcmopqstMQSTy] [-C core] [-N system] [-u user]
 

DESCRIPTION

      The ipcs utility provides information on System V interprocess communica‐
      tion (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 information about active shared memory segments.
 
      -o      Show outstanding usage for active message queues, and shared mem‐
              ory 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 information about active message queues.
 
      -s      Display information about active semaphores.
 
      -t      Show access times for active semaphores, message queues, and
              shared memory segments.  The access times is the time of the last
              control 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.
 
      -C core
              Extract values associated with the name list from the specified
              core instead of the default /dev/kmem.  Implies -y.
 
      -M      Display system information about shared memory.
 
      -N system
              Extract the name list from the specified system instead of the
              default /boot/kernel/kernel.  Implies -y.
 
      -Q      Display system information about messages queues.
 
      -S      Display system information about semaphores.
 
      -T      Display system information about shared memory, message queues
              and semaphores.
 
      -y      Use the kvm(3) interface instead of the sysctl(3) interface to
              extract the required information.  If ipcs is to operate on the
              running system, using kvm(3) will require read privileges to
              /dev/kmem.
 
      -u user
              Display information about IPC mechanisms owned by user.  User
              specification can be in the form of a numeric UID or a login
              name.
 
      If none of the -M, -m, -Q, -q, -S, or -s options are specified, informa‐
      tion 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.
 

FILES

      /dev/kmem            default kernel memory
      /boot/kernel/kernel  default system name list
      ipcrm(1)
 

AUTHORS

      Thorsten Lockert 〈tholo@sigmasoft.com〉
 

BUGS

      This manual page is woefully incomplete, because it does not at all
      attempt to explain the information printed by ipcs.
 

Sections

Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.