👤
Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:
Select Section of Man Page:
Select Man Page Repository:

Linux 2.6 - man page for ipcs (linux section 1posix)

IPCS(P) 			    POSIX Programmer's Manual				  IPCS(P)

NAME
       ipcs - report XSI interprocess communication facilities status

SYNOPSIS
       ipcs [-qms][-a | -bcopt]

DESCRIPTION
       The  ipcs  utility shall write information about active interprocess communication facili-
       ties.

       Without options, information shall be written in short format for message  queues,  shared
       memory  segments,  and  semaphore sets that are currently active in the system. Otherwise,
       the information that is displayed is controlled by the options specified.

OPTIONS
       The ipcs facility supports the Base Definitions volume  of  IEEE Std 1003.1-2001,  Section
       12.2, Utility Syntax Guidelines.

       The ipcs utility accepts the following options:

       -q     Write information about active message queues.

       -m     Write information about active shared memory segments.

       -s     Write information about active semaphore sets.

       If  -q, -m, or -s are specified, only information about those facilities shall be written.
       If none of these three are specified, information about all three shall be written subject
       to the following options:

       -a     Use all print options. (This is a shorthand notation for -b, -c, -o, -p, and -t.)

       -b     Write  information  on maximum allowable size. (Maximum number of bytes in messages
	      on queue for message queues, size of segments for shared memory, and number of sem-
	      aphores in each set for semaphores.)

       -c     Write creator's user name and group name; see below.

       -o     Write information on outstanding usage. (Number of messages on queue and total num-
	      ber of bytes in messages on queue for  message  queues,  and  number  of	processes
	      attached to shared memory segments.)

       -p     Write process number information. (Process ID of the last process to send a message
	      and process ID of the last process to receive a message on message queues,  process
	      ID  of the creating process, and process ID of the last process to attach or detach
	      on shared memory segments.)

       -t     Write time information. (Time of the last control operation that changed the access
	      permissions  for	all facilities, time of the last msgsnd() and msgrcv() operations
	      on message queues, time of the last shmat() and shmdt() operations on  shared  mem-
	      ory, and time of the last semop() operation on semaphores.)

OPERANDS
       None.

STDIN
       Not used.

INPUT FILES
	* The group database

	* The user database

ENVIRONMENT VARIABLES
       The following environment variables shall affect the execution of ipcs:

       LANG   Provide  a  default  value for the internationalization variables that are unset or
	      null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Inter-
	      nationalization Variables for the precedence of internationalization variables used
	      to determine the values of locale categories.)

       LC_ALL If set to a non-empty string value, override the values of all the  other  interna-
	      tionalization variables.

       LC_CTYPE
	      Determine  the  locale for the interpretation of sequences of bytes of text data as
	      characters (for example, single-byte as opposed to multi-byte characters	in  argu-
	      ments).

       LC_MESSAGES
	      Determine the locale that should be used to affect the format and contents of diag-
	      nostic messages written to standard error.

       NLSPATH
	      Determine the location of message catalogs for the processing of LC_MESSAGES .

       TZ     Determine the timezone for the date and time strings written by  ipcs.   If  TZ  is
	      unset or null, an unspecified default timezone shall be used.

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       An introductory line shall be written with the format:

	      "IPC status from %s as of %s\n", <source>, <date>

       where <source> indicates the source used to gather the statistics and <date> is the infor-
       mation that would be produced by the date command when invoked in the POSIX locale.

       The ipcs utility then shall create up to three reports depending upon the -q, -m,  and  -s
       options.   The first report shall indicate the status of message queues, the second report
       shall indicate the status of shared memory segments, and the third report  shall  indicate
       the status of semaphore sets.

       If the corresponding facility is not installed or has not been used since the last reboot,
       then the report shall be written out in the format:

	      "%s facility not in system.\n", <facility>

       where <facility> is Message Queue, Shared Memory, or Semaphore,	as  appropriate.  If  the
       facility has been installed and has been used since the last reboot, column headings sepa-
       rated by one or more spaces and followed by a <newline>	shall  be  written  as	indicated
       below followed by the facility name written out using the format:

	      "%s:\n", <facility>

       where  <facility>  is Message Queues, Shared Memory, or Semaphores, as appropriate. On the
       second and third reports the column headings need not be written if the last column  head-
       ings written already provide column headings for all information in that report.

       The  column headings provided in the first column below and the meaning of the information
       in those columns shall be given in order below; the letters in  parentheses  indicate  the
       options	that  shall cause the corresponding column to appear; "all" means that the column
       shall always appear. Each column is separated by one or more  <space>s.	Note  that  these
       options only determine what information is provided for each report; they do not determine
       which reports are written.

       T (all)
	      Type of facility:

       q
	      Message queue.

       m
	      Shared memory segment.

       s
	      Semaphore.

       This field is a single character written using the format %c .

       ID (all)
	      The identifier for the facility entry. This field shall be written using the format
	      %d .

       KEY (all)
	      The key used as an argument to msgget(), semget(), or shmget() to create the facil-
	      ity 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.

       This field shall be written using the format 0x%x.

       MODE (all)
	      The  facility  access modes and flags. The mode shall consist of 11 characters that
	      are interpreted as follows.

       The first character shall be:

       S
	      If a process is waiting on a msgsnd() operation.

       -
	      If the above is not true.

       The second character shall be:

       R
	      If a process is waiting on a msgrcv() operation.

       C or -
	      If the associated shared memory segment is to be	cleared  when  the  first  attach
	      operation is executed.

       -
	      If none of the above is true.

       The  next nine characters shall be 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	usergroup
       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 a minus sign ( '-' ).

       The permissions shall be indicated as follows:

       r
	      If read permission is granted.

       w
	      If write permission is granted.

       a
	      If alter permission is granted.

       -
	      If the indicated permission is not granted.

       The  first character following the permissions specifies if there is an alternate or addi-
       tional access control method associated with the facility. If there  is	no  alternate  or
       additional  access  control method associated with the facility, a single <space> shall be
       written; otherwise, another printable character is written.

       OWNER (all)
	      The user name of the owner of the facility entry. If the user name of the owner  is
	      found  in  the user database, at least the first eight column positions of the name
	      shall be written using the format %s . Otherwise, the user ID of the owner shall be
	      written using the format %d .

       GROUP (all)
	      The  group  name of the owner of the facility entry. If the group name of the owner
	      is found in the group database, at least the first eight column  positions  of  the
	      name  shall  be  written using the format %s . Otherwise, the group ID of the owner
	      shall be written using the format %d .

       The following nine columns shall be only written out for message queues:

       CREATOR (a,c)
	      The user name of the creator of the facility entry. If the user name of the creator
	      is  found  in  the  user database, at least the first eight column positions of the
	      name shall be written using the format %s . Otherwise, the user ID of  the  creator
	      shall be written using the format %d .

       CGROUP (a,c)
	      The  group name of the creator of the facility entry. If the group name of the cre-
	      ator is found in the group database, at least the first eight column  positions  of
	      the name shall be written using the format %s . Otherwise, the group ID of the cre-
	      ator shall be written using the format %d .

       CBYTES (a,o)
	      The number of bytes in messages currently outstanding  on  the  associated  message
	      queue. This field shall be written using the format %d .

       QNUM (a,o)
	      The  number of messages currently outstanding on the associated message queue. This
	      field shall be written using the format %d .

       QBYTES (a,b)
	      The maximum number of bytes allowed in messages outstanding on the associated  mes-
	      sage queue. This field shall be written using the format %d .

       LSPID (a,p)
	      The  process ID of the last process to send a message to the associated queue. This
	      field shall be written using the format:

	      "%d", <pid>

       where <pid> is 0 if no message has been sent to the corresponding  message  queue;  other-
       wise, <pid> shall be the process ID of the last process to send a message to the queue.

       LRPID (a,p)
	      The  process ID of the last process to receive a message from the associated queue.
	      This field shall be written using the format:

	      "%d", <pid>

       where <pid> is 0 if no message has been received from  the  corresponding  message  queue;
       otherwise, <pid> shall be the process ID of the last process to receive a message from the
       queue.

       STIME (a,t)
	      The time the last message was sent to the associated queue. If a message	has  been
	      sent  to	the corresponding message queue, the hour, minute, and second of the last
	      time a message was sent to the queue shall be written using the format %d : %2.2d :
	      %2.2d . Otherwise, the format " no-entry" shall be written.

       RTIME (a,t)
	      The time the last message was received from the associated queue.  If a message has
	      been received from the corresponding message queue, the hour, minute, and second of
	      the last time a message was received from the queue shall be written using the for-
	      mat %d : %2.2d : %2.2d . Otherwise, the format " no-entry" shall be written.

       The following eight columns shall be only written out for shared memory segments.

       CREATOR (a,c)
	      The user of the creator of the facility entry. If the user name of the  creator  is
	      found  in  the user database, at least the first eight column positions of the name
	      shall be written using the format %s . Otherwise, the user ID of the creator  shall
	      be written using the format %d .

       CGROUP (a,c)
	      The  group name of the creator of the facility entry. If the group name of the cre-
	      ator is found in the group database, at least the first eight column  positions  of
	      the name shall be written using the format %s . Otherwise, the group ID of the cre-
	      ator shall be written using the format %d .

       NATTCH (a,o)
	      The number of processes attached to the associated  shared  memory  segment.   This
	      field shall be written using the format %d .

       SEGSZ (a,b)
	      The size of the associated shared memory segment. This field shall be written using
	      the format %d .

       CPID (a,p)
	      The process ID of the creator of the shared memory entry. This field shall be writ-
	      ten using the format %d .

       LPID (a,p)
	      The  process  ID of the last process to attach or detach the shared memory segment.
	      This field shall be written using the format:

	      "%d", <pid>

       where <pid> is 0 if no process has attached the corresponding shared memory segment;  oth-
       erwise, <pid> shall be the process ID of the last process to attach or detach the segment.

       ATIME (a,t)
	      The  time the last attach on the associated shared memory segment was completed. If
	      the corresponding shared memory segment has ever been attached, the  hour,  minute,
	      and  second  of  the  last time the segment was attached shall be written using the
	      format %d : %2.2d : %2.2d . Otherwise, the format " no-entry" shall be written.

       DTIME (a,t)
	      The time the last detach on the associated shared memory segment was completed.  If
	      the  corresponding  shared memory segment has ever been detached, the hour, minute,
	      and second of the last time the segment was detached shall  be  written  using  the
	      format %d : %2.2d : %2.2d . Otherwise, the format " no-entry" shall be written.

       The following four columns shall be only written out for semaphore sets:

       CREATOR (a,c)
	      The  user  of the creator of the facility entry. If the user name of the creator is
	      found in the user database, at least the first eight column positions of	the  name
	      shall  be written using the format %s . Otherwise, the user ID of the creator shall
	      be written using the format %d .

       CGROUP (a,c)
	      The group name of the creator of the facility entry. If the group name of the  cre-
	      ator  is	found in the group database, at least the first eight column positions of
	      the name shall be written using the format %s . Otherwise, the group ID of the cre-
	      ator shall be written using the format %d .

       NSEMS (a,b)
	      The number of semaphores in the set associated with the semaphore entry. This field
	      shall be written using the format %d .

       OTIME (a,t)
	      The time the last semaphore operation on the  set  associated  with  the	semaphore
	      entry was completed. If a semaphore operation has ever been performed on the corre-
	      sponding semaphore set, the hour, minute, and second of the last	semaphore  opera-
	      tion  on	the  semaphore set shall be written using the format %d : %2.2d : %2.2d .
	      Otherwise, the format " no-entry" shall be written.

       The following column shall be written for all three reports when it is requested:

       CTIME (a,t)
	      The time the associated entry was created or changed. The hour, minute, and  second
	      of the time when the associated entry was created shall be written using the format
	      %d : %2.2d : %2.2d .

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

	0     Successful completion.

       >0     An error occurred.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       Things can change while ipcs is running; the information it  gives  is  guaranteed  to  be
       accurate only when it was retrieved.

EXAMPLES
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       The  System  Interfaces	volume	of  IEEE Std 1003.1-2001,  msgrcv(),  msgsnd(), semget(),
       semop(), shmat(), shmdt(), shmget()

COPYRIGHT
       Portions of this text are reprinted and	reproduced  in	electronic  form  from	IEEE  Std
       1003.1,	2003  Edition,	Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard, the original IEEE and The Open Group Standard is the referee document. The orig-
       inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group			       2003					  IPCS(P)


All times are GMT -4. The time now is 02:26 AM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
×
UNIX.COM Login
Username:
Password:  
Show Password