ipc inter process communication (shared memory) linux commnad

[root@vikas ~]# whatis ipcs
ipcs (1p) - report XSI interprocess communication facilities status
ipcs (1) - provide information on ipc facilities
he ipcs command is a powerful mechanism for spying on the kernel memory of IPC objects.

ipcs -s
ipcs -m
ipcs -q
ipcs -i id

Unix Shared Memory Variables

SHMMAX	The maximum amount of shared memory, normally 131072 bytes
SHMMIN	The minimum amount of shared memory, normally 1 byte
SHMMNI	The maximum number of shared memory segments in the system, normally 100
SHMSEG	The maximum number of shared memory segments per process, normally 6

IPCRM

ipcrm deletes IPC objects from the kernel. However, as IPC objects can be deleted through system calls in the user's program, there is often no need to delete them by hand. The command is very simple:

ipcrm -type id

[root@vikas ~]# whatis ipcrm
ipcrm (1p) - remove an XSI message queue, semaphore set, or shared memory segment identifier
ipcrm (1) - remove a message queue, semaphore set or shared memory id

usage: ipcrm [ [-q msqid] [-m shmid] [-s semid]
[-Q msgkey] [-M shmkey] [-S semkey] ... ]

IPCClean

ipcclean
ipcclean (1) - remove shared memory and semaphores from a failed PostgreSQL server