# IPC(Inter Process Communication)는
message queue( q), shared mem ( m), semaphore (s)의 자원의 현황을 알려준다.
# ipcs - provide information on ipc facilities
# SYNOPSIS
ipcs [ -asmq ] [ -tclup ]
ipcs [ -smq ] -i id
ipcs -h
# IPC 모든 타입에 대한 리소스 정보 출력
# ====================================================================== #
# ipcs
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 3407872 nobody 600 328 11 dest
0x00000000 3440641 root 600 524288 11 dest
0x00000000 1998850 root 600 184324 11 dest
------ Semaphore Arrays --------
key semid owner perms nsems
0x00000000 1540096 nobody 600 1
------ Message Queues --------
key msqid owner perms used-bytes messages
# ====================================================================== #
# IPC 타입별 각각의 리소스 정보 출력
# ====================================================================== #
# ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 816906240 root 666 294912 20 dest
0x00000000 816939009 root 666 557056 20 dest
0x01024018 768442370 root 600 225304 0
0x00000000 771194883 root 666 294912 0
0x00000000 771227652 root 666 557056 0
0x0102400a 774569989 root 600 225304 0
0x01024017 816971782 root 600 225304 20
# ipcs -q
------ Message Queues --------
key msqid owner perms used-bytes messages
# ipcs -s
------ Semaphore Arrays --------
key semid owner perms nsems
0x00000000 12976128 root 666 1
0x00000000 13008897 root 666 1
0x00000000 17629186 root 666 1
0x00000000 17661955 root 666 1
0x00000000 30638084 root 666 1
0x00000000 30670853 root 666 1
0x00000000 13172742 root 666 1
0x00000000 13205511 root 666 1
0x00000000 30703624 nobody 600 1
0x00000000 30736393 nobody 600 1
0x00000000 30769162 nobody 600 1
0x00000000 30801931 nobody 600 1
# ====================================================================== #
예시)
ipcs -i www
ipcs -m
cat /proc/sys/kernel/shmmax
ipcs -l
ipcs -m -p
ipcs -m
ps 21162
ps 24312
ipcs -m
ipcrm -m 30605373
ipcs -m
ipcrm -m 30408759
ipcrm -m 31293508
ipcs -m > shmgts
less shmgts
vi rmshmgts m -p
ipcs -m
for i in $(cat rmshmgts); do ipcrm -m $i ;d