Delete all SYSTEM V shared memory and semaphores o

问题:

How can I delete all not used semaphores and shared memory with a single command on a UNIX-like system, e.g., Ubuntu?

回答1:

Here, save and try this script (kill_ipcs.sh) on your shell:

#!/bin/bash

ME=`whoami`

IPCS_S=`ipcs -s | egrep "0x[0-9a-f]+ [0-9]+" | grep $ME | cut -f2 -d" "`
IPCS_M=`ipcs -m | egrep "0x[0-9a-f]+ [0-9]+" | grep $ME | cut -f2 -d" "`
IPCS_Q=`ipcs -q | egrep "0x[0-9a-f]+ [0-9]+" | grep $ME | cut -f2 -d" "`


for id in $IPCS_M; do
  ipcrm -m $id;
done

for id in $IPCS_S; do
  ipcrm -s $id;
done

for id in $IPCS_Q; do
  ipcrm -q $id;
done

We use it whenever we run IPCS programs in the university student server. Some people don't always cleanup so...it's needed :P

回答2:

ipcs -s | grep $USERNAME | perl -e 'while (<STDIN>) { @a=split(/\s+/); print `ipcrm sem $a[1]`}'

or

ipcs -s | grep $USERNAME | awk ' { print $2 } ' | xargs ipcrm sem

Change $USERNAME to a real username.

回答3:

This works on my Mac OS:

for n in `ipcs -b -m | egrep ^m | awk '{ print $2; }'`; do ipcrm -m $n; done

回答4:

I don't know how to delete all at once, but you can use ipcs to list resources, and then use loop and delete with ipcrm. This should work, but it needs a little work. I remember that I made it work once in class.

回答5:

#!/bin/bash
ipcs -m | grep `whoami` | awk '{ print $2 }' | xargs -n1 ipcrm -m
ipcs -s | grep `whoami` | awk '{ print $2 }' | xargs -n1 ipcrm -s
ipcs -q | grep `whoami` | awk '{ print $2 }' | xargs -n1 ipcrm -q

回答6:

This is how I do it in FreeBSD:

#!/usr/local/bin/bash
for i in $(ipcs -a | grep "^s" | awk '{ print $2 }');
do
        echo "ipcrm -s $i"
        ipcrm -s $i
done

回答7:

Check if there is anything to delete with :

ipcs -a | grep `whoami`

On linux delete them all via :

ipcs | nawk -v u=`whoami` '/Shared/,/^$/{ if($6==0&&$3==u) print "ipcrm shm",$2,";"}/Semaphore/,/^$/{ if($3==u) print "ipcrm sem",$2,";"}' | /bin/sh

For sun it would be :

ipcs -a | nawk -v u=`whoami` '$5==u &&(($1=="m" && $9==0)||($1=="s")){print "ipcrm -"$1,$2,";"}' | /bin/sh

courtsesy of di.uoa.gr

Check again if all is ok

For deleting your sems/shared mem - supposing you are a user in a workstation with no admin rights

回答8:

1 line will do all

For message queue

ipcs -q | sed "$ d; 1,2d" |  awk '{ print "Removing " $2; system("ipcrm -q " $2) }'

ipcs -q will give the records of message queues

sed "$ d; 1,2d " will remove last blank line ("$ d") and first two header lines ("1,2d")

awk will do the rest i.e. printing and removing using command "ipcrm -q" w.r.t. the value of column 2 (coz $2)

回答9:

Since you mentioned that you're working on a NFS system, do you have access to those semaphores and shared memory? I think you misunderstood what they are, they are an API code that enables processes to communicate with each other, semaphores are a solution for preventing race conditions and for threads to communicate with each other, in simple answer, they do not leave any residue on any filesystem.

Unless you are using an socket or a pipe? Do you have the necessary permissions to remove them, why are they on an NFS system?

Hope this helps, Best regards, Tom.

回答10:

In addition to bvamos's answer, according to the documentation the use of sem is deprecated :

NAME ipcrm - remove a message queue, semaphore set or shared memory id SYNOPSIS ipcrm [ -M key | -m id | -Q key | -q id | -S key | -s id ] ... deprecated usage

ipcrm [ shm | msg | sem ] id ...

remove shared memory

us ipcrm -m to remove a shared memory segment by the id

#!/bin/bash

set IPCS_M = ipcs -m | egrep "0x[0-9a-f]+ [0-9]+" | grep $USERNAME | cut -f2 -d" "

for id in $IPCS_M; do
  ipcrm -m $id;
done

or ipcrm -M to remove a shared memory segment by the key

#!/bin/bash

set IPCS_M = ipcs -m | egrep "0x[0-9a-f]+ [0-9]+" | grep $USERNAME | cut -f1 -d" "

for id in $IPCS_M; do
  ipcrm -M $id;
done

remove message queues

us ipcrm -q to remove a shared memory segment by the id

#!/bin/bash

set IPCS_Q = ipcs -q | egrep "0x[0-9a-f]+ [0-9]+" | grep $USERNAME | cut -f2 -d" "

for id in $IPCS_Q; do
  ipcrm -q $id;
done

or ipcrm -Q to remove a shared memory segment by the key

#!/bin/bash

set IPCS_Q = ipcs -q | egrep "0x[0-9a-f]+ [0-9]+" | grep $USERNAME | cut -f1 -d" "

for id in $IPCS_Q; do
  ipcrm -Q $id;
done

remove semaphores

us ipcrm -s to remove a semaphore segment by the id

#!/bin/bash

set IPCS_S = ipcs -s | egrep "0x[0-9a-f]+ [0-9]+" | grep $USERNAME | cut -f2 -d" "

for id in $IPCS_S; do
  ipcrm -s $id;
done

or ipcrm -S to remove a semaphore segment by the key

#!/bin/bash

set IPCS_S = ipcs -s | egrep "0x[0-9a-f]+ [0-9]+" | grep $USERNAME | cut -f1 -d" "

for id in $IPCS_S; do
  ipcrm -S $id;
done

回答11:

to remove all shared memory segments on FreeBSD

#!/bin/sh
for i in $(ipcs -m | awk '{ print $2 }' | sed 1,2d);
do
    echo "ipcrm -m $i"
    ipcrm -m $i
done

to remove all semaphores

#!/bin/sh
for i in $(ipcs -s | awk '{ print $2 }' | sed 1,2d);
do
    echo "ipcrm -s $i"
    ipcrm -s $i
done