This question already has answers here:
Linux Script to check if process is running and act on the result
(8 answers)
Closed 5 years ago.
I wrote a bash-script to check if a process is running. It doesn't work since the ps command always returns exit code 1. When I run the ps command from the command-line, the $? is correctly set, but within the script it is always 1. Any idea?
#!/bin/bash
SERVICE=$1
ps -a | grep -v grep | grep $1 > /dev/null
result=$?
echo "exit code: ${result}"
if [ "${result}" -eq "0" ] ; then
echo "`date`: $SERVICE service running, everything is fine"
else
echo "`date`: $SERVICE is not running"
fi
Bash version: GNU bash, version 3.2.25(1)-release (x86_64-redhat-linux-gnu)
There are a few really simple methods:
pgrep procname && echo Running
pgrep procname || echo Not running
killall -q -0 procname && echo Running
pidof procname && echo Running
This trick works for me. Hope this could help you. Let's save the followings as checkRunningProcess.sh
#!/bin/bash
ps_out=`ps -ef | grep $1 | grep -v 'grep' | grep -v $0`
result=$(echo $ps_out | grep "$1")
if [[ "$result" != "" ]];then
echo "Running"
else
echo "Not Running"
fi
Make the checkRunningProcess.sh executable.And then use it.
Example to use.
20:10 $ checkRunningProcess.sh proxy.py
Running
20:12 $ checkRunningProcess.sh abcdef
Not Running
I tried your version on BASH version 3.2.29, worked fine. However, you could do something like the above suggested, an example here:
#!/bin/sh
SERVICE="$1"
RESULT=`ps -ef | grep $1 | grep -v 'grep' | grep -v $0`
result=$(echo $ps_out | grep "$1")
if [[ "$result" != "" ]];then
echo "Running"
else
echo "Not Running"
fi
I use this one to check every 10 seconds process is running and start if not and allows multiple arguments:
#!/bin/sh
PROCESS="$1"
PROCANDARGS=$*
while :
do
RESULT=`pgrep ${PROCESS}`
if [ "${RESULT:-null}" = null ]; then
echo "${PROCESS} not running, starting "$PROCANDARGS
$PROCANDARGS &
else
echo "running"
fi
sleep 10
done
Check if your scripts name doesn't contain $SERVICE. If it does, it will be shown in ps results, causing script to always think that service is running. You can grep it against current filename like this:
#!/bin/sh
SERVICE=$1
if ps ax | grep -v grep | grep -v $0 | grep $SERVICE > /dev/null
then
echo "$SERVICE service running, everything is fine"
else
echo "$SERVICE is not running"
fi
Working one.
!/bin/bash
CHECK=$0
SERVICE=$1
DATE=`date`
OUTPUT=$(ps aux | grep -v grep | grep -v $CHECK |grep $1)
echo $OUTPUT
if [ "${#OUTPUT}" -gt 0 ] ;
then echo "$DATE: $SERVICE service running, everything is fine"
else echo "$DATE: $SERVICE is not running"
fi
Despite some success with the /dev/null approach in bash. When I pushed the solution to cron it failed. Checking the size of a returned command worked perfectly though. The ampersrand allows bash to exit.
#!/bin/bash
SERVICE=/path/to/my/service
result=$(ps ax|grep -v grep|grep $SERVICE)
echo ${#result}
if ${#result}> 0
then
echo " Working!"
else
echo "Not Working.....Restarting"
/usr/bin/xvfb-run -a /opt/python27/bin/python2.7 SERVICE &
fi
#!/bin/bash
ps axho comm| grep $1 > /dev/null
result=$?
echo "exit code: ${result}"
if [ "${result}" -eq "0" ] ; then
echo "`date`: $SERVICE service running, everything is fine"
else
echo "`date`: $SERVICE is not running"
/etc/init.d/$1 restart
fi
Something like this
Those are helpful hints. I just needed to know if a service was running when I started the script, so I could leave the service in the same state when I left. I ended up using this:
HTTPDSERVICE=$(ps -A | grep httpd | head -1)
[ -z "$HTTPDSERVICE" ] && echo "No apache service running."
I found the problem. ps -ae instead ps -a works.
I guess it has to do with my rights in the shared hosting environment. There's apparently a difference between executing "ps -a" from the command line and executing it from within a bash-script.
A simple script version of one of Andor's above suggestions:
!/bin/bash
pgrep $1 && echo Running
If the above script is called test.sh then, in order to test, type:
test.sh NameOfProcessToCheck
e.g.
test.sh php
I was wondering if it would be a good idea to have progressive attempts at a process, so you pass this func a process name func_terminate_process "firefox" and it tires things more nicely first, then moves on to kill.
# -- NICE: try to use killall to stop process(s)
killall ${1} > /dev/null 2>&1 ;sleep 10
# -- if we do not see the process, just end the function
pgrep ${1} > /dev/null 2>&1 || return
# -- UGLY: Step trough every pid and use kill -9 on them individually
for PID in $(pidof ${1}) ;do
echo "Terminating Process: [${1}], PID [${PID}]"
kill -9 ${PID} ;sleep 10
# -- NASTY: If kill -9 fails, try SIGTERM on PID
if ps -p ${PID} > /dev/null ;then
echo "${PID} is still running, forcefully terminating with SIGTERM"
kill -SIGTERM ${PID} ;sleep 10
fi
done
# -- If after all that, we still see the process, report that to the screen.
pgrep ${1} > /dev/null 2>&1 && echo "Error, unable to terminate all or any of [${1}]" || echo "Terminate process [${1}] : SUCCESSFUL"
I need to do this from time to time and end up hacking the command line until it works.
For example, here I want to see if I have any SSH connections, (the 8th column returned by "ps" is the running "path-to-procname" and is filtered by "awk":
ps | awk -e '{ print $8 }' | grep ssh | sed -e 's/.*\///g'
Then I put it in a shell-script, ("eval"-ing the command line inside of backticks), like this:
#!/bin/bash
VNC_STRING=`ps | awk -e '{ print $8 }' | grep vnc | sed -e 's/.*\///g'`
if [ ! -z "$VNC_STRING" ]; then
echo "The VNC STRING is not empty, therefore your process is running."
fi
The "sed" part trims the path to the exact token and might not be necessary for your needs.
Here's my example I used to get your answer. I wrote it to automatically create 2 SSH tunnels and launch a VNC client for each.
I run it from my Cygwin shell to do admin to my backend from my windows workstation, so I can jump to UNIX/LINUX-land with one command, (this also assumes the client rsa keys have already been "ssh-copy-id"-ed and are known to the remote host).
It's idempotent in that each proc/command only fires when their $VAR eval's to an empty string.
It appends " | wc -l" to store the number of running procs that match, (i.e., number of lines found), instead of proc-name for each $VAR to suit my needs. I keep the "echo" statements so I can re-run and diagnose the state of both connections.
#!/bin/bash
SSH_COUNT=`eval ps | awk -e '{ print $8 }' | grep ssh | sed -e 's/.*\///g' | wc -l`
VNC_COUNT=`eval ps | awk -e '{ print $8 }' | grep vnc | sed -e 's/.*\///g' | wc -l`
if [ $SSH_COUNT = "2" ]; then
echo "There are already 2 SSH tunnels."
elif [ $SSH_COUNT = "1" ]; then
echo "There is only 1 SSH tunnel."
elif [ $SSH_COUNT = "0" ]; then
echo "connecting 2 SSH tunnels."
ssh -L 5901:localhost:5901 -f -l USER1 HOST1 sleep 10;
ssh -L 5904:localhost:5904 -f -l USER2 HOST2 sleep 10;
fi
if [ $VNC_COUNT = "2" ]; then
echo "There are already 2 VNC sessions."
elif [ $VNC_COUNT = "1" ]; then
echo "There is only 1 VNC session."
elif [ $VNC_COUNT = "0" ]; then
echo "launching 2 vnc sessions."
vncviewer.exe localhost:1 &
vncviewer.exe localhost:4 &
fi
This is very perl-like to me and possibly more unix utils than true shell scripting. I know there are lots of "MAGIC" numbers and cheezy hard-coded values but it works, (I think I'm also in poor taste for using so much UPPERCASE too). Flexibility can be added with some cmd-line args to make this more versatile but I wanted to share what worked for me. Please improve and share. Cheers.
A solution with service and awk that takes in a comma-delimited list of service names.
First it's probably a good bet you'll need root privileges to do what you want. If you don't need to check then you can remove that part.
#!/usr/bin/env bash
# First parameter is a comma-delimited string of service names i.e. service1,service2,service3
SERVICES=$1
ALL_SERVICES_STARTED=true
if [ $EUID -ne 0 ]; then
if [ "$(id -u)" != "0" ]; then
echo "root privileges are required" 1>&2
exit 1
fi
exit 1
fi
for service in ${SERVICES//,/ }
do
STATUS=$(service ${service} status | awk '{print $2}')
if [ "${STATUS}" != "started" ]; then
echo "${service} not started"
ALL_SERVICES_STARTED=false
fi
done
if ${ALL_SERVICES_STARTED} ; then
echo "All services started"
exit 0
else
echo "Check Failed"
exit 1
fi
The most simple check by process name :
bash -c 'checkproc ssh.exe ; while [ $? -eq 0 ] ; do echo "proc running";sleep 10; checkproc ssh.exe; done'
I did a script to execute every 10 minutes and when the files open on my Java app is greater than 10000 it will execute a jmap command to give to me a heapdump.
My intention is to discover which class of my app is not closing the files or where there is a memory leak or why I receive the message "Too many files open" after 20 hours executing it.
This is my script. Does anybody have other ways or tools to discover where my app is not closing the files? Thanks a lot!
#!/bin/bash
rm openfiles.log
flag=1
for (( ; ; ))
do
sleep 10m
files=`ps -A x |grep iscsi | awk '{print $1}' | xargs -I '{}' ls /proc/29192/fd | wc -l`
msg="open files: $files - date: `date`"
echo "$msg - infinite loops [ hit CTRL+C to stop]"
echo $msg >> openfiles.log
if [ $files -gt 10000 ] && [ $flag -eq 1 ]
then
jmap -F -dump:file=heapdump.hprof 29192
flag=0;
echo "############################################ heapdump of 29192" >> openfiles.log
fi
echo "" >> openfiles.log
done
Take a look at File Leak Detector written by Kohsuke Kawaguchi of Jenkins fame. It is a java agent that you attach to your java process.
There are also other ways to scan for them via FindBugs/PMD, etc. I'd take a look at SonarQube. There are rules specifically about not closing resources.
I am new to Linux. I don't know about shell scripts. I need to get the idle process time of a given Linux process. I am writing a Java program. But there are no Linux commands for my need. How do I write a shell script that could do this? Then I can execute this script from Java.
Here you are:
#! /bin/bash
# Assumptions:
# Process is attached to a tty.
#
[[ -z "$1" ]] && echo "Usage: $0 pid" && exit 1
[[ "$1" != +([0-9]) ]] && echo "$1 is not a valid pid" && exit 1
PID="$1"
W=$(which w)
PS=$(which ps)
SED=$(which sed)
AWK=$(which awk)
TTY=$($PS -o tty4 $PID)
TTNo=$(echo "$TTY" | $SED -e '/TTY/d')
TIME=$($W | $SED -n -e "/pts\/$TTNo/p" | $AWK '{ print $5 }')
echo $PID has been idle for $TIME
I am running a job in Jenkins(Jenkins is an open source continuous integration tool) by executing a list of shell commands. One of the command is to run a Java program which does some data validation. If meets with invalid date, the Java program will exit with a none-zero exit code so that Jenkins can discover that this time the build fails.
Unfortunately the Java program prints too much log to stdout and stderr, only a few of them are useful. Since the Java program can not be modified, I decide to filter the output with grep. So I wrote the shell as:
java -cp $CLASSPATH MetaValidatorMain | grep -v "useless keyword1"| grep -v "useless keyword2"
But the problem is that, after the execution of the line of shell, the parent process(Jenkins) got exit code of grep indead of java, so that Jenkins could not determine whether the build was success.
I also tried this:
(java -cp $CLASSPATH MetaValidatorMain || exit 1) | grep -v "useless keyword1"| grep -v "useless keyword2"
also did not work.
Could anyone tell me how could I write the line of shell to filter output and obtain the right exit code at the same.
thx
Bit of a long way round, but you could redirect the program output to a file, capture the return and then grep the output file for the content you want:
java -cp $CLASSPATH MetaValidatorMain > /tmp/outfile.txt 2>&1
RETURN_CODE=$?
grep -v "useless keyword1" /tmp/outfile | grep -v "useless keyword2"
exit RETURN_CODE
There are 3 ways of doing this. However your current setup should work. The reason here being that the grep won't match anything if the command fails, so grep will return with status 1 (unless the program always shows that text no matter what).
Pipefail
The first way is to set the pipefail option. This is the simplest and what it does is basically set the exit status $? to the exit code of the last program to exit non-zero (or zero if all exited successfully).
# false | true; echo $?
0
# set -o pipefail
# false | true; echo $?
1
$PIPESTATUS
Bash also has a variable called $PIPESTATUS which contains the exit status of all the programs in the last command.
# true | true; echo "${PIPESTATUS[#]}"
0 0
# false | true; echo "${PIPESTATUS[#]}"
1 0
# false | true; echo "${PIPESTATUS[0]}"
1
# true | false; echo "${PIPESTATUS[#]}"
0 1
You can use the 3rd command example to get the specific value in the pipeline that you need.
This solution might not be available though. I think $PIPESTATUS might have been added in a fairly recent version of bash, and your OS may not have it.
Separate executions
This is the most unwieldy of the solutions. Run each command separately and capture the status
# java -cp $CLASSPATH MetaValidatorMain > /tmp/outfile.txt 2>&1
# RETURN_CODE=$?
# grep -v "useless keyword1" /tmp/outfile | grep -v "useless keyword2"
# exit RETURN_CODE
I have a java jar program that I am trying to run on startup of my machine. Ideally, the shells script will check every 60 seconds to assure that the jar is running. How do I check if the jar is running on centos, this does not appear to be working?
My current .sh file:
#!/bin/bash
while [ true ]
do
cnt=`ps -eaflc --sort stime | grep /home/Portal.jar |grep -v grep | wc -l`
if(test $cnt -eq 3);
then
echo "Service already running..."
else
echo "Starting Service"
java -jar /home/Portal.jar >> /dev/null &
fi
sleep 1m
done
I used this for referencing so far.
Depending on what your program does, there may be more or less intelligent ways to check it. For example, if you have some server, it will listen on a port.
Then something like
netstat -an | fgrep tcp | fgrep LISTEN | fgrep :87654 # or whatever your port is
could do the job.
Then there is lsof, which could also detect listening ports.
Finally, you could connect and issue a pseudo request. For example, for a http server, you could use lynx or curl. For a server with a non-stamdard protocol, you can write a small client program whose sole purpose is to connect to the server just to see if it is there.
Store your process id in file and check for this process.
#!/bin/bash
while [ true ]
do
pid=$(cat /tmp/portal.pid)
if [[ -n "$pid" && $(ps -p $pid | wc -l) -eq 2 ]]
then
echo "Service already running..."
else
echo "Starting Service"
java -jar /home/Portal.jar >> /dev/null &
echo $! > /tmp/portal.pid
fi
sleep 1m
done
/tmp will be cleared on restart, all right in this case.
I did the very same scenario a couple of months ago. My task was to ensure a jar distributed java program to run 24/7 on a Linux server.
My program was console-based, started, did something then stopped.
I did a shell script that started, waited to end and then re-started the app in an infinite loop.
I installed runit, created a service and supplied this script as the run script. Works very well.
In general, the shell script ensures that the java program is running and runit ensures that the start script (which is our script) is running.
You find valuable info here: http://smarden.org/runit/faq.html
Rather than putting the process to sleep , I'd rather have it exit and use crontab to run the process every 1 min;which will check if its running or else just stop the script.
#!/bin/sh
declare -a devId=( "/Path/To/TestJar.jar Test1" "/Path/To/TestJar.jar Test2" ) #jarfile with pathname and Test as argument
# get length of an array
arraylength=${#devId[#]}
# use for loop to read all values and indexes
for (( i=1; i<${arraylength}+1; i++ ));
do
y=${devId[$i-1]}
cnt=`ps -eaflc --sort stime | grep "$y" |grep -v grep | wc -l`
if [ $cnt = 0 ]
then
java -jar $y& > /dev/null
b=$(basename $y)
echo $b
#DO SOME OPERATION LIKE SEND AN EMAIL OR ADD TO LOG FILE
continue
elif [ $cnt != 0 ]
then
echo 'do nothing'
fi
done
Why do you think $cnt should be equal to 3? Shouldn't it be equal to 1 if the process is already running?
You could use the jps command. It return the JVMs running in the system.
I created following script to monitor my application jar is running or not.
In this case My application jar is running on port 8080
#!/bin/bash
check=$(netstat -an | grep 8080 | wc -l)
if [[ $check -eq 0 ]];then
echo "jar is not running..."
/usr/bin/java -jar /path/to/target/application.jar >> /dev/null &
else
echo "it is running"
fi
I am using cronjob to monitor jar app by executing shell script on every minute.
$ crontab -e
in the end of file
* * * * * /bin/bash monitor-jar.sh /dev/null 2>&1