Bash script to check running process

Question

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  gt   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

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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  amp      else             echo  running      fi     sleep 10 done

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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

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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   gt   dev null 2 gt  amp 1  sleep 10    -- if we do not see the process  just end the function pgrep   1   gt   dev null 2 gt  amp 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   gt   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   gt   dev null 2 gt  amp 1  amp  amp  echo  Error  unable to terminate all or any of    1       echo  Terminate process    1     SUCCESSFUL

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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

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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  amp      vncviewer exe localhost 4  amp  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

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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

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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 gt  amp 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

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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     amp  amp   echo  No apache service running

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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

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A simple script version of one of Andor s above suggestions     bin bash  pgrep  1  amp  amp  echo Running   If the above script is called test sh then  in order to test  type  test sh NameOfProcessToCheck  e g  test sh php

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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

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There are a few really simple methods   pgrep procname  amp  amp  echo Running  pgrep procname    echo Not running  killall -q -0 procname  amp  amp  echo Running  pidof procname  amp  amp  echo Running

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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

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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  gt   dev null then     echo   SERVICE service running  everything is fine  else     echo   SERVICE is not running  fi

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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  gt  0  then         echo   Working   else         echo  Not Working     Restarting           usr bin xvfb-run -a  opt python27 bin python2 7 SERVICE  amp  fi

[bash] Bash script to check running process

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