How to check if the script is already running? Post: 302990721

Sponsored Content

Top Forums UNIX for Beginners Questions & Answers How to check if the script is already running? Post 302990721 by RudiC on Tuesday 31st of January 2017 07:08:40 AM

01-31-2017

Registered User

Let me see if I understand the request correctly: You have a NAS mounted on a number of servers sharing a shell script on that NAS. Only one single server is allowed to run one instance of the script at a given point in time, all others should be locked out during that run. The result is server dependent and should be stored locally on the respective server.
As it is many servers, local lock mecanisms won't work. Unless the OS offers lock mechanisms across all servers, you have to create one on your own.
Reading through your posts, I'm not sure if you differentiate between the lock file and the result file. You need both of them. While you can store the results locally, you should create the lock file some place available to all servers. One example - not being everybody's preferred choice - would be the script's path on the NAS, or e.g. a "lock" directory thereunder. You could use a simple file name, or a "personalized" one as Corona688 proposed, and use Scrutinizer's trap to remove it at script exit - not forgetting for the "normal", healthy script end.
No running scripts should be killed by the mechanism, but the nth instance should quit graciously when it sees another instance running, possibly logging such event when quitting.

RudiC

View Public Profile for RudiC

Find all posts by RudiC

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

check that script is not running twice

using ps -ef | fgrep "ld_data" how do i write a script to check that it didn't already run Thanks

2. Shell Programming and Scripting

Check if trigger Script is running

HI, I have a script which will be running all the time...it is like a trigger.. wakesup every 10 minutes(trigger.sh) executes, and I want to write another script which monitors this script every one hour and if it finds that trigger script is not running it should start it and exit...and here...

3. Shell Programming and Scripting

Running a check platform script

Hi, I want to run a check platform & application script under ksh (Soaris boxes). It runs some commands and it take some time. I want to customize it like that: - output is too big, hence I want some output of the commands to be redirect ed in an output file (or maybe two or three) - not...

4. UNIX for Dummies Questions & Answers

check user id before running script

I am looking for the syntax to check which ID is executing script.sh. If the the ID, is not user1 then I want the script to exit and return to command prompt, if it is user1, then I want the script to continue. Any help would be greatly appreciate. Thank you. Chris

5. Shell Programming and Scripting

script to check if another script is running and if so, then sleep for sometime and check again

Hi, I am a unix newbie. I need to write a script to check wheteher another script is still running. If it is, then sleep for 30m and then check again if the script is running. If the script has stopped running then, I need to come out of the loop. I am using RHEL 5.2

6. UNIX for Dummies Questions & Answers

Help Running a Check in Bash Script

Hey guys, so I wrote a small script that pretty much just takes in two numbers and counts from the first to the second, e.g. unknown-hacker|544> count.sh 1 3 1 2 3 My problem is I want to make it so that if you input invalid parameters, such as non-numerical characters, more than 2...

7. Shell Programming and Scripting

Script to check running of process

Hi, Can anyone please tell me how to write a shell script to check whether a process if running or not.... if its still running then wait for sometime and if not then run the next query. Also, Under my one main script main.sh I have to run 2 scripts simutaneously which take some time to...

8. UNIX for Dummies Questions & Answers

[Solved] How to Check if a script is running?

Hi All, I am new to Unix... Can you please let me know how we can check if a script is running or not on Solaris box?

9. Linux

Check up the status of a Script (running or not)

Hello, i allready search on google und here in the local Forum, but can't found something. I need a query in php, that check whether a process (script) is running or not. Like this: php query: /usr/bin/Script01 >> if runnig, then: "Script01 is Online", if not "Script01 is Offline" I...

10. Shell Programming and Scripting

Check to see if script is already running

Happy New Year Is there a quick way to check to see if a script is already running. I want to put in a check in the script to exit, if already running. Currerntly i can only think of doing it the following way. # ps -ef | grep -i 3_HOUSEKEEPING_FFTVTL_TO_FFTDSSU_DUPLICATION.ksh |...

LEARN ABOUT REDHAT

shlock

SHLOCK(1)						      General Commands Manual							 SHLOCK(1)

NAME

       shlock - create lock files for use in shell scripts

SYNOPSIS

       shlock -p pid -f name [ -b ] [ -u ] [ -c ]

DESCRIPTION

       Shlock  tries  to  create  a  lock  file named name and write the process ID pid into it.  If the file already exists, shlock will read the
       process ID from the file and test to see if the process is currently running.  If the process exists, then the file will not be created.

       Shlock exits with a zero status if it was able to create the lock file, or non-zero if the file refers to currently-active process.

OPTIONS

       -b     Process IDs are normally read and written in ASCII.  If the ``-b'' flag is used, then they will be written as  a	binary	int.   For
	      compatibility with other systems, the ``-u'' flag is accepted as a synonym for ``-b'' since binary locks are used by many UUCP pack-
	      ages.

       -c     If the ``-c'' flag is used, then shlock will not create a lock file, but will instead use the file to see if the	lock  is  held	by
	      another  program.   If  the  lock  is  valid, the program will exit with a non-zero status; if the lock is not valid (i.e., invoking
	      shlock without the flag would have succeeded), then the program will exit with a zero status.

EXAMPLES

       The following example shows how shlock would be used within a shell script:
	      LOCK=<pathrun in inn.conf>/LOCK.send
	      trap 'rm -f ${LOCK} ; exit 1' 1 2 3 15
	      if shlock -p $$ -f ${LOCK} ; then
		  # Do appropriate work
	      else
		  echo Locked by `cat ${LOCK}`
	      fi

BUGS

       shlock does not assumed to be used under a number of lock/unlock environment in a short time.  Namely, shlock should be used for  an  envi-
       ronment like daily or hourly based job.

HISTORY

       Written by Rich $alz <rsalz@uunet.uu.net> after a description of HDB UUCP locking given by Peter Honeyman.  This is revision 1.5.6.1, dated
       2002/09/24.

SEE ALSO

       inn.conf(5)

																	 SHLOCK(1)

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

check that script is not running twice

Discussion started by: Link_02

2. Shell Programming and Scripting

Check if trigger Script is running

Discussion started by: mgirinath

3. Shell Programming and Scripting

Running a check platform script

Discussion started by: heartwork

4. UNIX for Dummies Questions & Answers

check user id before running script

Discussion started by: cpolikowsky