Write me a simple Linux shell script! Payment of $5

[L.C.]

I will pay $5 USD via PayPal or money order to write a very simple Linux shell script and meets the described criteria.

 

The script will be executed through Cron scheduling every minute; the script itself should check to see if said process is running, and if not -- execute it. Simple as that.

 

You will receive payment upon successful completion, which includes testing and examination for quality assurance (integrity, security, and free of bugs and problems).

 

The script will be used to assist BlueT in Linux hosting (provided by L Y N X) in the Subspace realm.

[MikeTheNose]

Are you sure you're not overpaying for a script that is incredibly popular?

[»D1st0rt]

The ideal method to check and restart would depend on the process, some things use pid files and/or have specific scripts or command line arguments to kick them off in the way you want

[Gannon8]

Doesn't ASSS write it's PID to a file? See, thats how long I have been away from continuum. =P

[Samapico]

I did some bash script at school that parsed the ps output to build a tree of processes, with the parentid's and stuff...

 

It sucked... bash is the worst coding language ever conceived. Part of my linux-hate comes from that class

[»Lynx]

I'll write one later for free once I'm done with this damn database assignment.

[»Lynx]

Okay, here's a script:

 

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processName = "appName" # the process to check

processLocation = "path/to/location" # the path to the application to open
application = "nameOfApplication" # the name of the application to open

for line in os.popen("ps -A | grep " +processName):
fields = line.split()
pid = fields[0]
if os.path.exists("/proc/" +pid) == False:
	os.popen(processLocation + application)
elif os.path.exists("/proc/" +pid) == True:
	exit()

 

Test it, and let me know of any errors. You'll need to chmod the script to run it with crontab.

 

Just a note: run this script with the same permission level as the application you're going to be running, otherwise expect /proc issues.

Edited January 2, 2010 by Lynx

[L.C.]

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processName = "dirserver" # the process to check

processLocation = "/home/myusername/4990 dirserver" # the path to the application to open
application = "dirserver" # the name of the application to open

for line in os.popen("ps -A | grep " +processName):
       fields = line.split()
       pid = fields[0]
       if os.path.exists("/proc/" +pid) == False:
               os.popen(processLocation + application)
       elif os.path.exists("/proc/" +pid) == True:
               exit()

 

 

 

~/4990 dirserver$ ./dirserver.py

: command not founde 5:

import: unable to open X server `'.

import: unable to open X server `'.

: command not founde 8:

./dirserver.py: line 9: processName: command not found

: command not founde 10:

./dirserver.py: line 11: processLocation: command not found

./dirserver.py: line 12: application: command not found

: command not founde 13:

./dirserver.py: line 14: syntax error near unexpected token `('

'/dirserver.py: line 14: `for line in os.popen("ps -A | grep " +processName):

[»Lynx]

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processName = "dirserver" # the process to check

processLocation = "/home/myusername/4990 dirserver" # the path to the application to open
application = "dirserver" # the name of the application to open

for line in os.popen("ps -A | grep " +processName):
       fields = line.split()
       pid = fields[0]
       if os.path.exists("/proc/" +pid) == False:
               os.popen(processLocation + application)
       elif os.path.exists("/proc/" +pid) == True:
               exit()

 

 

 

~/4990 dirserver$ ./dirserver.py

: command not founde 5:

import: unable to open X server `'.

import: unable to open X server `'.

: command not founde 8:

./dirserver.py: line 9: processName: command not found

: command not founde 10:

./dirserver.py: line 11: processLocation: command not found

./dirserver.py: line 12: application: command not found

: command not founde 13:

./dirserver.py: line 14: syntax error near unexpected token `('

'/dirserver.py: line 14: `for line in os.popen("ps -A | grep " +processName):

 

Ehrm, afaik you can't ./ execute python scripts, you'll either need to use:

 

$ python script.py

 

from the terminal, or using crontab add the full path to the script, but check permissions to allow write/execute privileges.

 

Here's an example that I just tested to open ChatNut on my Mac:

 

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processName = "chatnut" # the process to check

processLocation = "/Users/cpburke/Downloads/" # the path to the application to open
application = "SignedChatnut.jar" # the name of the application to open

for line in os.popen("ps -A | grep " +processName):
fields = line.split()
pid = fields[0]
print pid
if os.path.exists("/proc/" +pid) == False:
	print "Process was not running, launching..."
	os.popen(processLocation + application)
elif os.path.exists("/proc/" +pid) == True:
	print "Process was running."
	exit()

[L.C.]

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processName = "dirserver" # the process to check

processLocation = "/home/bluetds2/4990_dirserver/" # the path to the application to open
application = "dirserver" # the name of the application to open

for line in os.popen("ps -A | grep " +processName):
       fields = line.split()
       pid = fields[0]
       if os.path.exists("/proc/" +pid) == False:
               os.popen(processLocation + application)
       elif os.path.exists("/proc/" +pid) == True:
               exit()

Does not seem to run, since the process does not appear under ps u. dirserver.py has a CHMOD of 755 (write access all the way). Running it with python dirserver.py.

[»Lynx]

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processName = "dirserver" # the process to check

processLocation = "/home/bluetds2/4990_dirserver/" # the path to the application to open
application = "dirserver" # the name of the application to open

for line in os.popen("ps -A | grep " +processName):
       fields = line.split()
       pid = fields[0]
       if os.path.exists("/proc/" +pid) == False:
               os.popen(processLocation + application)
       elif os.path.exists("/proc/" +pid) == True:
               exit()

Does not seem to run, since the process does not appear under ps u. dirserver.py has a CHMOD of 755 (write access all the way). Running it with python dirserver.py.

 

I guess in that case try:

 

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com

import os
import sys

processLocation = "/home/bluetds2/4990_dirserver/" # the path to the application to open
application = "dirserver" # the name of the application to open

for line in os.popen("ps -A | grep " +processLocation + application):
       fields = line.split()
       pid = fields[0]
       if os.path.exists("/proc/" +pid) == False:
               os.popen(processLocation + application)
       elif os.path.exists("/proc/" +pid) == True:
               exit()

Edited January 3, 2010 by Lynx

[L.C.]

bluetds2@krslynx:~/4990_dirserver$ python dirserver.py
bluetds2@krslynx:~/4990_dirserver$ ps u
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
bluetds2  7885  0.0  0.4   3296  1816 pts/1    Ss   00:01   0:00 -bash
bluetds2  8232  0.0  0.2   2304   904 pts/1    R+   02:45   0:00 ps u
bluetds2@krslynx:~/4990_dirserver$ python
Python 2.5.2 (r252:60911, Jan  4 2009, 17:40:26)
[GCC 4.3.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> dirserver.py
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError: name 'dirserver' is not defined

Same error with previous version of script.

Edited January 3, 2010 by L.C.

[»Lynx]

bluetds2@krslynx:~/4990_dirserver$ python dirserver.py
bluetds2@krslynx:~/4990_dirserver$ ps u
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
bluetds2  7885  0.0  0.4   3296  1816 pts/1    Ss   00:01   0:00 -bash
bluetds2  8232  0.0  0.2   2304   904 pts/1    R+   02:45   0:00 ps u
bluetds2@krslynx:~/4990_dirserver$ python
Python 2.5.2 (r252:60911, Jan  4 2009, 17:40:26)
[GCC 4.3.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> dirserver.py
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
NameError: name 'dirserver' is not defined

Same error with previous version of script.

 

In the terminal, type: ps -A | grep dirserver

 

That will show the output of the application, provided that it's actually called dirserver in the ps list, if that doesn't work type:

 

ps -A | grep /home/bluetds2/4990_dirserver/dirserver

 

which should defiantly show that it is running, provided it is actually running.

 

If that works, then type this into the terminal:

 

python /path/to/the/location/of/lc.py

 

Do not enter interpretational Python (You should not see >>> anywhere).

 

Edit: Seeing as you're running this on my server (I never noticed) - I'll test it myself.

 

Testing:

bluetds2@krslynx:~/4990_dirserver$ ps -A | grep dirserver                           
bluetds2@krslynx:~/4990_dirserver$ python /home/bluetds2/4990_dirserver/dirserver.py
Checking if dirserver is running...
-- Snrrrub's Directory Server 1.0 started --
Press CTRL+C to exit.
bluetds2@krslynx:~/4990_dirserver$ ps -A | grep dirserver
8584 pts/1    00:00:00 dirserver
bluetds2@krslynx:~/4990_dirserver$ python /home/bluetds2/4990_dirserver/dirserver.py
Checking if dirserver is running...
pid for dirserver is 8584
dirserver was running, goodbye!

 

Fully tested, it works.

Edited January 3, 2010 by Lynx

[»doc flabby]

LC i've got a script that does this already, that i use for ssdir.playsubspace.com...i don't want money if you choose this one its too simple to deserve it

 

It doesn't need a cron job either, it restarts the server as soon as it crashes...

 

#!/bin/bash
#change to dir server directory
cd ~/central   
for (( ; ; )) #repeat forever
do
 #run dir server
 mono Central.exe > logall.txt
done

Edited January 3, 2010 by doc flabby

[JoWie]

asss/scripts/run-asss is a good example that does this without cron

[L.C.]

Command: ps -A | grep dirserver

Result: 8584 pts/1 00:00:00 dirserver

 

Command: ps -A | grep /home/bluetds2/4990_dirserver/dirserver

Result:

 

Command: ps -A | grep "/home/bluetds2/4990_dirserver/dirserver"

Result:

 

Below I am testing to see how well the script functions when you are running multiple but different installations of the same software.

 

Dirserver A on port 4990 (Dirserver B is not running at this point)

Command: python /home/bluetds2/4990_dirserver/dirserver.py

Result: Checking if dirserver is running...

pid for dirserver is 8584

dirserver was running, goodbye!

 

Dirserver B on port 5768

Command: python /home/bluetds2/5768_dirserver/dirserver.py

Result: Checking if dirserver is running...

pid for dirserver is 8584

dirserver was running, goodbye!

 

Dirserver A on port 4990

Command: python /home/bluetds2/4990_dirserver/dirserver.py

Result: Checking if dirserver is running...

pid for dirserver is 8584

dirserver was running, goodbye!

 

 

 

LC i've got a script that does this already, that i use for ssdir.playsubspace.com...i don't want money if you choose this one its too simple to deserve it

 

It doesn't need a cron job either, it restarts the server as soon as it crashes...

 

#!/bin/bash
#change to dir server directory
cd ~/central   
for (( ; ; )) #repeat forever
do
 #run dir server
 mono Central.exe > logall.txt
done

bluetds2@krslynx:~/5768_dirserver$ ./auto

-bash: ./auto: /bin/bash^M: bad interpreter: No such file or directory

Edited January 3, 2010 by L.C.

[»Lynx]

You're not editing the script.

 

Here's the script simplified a bit more into functions/with full comments so you can understand how everything is working a little easier...

 

You can find this on your server at location "~/4990_dirserver/dirserver.py"

 

#/usr/bin/python
#Python Script for L.C.
#Saturday Jan 2nd 2010, 23:24
#by Christopher Burke krslynx@gmail.com
#2010/Jan/02 - Made edits, made it easier to understand

"""To Run This Script:
open utilities->terminal and execute:
$ python /path/to/this_script.py
You will need to check that processName variable matches the process
that you're _running_, and you will need to make sure that the correct
path to the process that you're trying to _run_ is located within the path
field on line 23"""

import os
import sys
import subprocess

processName = "dirserver" # the process to check

def runProcess(): # this function will run the below application
# If you want to change what application it opens, change the below path
subprocess.Popen(['/home/bluetds2/4990_dirserver/dirserver'])
# If you want a script that checks multiple directory servers
# (I've got no idea why you'd need this) then I guess that can be arranged.

def checkProcess(): 

""" This function will effectively run ps -A | grep <appname>
in the shell - therefore it will be checking if processName is running
so for multiple instances, you'll need to edit the processName variable
to the closest path possible."""

for line in os.popen("ps -A | grep " +processName):
	fields = line.split() # This is splitting the output of the above
	pid = fields[0] # and this is grabbing the leftmost output (pid)
	print "pid for", processName, 'is', pid # this is non-essential
	check = os.path.exists("/proc/" +pid) # this part of the script is
	# checking if a /proc/<pid> folder has been created (ie. if the proc-
	# ess exists)
	if check == True:
		# if the check is true...
		print processName, "was running, goodbye!" # it was running
		exit() # so exit
	else: # otherwise, run the runProcess function, found at line: 12
		runProcess()

"""MAIN"""
print "Checking if dirserver is running..." # This line is non-essential
checkProcess() # check process
runProcess() # run process, check process exits the script first anyway...

 

If you'd like to use doc_flabbys script, you'll need to edit the mono Central.exe > logall.txt line to execute dirserver instead.

[Simulacrum]

Lynx, I think that your script won't run ./ because the first line is missing a !

[L.C.]

# If you want a script that checks multiple directory servers

# (I've got no idea why you'd need this) then I guess that can be arranged.

I do not need a script for a specific application. The purpose of the script of my request is for general-purpose gameserver hosting. That means it should be a script that works for any application. It should be configurable to a specific gameserver application, in which it will monitor for.

 

Your script appears, to me, as if it were written for only 1 unique instance of a program. It would not work for general purpose because gameservers are generally expected to run multiple installations of the same program. I intend to use this script for anything-on-Linux gameserver hosting as a substitute for ServerDoc/TCAdmin -- neither of which really exist for Linux.

[»Lynx]

Lynx, I think that your script won't run ./ because the first line is missing a !

 

You're correct, good catch. If you edit line one to '#!/usr/bin/python' it will run by running /path/to/dirserver.py instead of python /path/to/dirserver.py. Thanks.

 

I do not need a script for a specific application. The purpose of the script of my request is for general-purpose gameserver hosting. That means it should be a script that works for any application. It should be configurable to a specific gameserver application, in which it will monitor for.

 

The script will check if the process is running, and if it's not execute a process. That is exactly what you requested - perhaps if you'd have been more explicit in your requests I wouldn't have needed to waste my time writing scripts that don't actually meet your requirements first time around.

 

Your script appears, to me, as if it were written for only 1 unique instance of a program. It would not work for general purpose because gameservers are generally expected to run multiple installations of the same program. I intend to use this script for anything-on-Linux gameserver hosting as a substitute for ServerDoc/TCAdmin -- neither of which really exist for Linux.

 

As I can't really be bothered to write something that's more intellegent in checking unique processes, I'll tell you that you can solve your issue of running multiple instances of the same software by running each (matching) process in a different user (you've got unlimited user-accounts on my server), then instead of using:

 

for line in os.popen("ps -A | grep " +processName):

 

use:

 

userName = bluetds2

for line is os.popen("ps --User " +userName +" | grep " +processName):

Edited January 3, 2010 by Lynx

[L.C.]

The script will check if the process is running, and if it's not execute a process. That is exactly what you requested - perhaps if you'd have been more explicit in your requests I wouldn't have needed to waste my time writing scripts that don't actually meet your requirements first time around.

Yes, you are right. This is my fault and I am sorry. I will pay you $5 as originally promised. Please inform me of your PayPal address. Edited January 4, 2010 by L.C.

[»Lynx]

I already said I'll do it for free. Message me if you have any issues with running multiple instances of the same application by running in different logins.

[»Maverick]

Hm Python.

I've got one for bash (/bin/sh) if you need it.

[Testtube]

monit anyone?

http://mmonit.com/monit/

Edited January 4, 2010 by Testtube

[»Maverick]

Coding yourself is way more cooler (and way more time consuming) haha