Unix Scripting

A question...

I'm looking for some way to to automate the following process..

I've written a very simple script that runs four instances of the ps -ef |grep -i xxxx command with different xxxxs ( i.e. search strings ) in each line. The output of this, ofcourse is a listing of all these processes running with xxxx included.

My problem is the following:

I need to be able to a) Set a timer that will let the script be run autiomatically every say 20 minutes.
and b) I need to be able to set a check, returning a confirmation message as to whether the process xxxx is running or not ( as opposed to a listing of the processes ) Meaning, if the process xxxx IS running, I get an echo saying "Process xxxx is up and running".

I've been thinking of later incorporating a menu, that will allow me to check each process one by one based on user choice, but first this is more necessary. Any help will be appreciated.

Cheers

hmm, one sort of complicated way to do this i'm sure someone else will have an easier method.

Automate your script by using a cron job. Make your script post to a log with a time-date stamp for everytime it writes to the log. Create a second program that reads the entries of the log (importance of time-date stamp) every 5 min or something.

This second prgram could print to the screen the log entries. The second program would be pretty simple, a little file IO is all there is too it. I'm sure theere is an easier way, but with my experience this is how I would do it.

DeafLamb

forgot to mention something. might be important.

The environment I'm running this script on is a highly critical one, meaning I cannot afford to screw up even in the slightest. I probably won't have the priviledges to either.

DeafLamb - I thought about your idea too, but couldn't venture into it too much because I don't have much experience with cron jobs. I'll have to tinker with it on my home box maybe, but I can't here. Thanks though. heh.

Any help / code / ideas will be great, guys and girls

Cheers

edit:
Is there any file searching tool in Unix or Linux that does NOT display the text once it's been found? The grep family, by default, will display the line once it is found. I am looking for a method that will just search a file, and return whether the search was successful or not.. instead of displaying the result on screen.

I would use "at" to save it to a file and then echo it back out.

take a look at this file from this website...

IMHO the ultimate guide to BASH shell programming..

Quote:

---

Is there any file searching tool in Unix or Linux that does NOT display the text once it's been found? The grep family, by default, will display the line once it is found. I am looking for a method that will just search a file, and return whether the search was successful or not.. instead of displaying the result on screen.

---

From "man grep".

-q, --quiet, --silent -q, --quiet, --silent
Quiet; do not write anything to standard output. Exit immedi-
ately with zero status if any match is found, even if an error
was detected. Also see the -s or --no-messages option.

Well goddammit. I searched the manual pages of grep.. didn't see that, owensleftfoot. hehe thats what happens when you're working 14 hour graveyard shifts. grrr! Thanks for all the help guys. I still have no idea how to set a default timer on it ( execute every 20 mins or so )

The basic idea is that after the ps -ef |grep -i xxxx spews out it's output, I just want to check whether the grep command was successful ( i.e. string was matched or not ) and if it was, display the message "Process XXXX is up and running" instead of displaying the actual process instance from the ps command on screen. i could post the code of my script, if anyone would like to take a look, and maybe suggest something?

Thanks for the link JinX :)

Cheers

ps -ef | grep -i xxxxx | grep -v grep
echo $?

$? = 0 if match found
$? = 1 if match not found
$? = 2 if error

Do not run any other commands or pipes before you check, $? gets changed after every command. If you need to store the value to check later, assign it (a=$?).

/nebulus

woo woo, thanks nebulus :) heh, i'll check to see if this can be integrated with my bit of useless scripting, and get back to you guys.

By the way, my mood is about the same as yours, neb.. and for the exact same reasons.

You could try something this (This will write to standard output):
#!/bin/sh
while true
do
ps -ef | grep --silent <string you are looking for> | grep -v grep
if [ "$?" = 0 ]; then
echo "Process <string you are looking for> is up and running"
else echo "Process <string you are looking for> is boned"
fi
sleep 600
done

Where <string you are looking for> is the string you are looking for

cpid.sh (simple script to do check for any process):

Code:

---

#!/bin/sh

if [ ! "$1" ]; then
        echo "Usage: cpid <process>"
        exit 2
fi

a=`ps -ef | grep -i $1 | grep -v grep | grep -v cpid`
if [ $? = 0 ]; then
        exit 0                           
else
        exit 1
fi

---

Add entry to your cronjob:
0,20,40 * * * * `<pathtocpid>/cpid <process>`; if [ $? = 0]; then <dowhateverprocessrunning>; else <dowhateverprocessnotrunning>; fi

Ie,

Code:

---

0,20,40 * * * * `/bin/cpid syslogd`; if [$? = 0]; then echo "Process is running"; else echo "Process is not running"; fi

---

Note, you will probably not want to echo from cron but do something else, maybe pipe it to sendmail or something or maybe restart it...

/nebulus

Well, thanks a bunch guys. I managed to do it ( get the script working I mean ). The method I used was simpler than ( IMHO ) the ones suggested by neb and Bart.

Code:

---

if
 /usr/xpg4/bin/grep -i -q xxxx pm.txt
then
 echo "The process xxxx is:  Up and Running!"
else
 echo "The process xxxx is:  Not Running!"
fi
echo

---

Basically, pm.txt is the output of the ps -ef |grep -i xxxx command (its a required file, so I thought I'd use it. I couldve gone the other way and searched the actual ps output on screen, but since the file is there... and is updated each time, why not use it, right?). Searching through the file, I find the desired string xxxx. I've specified -q which hides the output, yet returns the status of the command to be successful. It can only be used with the /usr/xpg4/bin/grep version of grep, mind you.

The remaining echos are self-explainatory. :rolleyes:

heh, crappy, I know.. but it works. :) yay!
Now for the cron jobs!

would this be considerd a script?
i put this in a file called general-install

./configure
make
make install

somethimes i hate having to stick around for a file to install cause they can take a while so il copy this to the directory and cd there then type ./general-install and im set

You may want to start a new thread, but yes, it's a script.

Now instead of a script, what about :
./configure && make && make install

"make" will be executed only if "./configure" returns zero (true), and "make install" will be executed only if "make" returns zero. Then you don't have to wait for each command to complete to type in the next command.

If "./configure" completes successfully, and "make" fails, you can do the necessary changes and type:
make && make install

Peace always,
<jdenny>