near real time if script

[segment]

Hey all, need advice on something...

Have machine A and machine B. Both have to monitor a specific term and react. Its being run from cron (*/1 * * * * /run/this/command)...

Machine B needs to tail -f /var/log/messages for the field "is dead" then react:

tail -f /var/log/messages|grep "is dead" &> /dev/null
if [ "$?" != true ]
then
/run/this/command
fi


Any suggestions?

perl -e 'print $i=pack(c5,(40*2),sqrt(7600),(unpack(c,Q)-3+1+3+3-7),oct(104),10,oct(101));'

 

[KenCunningham]

Segment - pardon me for asking, but what's the question?

I don't mind people who aren't what they seem. I just wish they'd make their mind up.

 

[segment]

Dur... My question was dumb I figured what I needed to out however this is my new question (let me make sure I type it as a question this time)

I'd like to be able to react at the following:

ps -ax|awk '/program_name/{print $5}'|sed -n '1p'

The output of this would be:

# ps -ax|awk '/program_name/{print $5}'|sed -n '1p'
/sbin/program_name

What I'd like to do is run this from cron on an "if" statement basis.

If ps -ax|awk '/program_name/{print $5}'|sed -n '1p' sees program_name do nothing, if it doesn't see something then it needs to run /sbin/program_name

perl -e 'print $i=pack(c5,(40*2),sqrt(7600),(unpack(c,Q)-3+1+3+3-7),oct(104),10,oct(101));'

 

[feherke]

Hi

Is faster and uses less resources if you use less pipes & programs. You not need to precess the entire list then use [tt]sed[/tt]. If you need one line, then [tt]exit[/tt] from [tt]awk[/tt] after the first match.

ps -ax|awk '/program_name/{print $5[red];exit[/red]}'

Anyway, I am happy to see that you gave up at least with [tt]tail[/tt]. ;-)

My [tt]ps[/tt] is able to :

-C select by command name

So I can do :

ps -C program_name || program_name &

Feherke.

http://rootshell.be/~feherke/

 

[segment]

I can ps -C program_name|awk '{print $4}'|sed -n '2p' to get program_name but I need to watch every x or so minutes and if its running do nothing if not, run program_name. This is where I'm stuck...

Something like:

RUNNING=`ps -C program_name|awk '{print $4}'|sed -n '2p'`

while [ "$RUNNING" != program_name ]

if [ "$RUNNING" -eq program_name ]
then
/sbin/program_name
fi

exit 0

perl -e 'print $i=pack(c5,(40*2),sqrt(7600),(unpack(c,Q)-3+1+3+3-7),oct(104),10,oct(101));'

 

[feherke]

Hi

ps -C program_name[red][s]|awk '{print $4}'|sed -n '2p'[/s][/red]

You not need to filter the output of [tt]ps[/tt], because it sets the exit code : if any program with the given name is runnig, then 0, else not 0.

So the only thing you need to do is to execute that program if [tt]ps[/tt] returns non 0 exit code :

ps -C program_name || program_name &

Feherke.

http://rootshell.be/~feherke/

 

[segment]

Dur!!!!!!!!!!!!!!!!!!! Feherke you pimp. See maybe I should actually start reading instead of skimming :| *bows*

perl -e 'print $i=pack(c5,(40*2),sqrt(7600),(unpack(c,Q)-3+1+3+3-7),oct(104),10,oct(101));'

 

[feherke]

Hi

And I should actualy start testing before posting.

Without braces ( {} ) the shell will push the entire line into background :

ps -C program_name || { program_name & }

Feherke.

http://rootshell.be/~feherke/