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Hi

i have centos 5.3 installed on server i want to write a script which will check dns ips i.e 214.253.255.231 and 214.253.255.236 is pinging continously if both ips are not pinging then i want to run another .sh file can you pls assist me in same

What do you want to achieve from this? Whats the purpose?

amartlk,
what exactly do you want to accomplish ?
1) do you want both ip's to be pinged by another one ?
2) OR both ip's should ping each other ?

I would like to help provided you give more details !!

regards,
nm

Hi

these are the 2 dns ips address of isp i want only ping this 2 ips should ping from my server if both are not pinged the i run one sh file which we restart adsl and my net is working now i do it manually

Please show us what code you've done so far

Code:

ping -c1 <ip> || FixTheInternet.sh

expanded

Code:

ping -c1 <ip> || dns1=1 && dns1=0

ping -c1 <ip2>|| dns2=1 && dns2=0

(( "$dns1" == "0" && "$dns2" == "0" )) || FixTheInterWebs.sh

Thanks for reply
it is ok as below where below are 2 ip of dns
ping -c1 <214.253.255.231> || dns1=1 && dns1=0
ping -c1 <214.253.255.236>|| dns2=1 && dns2=0
(( "$dns1" == "0" && "$dns2" == "0" )) || FixTheInterWebs.sh

no, remove < and >

<ip> and <ip2> were intended as 'markers'

Code:

ping -c1 214.253.255.231 || dns1=1 && dns1=0

ping -c1 214.253.255.236 || dns2=1 && dns2=0

(( "$dns1" == "0" && "$dns2" == "0" )) || FixTheInterWebs.sh

you will still need to do some work for that to do what you want

while I'm at it,
a re-write

Code:

for ip in 214.253.255.231 214.253.255.236;do

    ping -c1 $ip || ( FixTheInterWebs.sh; break )

done

does the same, but less 'messing about'

#!/bin/bash

for ip in 214.253.255.231 214.253.255.236;
do
ping -c1 $ip || ( FixTheInterWebs.sh; break )
done

is this correct now

@amartlk: Have you tried running Firerat's examples?

The only way to learn anything is to try to understand what's going on and play around with the given examples.

If there's something specific about the code you don't understand we can/will explain it to you.

Hi

ya i want to understand the flow of code thats why i ask you

Quote:

Originally Posted by amartlk (Post 5063046)

ya i want to understand the flow of code thats why i ask you

Which example and what part are you unclear about?

Quote:

Originally Posted by amartlk (Post 5063024)

#!/bin/bash

for ip in 214.253.255.231 214.253.255.236;
do
ping -c1 $ip || ( FixTheInterWebs.sh; break )
done

is this correct now

well, the script is ok,, but my logic is broken

the examples I have given are not difficult

lets ignore the second one for now, and look at what the first is doing

Code:

ping -c1 214.253.255.231 || dns1=1 && dns1=0

# if ping ( with count of 1 , so only one ping ) 214.253.255.231 returns a none-zero  exit (error ) set variable  dns1 to 1

# if exit is 0 ( no error ) set variable  dns1 to 0

# repeat with second ip , var is dns2

(( "$dns1" == "0" && "$dns2" == "0" )) || FixTheInterWebs.sh

# if var dns1 AND dns2 are both 0 return 'true'

# if either dns1 or dns2 are not zero return 'false'

# || ( action if false )

alternative

Code:

ping -c1 214.253.255.231;dns1=$?

ping -c1 214.253.255.236;dns2=$?

if (( "$dns1" != "0" && "$dns2" != "0" )); then

    FixTheInterWebs.sh

fi

there is not much else I can type about this
there are a number of ways to do it

anyway, back to my broken logic

Code:

for ip in 214.253.255.231 214.253.255.236;

do

    ping -c1 $ip || ( FixTheInterWebs.sh; break )

done

this is broken as it will run FixTheInterWebs.sh if 214.253.255.231 is 'down' even if 214.253.255.236 'up'
you want to Fix the Interwebs if both dns servers are 'down'