Trying to count # of times an 'if' statement is true in a loop.

new2bash · 02-26-2015, 02:02 PM

I just have no idea how to do what I'm looking for here. I have a simple script (see below) that pings a list of sites from a separate text file. I want to count how many times the pings fail -per site-. I understand how to count total failures, but I have no clue how to keep the count separate for each site.

Bash script

Code:

#!/bin/bash

for i in {1..3600}
do
clear ; echo -e "Interval $i"

while IFS=, read name ip
do

ping -c 1 $ip >/dev/null 2>&1

if [ $? -ne 0 ] ; then
                echo -e "\e[31;1mName: $name\t$ip  \t- down.\e[0m\tCount: ___"

        else

                echo -e "\e[32;1mName: $name\t$ip  \t- up!\e[0m\tCount: ___"
fi

done < ~/monitor.txt

#  30 sec Countdown Timer
for i in {30..1};do echo -ne "\r$i" && sleep 1;echo -ne "\r   "; done

done

Sample csv text file

Code:

google,8.8.8.8
nat,10.1.1.1

Sample Output My goal is to have "Count ___" = the number of times site x failed.
http://i.imgur.com/Jwd2YRW.png

grail · 02-27-2015, 12:12 AM

Assuming recent version of bash (4+) you could use associative arrays:

Code:

declare -A count

echo $((count[name]++))

This is assuming your variable called 'name'

new2bash · 04-01-2015, 06:08 AM

Quote:

Originally Posted by grail

Assuming recent version of bash (4+) you could use associative arrays:

Code:

declare -A count

echo $((count[name]++))

This is assuming your variable called 'name'

Thanks, but where would I add this?

I don't see how this adds to "count" only when a test(ping) fails, or how it keeps a separate tally for each item in the list. I've tried googling around for the answer and have hit a brick wall.

pan64 · 04-01-2015, 06:28 AM

what do you want to count? You need to insert it next to the echo ... down line I think.

new2bash · 04-01-2015, 06:33 AM

Quote:

Originally Posted by pan64

what do you want to count? You need to insert it next to the echo ... down line I think.

As the OP states, I am trying to count the number of times the test(ping) fails for each item(IP) in the test list. I need the counts to be separate.

For example
Name: google 8.8.8.8 - Up! Count: 0
Name: nat 10.1.1.1 - down. Count: 2

*Count should only increment on fails.

pan64 · 04-01-2015, 06:36 AM

I think you misunderstood my question: You need to insert that line exactly where you want to count something...

new2bash · 04-01-2015, 06:46 AM

Quote:

Originally Posted by pan64

I think you misunderstood my question: You need to insert that line exactly where you want to count something...

Here's how the script reads with that addition...

Code:


#!/bin/bash

# Declare 'count' array.
declare -A count

for i in {1..3600}
do
clear ; echo -e "Interval $i"

while IFS=, read name ip
do

ping -c 1 $ip >/dev/null 2>&1

if [ $? -ne 0 ] ; then
                echo -e "\e[31;1mName: $name\t$ip  \t- down.\e[0m\tCount: $((count[name]++))"

        else

                echo -e "\e[32;1mName: $name\t$ip  \t- up!\e[0m\tCount: $((count[name]))"
fi

done < ~/monitor.txt

#  30 sec Countdown Timer
for i in {30..1};do echo -ne "\r$i" && sleep 1;echo -ne "\r   "; done

done

Only the "down"(fail) line adds to the count. However this only has one(1) counter. There are multiple IP's being tested and ALL fails are being added together. I need them in increment separately.

Current output (assuming "nat" fails 3 times out of 10...and "google" never fails)
Name: google 8.8.8.8 - Up! Count: 3
Name: nat 10.1.1.1 - down. Count: 3

What I need is:
Name: google 8.8.8.8 - Up! Count: 0
Name: nat 10.1.1.1 - down. Count: 3

pan64 · 04-01-2015, 07:04 AM

try to use two arrays: $((count_up[name]++)) and also count_down

michaelk · 04-01-2015, 07:20 AM

Quote:

$((count[name]++))

name in this context is a constant and not a variable.

Try
$(( count[$name]++ ))

grail · 04-01-2015, 09:34 AM

If you are not interested in the up count and wish this to always be zero, then do not include the counter in the up portion just us a static zero.
Of course if you are interested in both up and down, then pan64's suggestion is the way to go.

@michaelk - did you try it? I think you will find that like inside (()) when a variable is inside [] for an array it is actually evaluated.

oops ... apologies michaelk, I forgot this was an associative array and not a numeric one ... you are correct that it needs the $ to draw the string from it

michaelk · 04-01-2015, 09:58 AM

Code:

#!/bin/bash
declare -A count

name=me

echo $(( count[name]++ ))

name=foo
echo $(( count[name]++ ))


echo "count[me]" $(( count[me] ))
echo "count[foo]" $(( count[foo] ))
echo "count[name]" $(( count[name] ))
echo

name=me

echo $(( count[$name]++ ))

name=foo
echo $(( count[$name]++ ))

echo

echo "count[me]"  $(( count[me] ))
echo "count[foo]" $(( count[foo] ))
echo "count[name]" $(( count[name] ))

Code:

0
1
count[me] 0
count[foo] 0
count[name] 2

0
0

count[me] 1
count[foo] 1
count[name] 2

Or did I miss something...

michaelk · 04-01-2015, 10:32 AM

In addition adding first as below will display the actual error count as the OP posted the script.

$(( ++count[$name] ))

grail · 04-02-2015, 12:30 AM

Quote:

Originally Posted by michaelk

Or did I miss something...

Yes ... my apology

new2bash · 04-02-2015, 01:10 AM

This must be a lot harder than I expected as none of these seem to resolve the question.

new2bash · 04-02-2015, 01:21 AM

I'm trying to make my question as simple as possible as I'm assuming people just aren't understanding the desired outcome.

1) The script reads a text(CSV) list of names and IP's.
2) The first IP on the list is pinged.
3)
---a--- IF down the script prints "Name <ip> - down Count: 1
---b--- IF up, the script prints "Name <ip> - up Count: 0
* 0 fails so far
4) The script now pings the next IP on the list.
---a--- IF down the script prints "Name <ip> - down Count: 1
---b--- IF up, the script prints "Name <ip> - up Count: 0
The screen now looks like this (assuming the 1st IP was up and the 2nd was down)
Name: google 8.8.8.8 - up! Count: 0
Name: nat 10.1.1.1 - down. Count: 1

5)A brief countdown occurs then the screen clears and the script starts the ping tests again.

* With the changes recommended above I now get...
Name: google 8.8.8.8 - up! Count: 1
Name: nat 10.1.1.1 - down. Count: 2

See the problem? It's combining ALL fails. I need them separate. The desired output would look like this (assuming the 1st item continues passing and the 2nd continues to fail)

Name: google 8.8.8.8 - up! Count: 0
Name: nat 10.1.1.1 - down. Count: 8