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Assigning variables in a bash for loop

Hey all-
I'm running a for loop in bash that grabs the DNS address of a remote server. Most of the time, there is more than one running. I want to write a for loop that will cycle through and assign the DNS addresses to variable names that can be called later in the script. Here's what I've got so far:

Code:

count=0

for address in $(ec2din --simple | awk '$2 ~ /running/ {print $3}');

do

  count=`expr $count + 1`

  echo $count

  address"$count"="$address" #This line is the meat of my question

  rsync -e "ssh -i `echo ~`/.ec2/gsg-keypair" -avz /home/admin/data root@${address}:/root

  scp -i ~/.ec2/gsg-keypair ~/Kai-script root@${address}:/root

done

This runs fine, but when I try to call one of the values $address(insertnumberhere), it just comes up as blank on the terminal and doesn't evaluate to anything in a call. In addition, the echo in line 5 also is blank, even though I know it has a value. I've tried a few different varieties of statements in the line in question... any ideas why this isn't assigning correctly?

Cheers,
Jarrod

address"$count"="$address" #This line is the meat of my question

In your line above isn't address a variable? Should it have $ in front of it?

Also, try ((count++)) notation. I try to avoid `expr $x + 1` notation.

You need to read the bash beginners tutorial and the bash
advanced scripting guide my friend. address in the for
loop is *not* an array variable; the for loop will assign
the resulting values from your

Code:

ec2din --simple | awk '$2 ~ /running/ {print $3}'

one at a time, and repeat the loop for them one by one.

All you need is

Code:

for address in $(ec2din --simple | awk '$2 ~ /running/ {print $3}');

do

  rsync -e "ssh -i `echo ~`/.ec2/gsg-keypair" -avz /home/admin/data root@${address}:/root

  scp -i ~/.ec2/gsg-keypair ~/Kai-script root@${address}:/root

done

Cheers,
Tink

I've been reading them, Tink, and they do clarify, but even in their example I get the same issue. It's trying to evaluate the variable setting as a bash command, rather than just setting an environment variable. Perhaps I wasn't clear, I know how the for loop assigns the variables, the scp and rsync could basically not be there. I want to be able to address each instance separately and transfer different files, etc., later in the script *not in a for loop*. Here's the example script from the advanced bash scripting guide

Code:

#!/bin/bash

count=0

for planet in Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto

do

  count=`expr $count + 1`

  echo $planet

  PLANET"$count"=$planet

done

echo $PLANET1

echo $PLANET2



exit 0

yields this output:

Code:

Mercury

forloop: line 7: PLANET1=Mercury: command not found

Venus

forloop: line 7: PLANET2=Venus: command not found

Earth

forloop: line 7: PLANET3=Earth: command not found

Mars

forloop: line 7: PLANET4=Mars: command not found

Jupiter

forloop: line 7: PLANET5=Jupiter: command not found

Saturn

forloop: line 7: PLANET6=Saturn: command not found

Uranus

forloop: line 7: PLANET7=Uranus: command not found

Neptune

forloop: line 7: PLANET8=Neptune: command not found

Pluto

forloop: line 7: PLANET9=Pluto: command not found

So the expression is coming up correctly using the $planet, but it's not setting the variable like it should be. That's my specific hang up here.

One more attempt, now that I read your explanation again...

In the assignment:

address$count=$address

the shell has problems with having left and right side having substitution requests.

Try the following:

eval address$count=\$address

This forces a double scan.

It might help if you try using a true array, rather than just a variable with a number attached. Also, choose a name for the array that's different from the for loop variable. Here's a simple example:

Code:

#!/bin/bash



count=0



for entry in Fry Leela Bender Nibbler; do



  array[$count]="$entry"

  ((count++))



done



echo "array entry 0 is: ${array[0]}"

echo "array entry 1 is: ${array[1]}"

echo "array entry 2 is: ${array[2]}"

echo "array entry 3 is: ${array[3]}"

echo "the total array is: ${array[@]}"

Both of those options work great! The array might be a touch better just so they're all in one place, but that will be great. Thanks guys!