Show count and instance IDs of existing EC2 instances in all regions of AWS:

I'm kicking myself for not posting this earlier in my past life-- but here's a handy shell script that can list the number of instances in each region in AWS.

Show count and instance IDs of existing EC2 instances in all regions of AWS:

Single line:

Set my AWS profile to my personal account rather than work.  
To setup, use aws --profile personal configure   

$ export aws_profile=personal

If the buffer space can handle long entries, you can run this in a single line, otherwise there's a multi line below to run as a script.

$ for i in $(aws --profile $aws_profile ec2 describe-regions --output json | grep "RegionName" | cut -d '"' -f4 | sort); do export buf=$(aws --profile $aws_profile ec2 --region $i describe-instances --output json | grep InstanceId | cut -d '"' -f4); export buf_num=$(echo $buf | grep -c .); echo "=== $i -> $buf_num instance(s) ===";echo $buf ; done

Multi Line:

Good for placing into a script to run, also listed this way for readability:

#!/bin/bash export aws_profile=personal for i in $(aws --profile $aws_profile ec2 describe-regions --output json| grep "RegionName" | cut -d '"' -f4 | sort); do export buf=$(aws ec2 describe-instances \ --profile $aws_profile \ --region $i \ --output json | \ grep InstanceId | \ cut -d '"' -f4); export buf_num=$(echo $buf | grep -c .); echo "=== $i -> $buf_num instance(s) ==="; echo $buf; done

Sample Output:

=== ap-northeast-1 -> 0 instances === === ap-northeast-2 -> 0 instances === === ap-south-1 -> 0 instances === === ap-southeast-1 -> 0 instances === === ap-southeast-2 -> 0 instances === === ca-central-1 -> 0 instances === === eu-central-1 -> 0 instances === === eu-north-1 -> 0 instances === === eu-west-1 -> 0 instances === === eu-west-2 -> 0 instances === === eu-west-3 -> 0 instances === === sa-east-1 -> 0 instances === === us-east-1 -> 0 instances === === us-east-2 -> 0 instances === === us-west-1 -> 0 instances === === us-west-2 -> 1 instances === i-012345678901234ab

Multiply / Sum column data in awk/sed

Sourced from here:
http://unix.stackexchange.com/questions/115998/how-do-i-multiply-and-sum-column-data-using-awk-and-or-sed

I have several columns of data. I always have the same number of rows (say 5). In the 2nd column, I want to multipy the first value by 5, then the second value by 4, the third value by 3, etc. I then want to sum these values, and divide by the sum of the values in the second column. How would I do this in sed and/or awk?

Example:

4 5 7 1 2 3
5 1 2 3 1 2
4 2 3 6 1 2
3 4 1 6 3 3
2 3 1 2 1 6

Answer: (5*5 + 4*1 + 3*2 + 2*4 + 1*3)/(5 + 1 + 2 + 4 + 3) = 3.067

Solution 1:

Replace 6 with total (number of lines + 1) if needed:

awk '{mult+=$2*(6-NR); sum+=$2;} END {print mult/sum;}' yourfile.txt 

Displays: 3.06667

Solution 2:

If in case total number of lines are not known

$ cat file
4 5 7 1 2 3
5 1 2 3 1 2
4 2 3 6 1 2
3 4 1 6 3 3
2 3 1 2 1 6

$ awk 'FNR==NR{t = NR+1;next}{mult+=$2*(t-FNR);sum+=$2} 
       END{print mult/sum}' file{,}
3.06667

Explanation

awk 'FNR == NR{t=NR+1;next}

FNR variable --> Current line number in the current file

NR variable-->The total number of lines seen so far

The condition FNR == NR can only be true while awk is reading the first file of argument

t=NR+1 --> variable t holds line count +1 extra since it's required in our current context

next--> Stops the processing of the current input record and proceeds with the next input record

mult+=$2*(t-FNR) --> variable mult holds some of (5*(t-FNR) + ..... + 4*1 + 3*2 + 2*4 + 1*3)

sum+=$2 --> variable sum holds sum of column2

END--> AnEND rule is executed, once, after all the input has been read

print mult/sum --> Finally print mult/sum

file{,} --> you can also file file file but i used shortcut this bash trick you can say, try echo file{,} and echo file{,,} on your terminal.