Multiple arguments in shell script using awk

Question

I've to make a script which will be able to sum the columns. The file looks like that:

1 2 3
1 2 
1

While executing script without the argument ./sum.sh I get the sum of all the columns so the answer is 10. But I have to make it add only certain columns. For example ./sum.sh 1 3 should sum first and third column and give 6.

My code:

sum=0

if [[ $# -eq 0 ]]; then
  awk '{for(i=1;i<=NF;i++) sum+=$i;}; END {print sum}' plik.txt
  else
    exit 0;
fi

while [ $# -gt 0 ]
do
    awk '{sum +="$1"} END {print sum}' plik.txt
    shift
done

I think that I'm quite close to the solution, but something must be missing.

There's a good solution here without using awk: stackoverflow.com/questions/33006845/… , If you are planning on doing such thing it might be better to let awk determine if there's one argument or more per line. — Yaron
– Yaron, Commented Dec 15, 2016 at 13:14
But I have to do it using awk. I know that this while chunk of code is not so bad but there is only a small part that I'm missing to achieve what I want. — mikro098
– mikro098, Commented Dec 15, 2016 at 13:16
The solution I provided doesn't print per line, if you want the sum to be calculated per line I need to make some small changes. — Yaron
– Yaron, Commented Dec 15, 2016 at 13:26

Kent · Accepted Answer · 2016-12-15 13:27:19Z

2

This one liner should work:

awk -v c="1 3" 'BEGIN{split(c,cols)}
               {for(x in cols)s+=$cols[x]}END{print "Sum:"s}' file

Note the c="1 3" means the columns you want to do sum, space separated. It could be set by shell script variable: -v c="$var", the awk will do the calculation and output.

With your example file, the above one-liner outputs:

Sum:6

answered Dec 15, 2016 at 13:27

Kent

197k36 gold badges248 silver badges317 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

mikro098 Over a year ago

it works but I was hoping for minor upgrade of what I posted using shift.

Kent Over a year ago

@codddeer123 you don't need shift, just gather all the parameter, and build the a b c d string, and pass to the awk line

mikro098 Over a year ago

I came up with something like this: while [[ $# -gt 0 ]] do awk -v x="$1" '{sum +=$x} END {print sum}' plik.txt shift done and after executing ./sum.sh 1 2 it returns 3 and 4 so it adds up first and second column. How to add them together and get the final answer?

Kent Over a year ago

@codddeer123 read my comment above, "you don't need the shift"

karakfa · Accepted Answer · 2016-12-15 18:43:33Z

1

here is a combination of your script and Kent's solution

#!/bin/bash

file=plik.txt

if [ $# -eq 0 ];
    then
        awk     '{for(i=1;i<=NF;i++) sum+=$i} 
             END {print sum}' "$file"
    else
        awk -v cols="$*" 'BEGIN {split(cols,cs)}
                                {for(c in cs) sum+=$cs[c]}
                          END   {print sum}' "$file"    
fi

in action

$ ./sum.sh 1
3

$ ./sum.sh
10

$ ./sum.sh 1 3
6

$ ./sum.sh 1 2
7

$ ./sum.sh 1 2 3 4
10

$ ./sum.sh 1 2 3
10

answered Dec 15, 2016 at 18:43

karakfa

67.8k8 gold badges45 silver badges59 bronze badges

Comments

Yaron · Accepted Answer · 2016-12-15 13:24:06Z

0

This is what I came up with, no bash conditions required:

awk 'BEGIN{sum=0} {if(NF==1) sum+=$1;else for(i=1;i<=NF;i++) sum+=$i;} END{print sum}' plik.txt

answered Dec 15, 2016 at 13:24

Yaron

1,2411 gold badge15 silver badges36 bronze badges

3 Comments

mikro098 Over a year ago

./sum.sh 3 returns 10 and ./sum.sh 2 also returns 10 so it doesn't work. I has to sum only certain columns as I mentioned. ./sum.sh 1 3 should add up first and third column of plik.txt file

Yaron Over a year ago

What do I do in a case that a column does not exist?

mikro098 Over a year ago

hmm, script can exit with info about not correct argument but for now I only want to sum chosen columns.

Collectives™ on Stack Overflow

Multiple arguments in shell script using awk

3 Answers 3

4 Comments

Comments

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

4 Comments

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related