how to do the sum of 2 columns adding that into new column by reading the csv file in shell script-CodePudding

I'm trying to implement shell script to read csv file and do the sum of 2 columns and adding into new column called total. But it's not successfully done. please suggest how can I achieve this.

my input csv file

a,b,c
1,2,3
4,5,6

expected output

a,b,c,total
1,2,3,5
4,5,6,11

Here a is a primary key

I tried below code to achieve this

echo "First arg: 1"
awk "{print $3 $2 """""" $1}"
echo "First arg: 2
awk -F, "{$(NF 1)=Null;}1" OFS=, file.csv
awk -F "," "{print $1,$2,$3,$2 $3}"

my output is:

C:\Users\inrenan\NIFI\NIFI-1~1.2-B\NIFI-1~1.2>awk -F "," "{print $1,$2,$3,$2 $3}" 
a b c 0
1 2 3 5
4 5 6 11

only I'm facing the issue is column name

CodePudding user response：

This is the awk script you need:

BEGIN{ FS=OFS="," } { print $0, (NR==1 ? "total" : $2 $3) }

Do whatever magical incantation you have to to use it in Windows.

In Unix you'd just do:

awk 'BEGIN{ FS=OFS="," } { print $0, (NR==1 ? "total" : $2 $3) }' input
a,b,c,total
1,2,3,5
4,5,6,11

but I hear Windows has some odd quoting rules that are best avoided and so the common advice I see given for Windows is to save the script in a file named, say, script.awk (which you could also do in Unix) and invoke it as:

awk -f script.awk input
a,b,c,total
1,2,3,5
4,5,6,11

Based on the last script in your question, this might work for you in Windows but I really don't know Windows quoting rules:

awk "BEGIN{ FS=OFS=\",\" } { print $0, (NR==1 ? \"total\" : $2 $3) }" input

CodePudding user response：

For a very cumbersome one-liner:

awk -F',' '{if (NR==1) {printf "%s,total\n",$0;} else {sum=0; for(i=2; i<=NF; i  ) {sum  =$i}; {printf "%s,%s\n",$0,sum;}}}' file.csv

CodePudding user response：

With your shown samples, please try following awk program. Here mentioning an awk variable named fields which has value of 2,3 we could mention field numbers there separated by , and it will take care of taking sum of all those fields.

awk -v fields="2,3" '
BEGIN{
  FS=OFS=","
  num=split(fields,arr,",")
  for(i=1;i<=num;i  ){
    field[arr[i]]
  }
}
FNR==1 { print $0,"total"; next }
FNR>1{
  sum=0
  for(i=1;i<=NF;i  ){
    if(i in field){ sum =$i }
  }
  $(NF 1)=sum
}
1
'  Input_file