CODEWITHSUNDEEP
shellunixawk
user2268507
user2268507

Reputation:

Addition and Multiplication of items in a single line with shell script

I currently have a variable `$var1' that contains the following:

4 -38 2 -42 1 -43 10 -44 1 -45 6 -46 1 -48 1 -49

I want to add 50 and then multiply by 2 for every second number. That is,

(-38 + 50) * 2 = 24

(-42 + 50) * 2 = 16

I would then want to replace -38 with 24 and -42 with 16. How should I go about doing this?

Would you do this with awk? If so, how do you cycle through the each item in a single line? I see awk can loop through rows but haven't seen an example of looping through items on a line.

Thanks for your help.

Upvotes: 0

Views: 95

Answers (2)

Ed Morton
Ed Morton

Reputation: 204055

$ echo "$var1" | awk '{for (i=2;i<=NF;i+=2) $i=($i+50)*2}1'
4 24 2 16 1 14 10 12 1 10 6 8 1 4 1 2

Upvotes: 1

Ashish Gaur
Ashish Gaur

Reputation: 2050

Try this : 

echo $var | awk -F" " '{ for (i=1; i<=NF; i++) if(i%2 == 0) printf "%d ",( $i + 50 ) * 2 ; else printf "%d ",$i  }'

Upvotes: 2

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