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AWK inside For loop

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# 1  
Old 04-20-2011
Power AWK inside For loop
Hi,
Code:
awk -F"|" 'BEGIN{sum=0}{sum+=$2}END{printf("%d\n", sum)}' css.txt 
awk -F"|" 'BEGIN{sum=0}{sum+=$3}END{printf("%d\n", sum)}' css.txt 
awk -F"|" 'BEGIN{sum=0}{sum+=$4}END{printf("%d\n", sum)}' css.txt 
awk -F"|" 'BEGIN{sum=0}{sum+=$5}END{printf("%d\n", sum)}' css.txt 
awk -F"|" 'BEGIN{sum=0}{sum+=$6}END{printf("%d\n", sum)}' css.txt

The above code is working fine. Instead of using it, if I use the following for loop, nothing is getting printed. Please advice.
Code:
for i in 2 3 4 5 6  
do 
awk -F"|" 'BEGIN{sum=0}{sum+=$i}END{printf("%d\n", sum)}' css.txt 
done

Moderator's Comments:
Mod Comment
Please use code tags when posting data and code samples!
Last edited by thulasidharan2k; 04-20-2011 at 01:05 PM.. Reason: code tags, please!
# 2  
Old 04-20-2011
I can't imagine the above code would work 'fine'. It's all on one big line with no delimiters so would try to run it as one giant statement.

As for why the second doesn't work:
1) You missed an f in 'for'.
2) You missed several important ; or newlines.
3) The shell never substitutes anything inside '' quotes. awk provides a way to input variables instead.

Code:
for i in 2 3 4 5 6
do
        awk -v I=$i -F"|" 'BEGIN{sum=0}{sum+=$I}END{printf("%d\n", sum)}' css.txt
done

# 3  
Old 04-20-2011
You need some "special" quoting here:
Code:
for i in 2 3 4 5 6;  do awk -F"|" 'BEGIN{sum=0}{sum+='"$i"'}END{printf("%d\n", sum)}' css.txt; done

If you donīt quote the command correctly, the shell will not substitute the i variable inside the awk command, because nothing inside single quotes is substituted. Also, beware that there are missing semi-colons in your for loop structure.
Last edited by Franklin52; 04-20-2011 at 12:52 PM.. Reason: Please use code tags, thank you
# 4  
Old 04-20-2011
Hi All,

Thanks for your quick suggestions. The below codes are working...

Code:
for i in 2 3 4 5 6;  do awk -F"|" 'BEGIN{sum=0}{sum=sum+$'$i'}END{printf("%d\n", sum)}' css.txt; done

or
Code:
for i in 2 3 4 5 6;  do awk -F"|" 'BEGIN{sum=0}{sum=sum+$('$i')}END{printf("%d\n", sum)}' css.txt; done

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