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I'm trying to get the sum, 36962, to echo with $TOTAL at the end of the script, but I cannot get it to work. Any advice? This is for a school project and I am pretty rusty with Bash.

TOTAL=0
while read p; do
    awk '{ if ($1 > 100 ) print TOTAL+=$1}'
    echo $TOTAL
done < ipuniq.txt
  • 6578
  • 6723
  • 32735
  • 36962
  • ECHOS -> 0
Joshua Trimm
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  • bash and awk are 2 completely separate, independent tools and you wouldn't write a loop using bash to call awk one line at a time, you'd just do it all in awk (see why-is-using-a-shell-loop-to-process-text-considered-bad-practice). Post some concise, testable sample input and expected output if you'd like help. – Ed Morton Nov 16 '19 at 19:25
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    Thank you for educating me on the differences.between awk and bash. Had no clue about that. – Joshua Trimm Nov 17 '19 at 22:31
  • You can do this with awk only. awk '$1 > 100 { sum+=$1 } END { print sum }' Awk is perfectly suited for these tasks – Valentin Bajrami Nov 17 '19 at 22:33
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    Please don't post pictures of text. People answering the question will almost always use that input to actually test their answer and since you are asking people for a favor it's more polite to allow them to copy and paste rather than have to retype from an image. You can select a block of text and press ctrl + k to make a code block or surround it with ``` – jesse_b Nov 17 '19 at 22:49

1 Answers1

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The TOTAL variable is a shell variable and therefore awk won't know about it. In your awk command the TOTAL variable is unset in each iteration so it's being reset with a single value each time and then printed.

Additionally, it seems pointless to use awk in a loop like this.

awk can perform this operation by itself with the following 1 liner:

awk '$1 > 100 { total+=$1 } END { print total }' ipuniq.txt

No loops or other commands needed.

However, if your assignment requires you use bash/shell you could do:

total=0
while read -r p _; do
    ((p>100)) && total=$((total+p))
done < ipuniq.txt
echo "$total"

This will use a shell arithmetic expression to check if the value of p is greater than 100, if so it will add it to total.

Additionally note: I have added the -r option to your read command as this will print backslashes literally (likely unnecessary for your use case but I prefer to use -r at all times unless I specifically have a reason not to.)

I have also added the _ parameter name, this will prevent p from being set to an undesirable input. read will assign all leftover words to the last parameter, so in your case say your file contains numbers and IPs like:

1 10.10.10.10
2 10.10.10.11

Without a parameter to catch the cruft, p would be set to:

p='1 10.10.10.10'

then:

p='2 10.10.10.11'
Jeff Schaller
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jesse_b
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    I put the echo "$total" outside of the loop and it worked great! Thank you so much for the help! – Joshua Trimm Nov 17 '19 at 22:29
  • @JoshuaTrimm: ah, I wasn't sure what your intent was and thought you wanted to print the current total on each iteration. I have updated my answer to reflect. – jesse_b Nov 17 '19 at 22:41
  • @JoshuaTrimm wrt I put the echo "$total" outside of the loop and it worked great! - you shouldn't be doing that at all, you should be using the awk-only script. – Ed Morton Nov 17 '19 at 23:23
  • How do I get the IP address with the loop? I know how to get the number and add the total. But I need to the ip address with another list of ips.... – Joshua Trimm Nov 18 '19 at 00:04