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Linux: Process file in reverse

Posted on 2013-11-18
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Last Modified: 2013-11-18
This returns the number 200 just as it should, because there are 200 lines in the file:
#!/bin/bash
while read MONTH DAY TIME DATA
do
 COUNT=$((COUNT+1))
done < $1
echo $COUNT

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When I try to do this in reverse it returns 1.
#!/bin/bash
while read MONTH DAY TIME DATA
do
 COUNT=$((COUNT+1))
done <<< $(tac $1)
echo $COUNT

Open in new window

I am using CentOS.
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Question by:hankknight
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Accepted Solution

by:
woolmilkporc earned 500 total points
ID: 39657358
#!/bin/bash
while read MONTH DAY TIME DATA
do
 COUNT=$((COUNT+1))
done <<< "$(tac $1)"
echo $COUNT

Open in new window


i.e. put quotes around "$(tac $1)", otherwise the newlines will be stripped. I didn't take this into account (I simply forgot about this behaviour) in my comments to your previous threads. Sorry!
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LVL 16

Author Closing Comment

by:hankknight
ID: 39657381
Thanks!  That explains everything.
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