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Shell Programming and Scripting

alternate rows of a file

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# 1  
Old 08-25-2007
alternate rows of a file
hi all
is there any process in which i can get alternate rows of a file.i want to do further processing on those alternate rows.i want to select row1,row3,row5.... like this from a file.
# 2  
Old 08-25-2007
You can do something like that :
Code:
awk 'NR%2' inputfile

Jean-Pierre
# 3  
Old 08-25-2007
You can get this way
a=0
for file in `cat inputfile`
do
a=`expr $a + 1`
even=`expr $a%2|bc`
if [ $even -gt 0 ]
then
echo $file
fi
done
# 4  
Old 08-25-2007
You can also do :
Code:
odd=0
while read line
do
   odd=`expr 1 - $odd`
   if [ $odd -ne 0 ]
   then
      echo $line
   fi
done < inputfile

Jean-Pierre.
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