Hi

The next script campares two files File1-Line1 vs File2-Line1, File1-Line1 vs File2-Line2... only if line contains "AS-", if LineX is not in File2 writes in aux, but "valor" is allways=1 never changes! What is wrong?
valor changes to 0 before break, after brake is again 1

#!/bin/ksh

echo > aux

while read label
do
valor=1
echo $label | grep "AS-"
if [ $? -eq 0 ]
then
while read labelold
do
if [ "${label}" = "${labelold}" ]
then
#echo "encon" >aux2
valor=0
echo $valor
break
fi
echo $valor #<--- Allways is 1
done < hosts.old
if [$valor -eq 1]
then
echo "$label" >> aux
fi
fi
done < hosts

Whenever you pipe things into a loop, that loop becomes its own process, with it's own seperate process space -- which inherits variables you already have, but things it sets don't propogate back.

You can write the variable into a file in the loop

#!/bin/ksh

echo > aux

while read label
do
   valor=1
   echo $label | grep "AS-"
   if [ $? -eq 0 ]
   then
      while read labelold
      do
         if [ "${label}" = "${labelold}" ]
         then
            #echo "encon" >aux2
            valor=0
            echo $valor
            break
         fi
         echo $valor #<--- Allways is 1
      done < hosts.old
      if [$valor -eq 1]
      then
         echo "$label" >> aux
      fi
   fi
done < hosts