assign value to variable is not working

Shell Programming and Scripting
1

Hi :slight_smile:

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! :confused: 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 $valor #<--- Allways is 1 :confused:
done < hosts.old
if [$valor -eq 1]
then
echo "$label" >> aux
fi
fi
done < hosts

2

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.

3

You can write the variable into a file in the loop

4 
#!/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

After assigning the value 0 to your variable, you break the while loop so you never display the variable with the new value 0.

Whith KSH the modification of variable inside loops aren't lost (that is not the case with bourne shell).
Try the following script:

[CODE]var=init
ls | while read file
do
var="Last file is $file"
done

Jean-Pierre.