while loop read mystery

[Allasso]

This really has me stumped: First script gives the expected output, however when I change the nested loop from a "for" loop to a "while" loop, observe what happens to the count output:

#!/bin/bash

count=1

for line in one two threeXfour fiveXsix seven eight
do

echo "$line" | grep "X" > /dev/null
if [ $? == 0 ]
then
var=`echo "$line" | sed 's/X/\n/g'`
for line2 in $var
do
echo $count
let count=count+1
echo $line2
done
else
echo $count
let count=count+1
echo $line
fi

done

#output:

1
one
2
two
3
three
4
four
5
five
6
six
7
seven
8
eight



When reading from a "while" loop, output is as follows:


#!/bin/bash

count=1

for line in one two threeXfour fiveXsix seven eight
do

echo "$line" | grep "X" > /dev/null
if [ $? == 0 ]
then
echo "$line" | sed 's/X/\n/g' | \
while read line2
do
echo $count" " > /dev/stderr
let count=count+1
echo $line2
done
else
echo $count" " > /dev/stderr
let count=count+1
echo $line
fi

done

#output

1
one
2
two
3
three
4
four
3
five
4
six
3
seven
4
eight


Anyone know why?

[nmset]

Piping to a while loop makes the loop to run in a sub-shell. There was a discussion about it on this forum recently, I can't trace it back. You can get more info here :
Variable Scope in Bash (NuclearDonkey.net)

[Allasso]

aaahhh, thanks.