Tested in bash and bash2

Parameter assignment in loop is not exported out of the loop if read is used see script.
Same error occures if read is used in combinatie with pipe eg. 
tail -n 1 x2 | read p1 p2.
No assignment to parameters read take place.


#!/bin/bash2
echo "1" > x2
echo "2" >> x2
echo "Error parameter not exported"
d=""
cat x2|while read p1
do
 echo "d1 = $d"
 d="${d}${p1}"
 echo "d2 = $d"
done
echo "d3 = $d"

echo ""
echo "No Error parameter is exported"
d=""
set $(cat x2)
while [ $# -ne 0 ]
do
 p1=$1
 shift 1
 echo "d1 = $d"
 d="${d}${p1}"
 echo "d2 = $d"
done
echo "d3 = $d"