error while using "while"

[buptjiwei]

I wrote codes blow and sth wrong reported

cat file.txt | while read line
do
    echo $line
done

while is not recognized as an internal or external command......

and also

for ff in `ls *`; do echo $ff;done

reported "ff was unexpected at this time"

which is ok in redhat shell, so how should i make it work,thx