Hi,
Thanks fro your answer, but i 've still a problem !!!

it-s whith ksh (the problem is ok with zsh, but zsh have problem with 
arrays (i've programs to prove it !)

The value next the loop is the same than before the loop, and not the 
value at the end of the loop !!!

Try this  short program, it count normally the number of file in a 
directory (ls |wc -l equivalent), I use this structure in multiple shells 
to administrate Oracle databases, and i'm very embarassed !!!

thanks to help me (sorry for my poor english)

gbouchez

#!/bin/ksh
a=0
echo $a
ls  | while read FILE
do
   let a=a+1
   echo $a
done
echo 'end of loop'
echo $a

Thanks...