邮件存储文件循环脚本

#!/bin/sh
help()
{
cat<
this is a help document
HELP
exit 0
}
error()
{
echo -n  "$1"
echo "Your input have a error"
exit 1
}
while [ -n "$1" ]; do
case $1 in
-h) help; shift 1;;
--) break;;
-*) echo "error";;
*) break;;
esac
done
#main
if [ -z "$1" ]; then
error
fi
filen="$1"
#REname
for n in 9 8 7 6 5 4 3 2 1; do
if [ -f "$filen.$n" ]; then
p=` expr $n + 1`
mv $filen.$n  $filen.$p
fi
done
if [ -f "$filen" ]; then
mv $filen $filen.1
fi
touch $filen