Validating commandline argument

Shell Programming and Scripting
1

Hi,
I am calling a script script2.shl from script1.shl as below

script2.shl "TABLE_NAME" -r 10

In that I have to validate the parameter 4.

i.e : it should be only 10 20 30 40 50

I know that I can do it by checking like below

if [[ $4 -eq 10 -o $4 -eq 20 -o $4 -eq 30 -o $4 -eq 40 -o $4 -eq 50 ]]; then
 echo "TRUE"
else
  echo "FALSE"
fi

But my question here is, can I check all these in a single statement and not like giving "-o" for each value.

2 
case $4 in
     [12345]0) echo true;;
     *) echo false;;
esac
3

Use the below if condition.

if [ `sed '/^[1-5]0/!d' <<<$4` ]
then
         echo "TRUE"
else
           echo "FALSE"
fi
4

The external command (sed) is slow and unnecessary.

The "here string" (<<<) is not portable.

That test will succeed even if $4 is 1000.