Here is that kind of script:
#!bin/bash
# Checking parameters number, we need two parameters
if [ $# -ne 1 ]
then
echo "Wrong number of parameters, please try again."
exit 1
fi
# Checking if number is odd or even
if [ $[$1 % 2] -eq 0 ]
then
echo "Even"
# Write number to even.txt file
echo $1 >> even.txt
else
echo "Odd"
# Write number to odd.txt file
echo $1 >> odd.txt
fi
exit 0
This bash script accepts one parameter - number and if number is even it is written into end of even.txt file and if odd into odd.txt.