Script to tell whether any of it's argument repeats

cycled.sh

#! /bin/sh

# If no arguments are given, return true.

if [ $# -eq 0 ]
then
	exit 0
fi

# Test whether any of the arguments repeats.

while [ $# -gt 0 ]
do
	_CURRENT="$1"
	shift
	for _ITEM in "$@"
	do
		if [ "$_CURRENT" = "$_ITEM" ]
		then
			exit 0
		fi
	done
done

# If not, return false.

exit 1