les: ls if it's a directory, less if it's a file

les.sh

#!/bin/sh
set -e
if [ $# -eq 0 ]; then
        >&2 echo "No argument given, using ls"
        exec ls
elif [ -d "$1" ]; then
        >&2 echo "Directory detected, using ls"
        exec ls "$1"
elif [ -f "$1" ]; then
        >&2 echo "File detected, using less"
        exec less "$1"
else
        >&2 echo "No such file or directory"
        exit 1
fi