Print directory tree structure

trees.sh

#!/bin/sh
# 1st sed: remove colons
# 2nd sed: replace higher level folder names with dashes
# 3rd sed: indent graph three spaces
# 4th sed: replace first dash with a vertical bar
if [ $# -eq 1 ]; then
    ls -R $1 | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/  /' -e 's/-/|/'
elif [ $# -gt 1 ]; then
    echo "Only one directory at a time please!!"
    exit 255
else
    echo "Please provide a directory to display tree structure"
    echo "Usage: ./tree.sh <dir>"
    exit 1
fi

exit