ssh-copy-id.sh

#!/bin/sh

usage () {
	echo "Usage: $0 [-i [identity_file]] [user@]machine"
	exit 1
}

# Parse options
while getopts ":i:" o
do	case "$o" in
	i)	# Identity file specified
		if [ $(($OPTIND-1)) -eq $# ] # if there's no other argument after this one
		then 
			# Make sure last argument is not a file or folder to catch this case where no host is provided:
			# 	ssh-copy-id -i [identity_file]
			[ ! -f "$OPTARG" ] || usage 
			[ ! -d "$OPTARG" ] || usage 
			# If last argument is not a file, read the default key and continue
			key=`cat "$HOME/.ssh/id_rsa.pub"` #
		else # read specified identity
			[ -f "$OPTARG" ] || usage
			key=`cat "$OPTARG"`
		fi;;
	[?]) usage;;
	esac
done
[ $# -gt 0 ] || usage
shift $(($# - 1))

# Show usage if no host given
host=$1
if [ -z "$host" ] 
then
	usage
fi

# Default to `ssh-add -L` if no -i option given
if [ -z "$key" ]
then
	key=`ssh-add -L`
fi

echo "Uploading private key..."
ssh $host 'mkdir -pm 700 ~/.ssh; echo ' $key ' >> ~/.ssh/authorized_keys ; chmod 600 ~/.ssh/authorized_keys'
echo "Done."
exit 0