SSH access scripts generator

ssh-amazon-scripts.bash

#!/bin/bash

postfix="0"
username=ec2-user
if [ $# -lt 2 ]; then
	echo "Usage: $0 <IP> <key file> [<postfix> [<username>]]"
	exit 1
else
	if [[ ! $1 =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}$ ]]; then
		echo "IP \"$1\" has incorrect format"
		exit 1
	fi
	echo "IP: $1"
	if [ ! -f $2 ]; then
		echo "WARNING: key \"$2\" does not exist!"
	fi
	echo "key file: $2"
	ip=$1
	key_file=$2
	if [ $# -gt 2 ]; then
		postfix=$3
	fi
	if [ $# -gt 3 ]; then
		username=$4
	fi
	file_connect="connect-$postfix.sh"
	file_upload="upload-$postfix.sh"
	file_download="download-$postfix.sh"
	if [ -f $file_connect ]; then
		echo "\"$file_connect\" exists, exiting"
		exit 2
	fi
	if [ -f $file_upload ]; then
		echo "\"$file_upload\" exists, exiting"
		exit 2
	fi
	if [ -f $file_download ]; then
		echo "\"$file_download\" exists, exiting"
		exit 2
	fi
fi

# connect
echo -e "#!/bin/bash\n\nssh -i $key_file $username@$ip\n" > $file_connect

# upload
echo -e '#!/bin/bash\n\nif [ $# -ne 2 ]; then\n\tdst=`basename $1`\nelse\n\tdst=$2\nfi\n\n' > $file_upload
echo -e "scp -i $key_file -r \$1 $username@$ip:\$2" >> $file_upload

# download
echo -e "scp -i $key_file -r $username@$ip:\$1 \$2" > $file_download

chmod a+x $file_connect
chmod a+x $file_upload
chmod a+x $file_download