Transfers your public SSH key (id_rsa.pub) to the authorized_keys file of a remote computer, allowing for password-less login.

ssh-transfer-key.sh

#!/usr/bin/env bash

PROGRAM_NAME=`basename $0`

ARGS=`getopt u:H:h "$@"`
KEY_PATH=~/.ssh/id_rsa.pub

if [ $? != 0 ] ; then
    echo "Error parsing arguments. Try $PROGRAM_NAME -h" > /dev/stderr
    exit 2
fi

eval set -- "$ARGS"
while true; do
    case $1 in
        -u)
            SSH_USER="$2"; shift 2; continue
        ;;
        -H)
            SSH_HOST="$2"; shift 2; continue
        ;;
        -h)
                BA="\033[1m"
                BD="\033[0m"
                UA=`tput smul`
                UD=`tput rmul`

                echo "$PROGRAM_NAME"
                echo ""
                echo -e "${BA}USAGE${BD}"
                echo -e "    $PROGRAM_NAME [${BA}-h${BD}] [${BA}-u${BD} ${UA}username${UD}] [${BA}-H${BD} ${UA}host${UD}] [${UA}[user@]host${UD}] [${UA}path to key${UD}]"
                echo ""
                echo -e "${BA}GENERAL${BD}"
                echo "    Transfers your public SSH key (id_rsa.pub) to the authorized_keys file of a remote computer, allowing for password-less login."
                echo ""
                echo -e "${BA}OPTIONS${BD}"
                echo -e "    ${BA}-u${BD} ${UA}username${UD}"
                echo "          Username on host"
                echo ""
                echo -e "    ${BA}-H${BD} ${UA}host${UD}"
                echo "          Remote hostname"
                echo ""
                echo -e "    ${BA}-h${BD}    Display help"
                echo ""
                exit 0
        ;;
        --)
                # no more arguments to parse
                shift
                break
        ;;
        *)
                printf "Unknown option %s\n" "$1"
                exit 1
        ;;
    esac
done

# (Try to) determine where to connect (and which key to transfer)
if [ $# -gt 0 ] ; then
    #SITE=`echo $(pwd)/"$1"`

    if [ -z "$SSH_HOST" ] ; then
        SSH_STRING=$1
    fi

    if [ $# -gt 1 ] ; then
        KEY_PATH=$2
    else
        if [ -n "$SSH_HOST" ] ; then
            KEY_PATH=$1
            SSH_STRING=""
        fi
    fi
fi

# Still don't know where to connect, ask for it!
if [ -z "$SSH_STRING" ] && [ -z "$SSH_HOST"] ; then
    while :
    do
        read -p "Host: " SSH_HOST

        if [ -n "$SSH_HOST" ] ; then
            break
        fi
    done
fi

# No [user@]host given, let's start with the -H arg
if [ -z "$SSH_STRING" ] ; then
    SSH_STRING="$SSH_HOST"
fi

# Now, if there is still no user part in the SSH_STRING, lets add the -u arg
if [ -n "$SSH_STRING" ] && [ -n "$SSH_USER" ] && [[ "$SSH_STRING" != *@* ]] ; then
    SSH_STRING="$SSH_USER@$SSH_STRING"
fi

# Alright, this should not be possible. But better safe than sorry, as they say
if [ -z $SSH_STRING ] ; then
    echo "No host given. Try $PROGRAM_NAME -h" > /dev/stderr
    exit 2
fi

# Dinally! Let's transfer that key
echo `cat $KEY_PATH` | ssh "$SSH_STRING" "mkdir -p ~/.ssh; cat >> ~/.ssh/authorized_keys;"