@ 260802.2
current
#!/bin/sh

set -e

if [ $# != 2 ]; then
    echo "Usage: $(basename "$0") ssh-private-key-path pass-key-path" >&2
    exit 1
fi

sshkey="$1"
passkey="$2"
runner="$(ssh-gen-askpass-runner "$passkey")"
display=dummy
if [ -n "$DISPLAY" ]; then
    display="$DISPLAY"
fi

SSH_ASKPASS="$runner" DISPLAY="$display" ssh-add "$sshkey" < /dev/null
rm "$runner"