add_github_keys.sh

#!/usr/bin/env bash
p() {
  echo "$@" >&2
}


test -z "$USERNAME" && USERNAME=$1

test -z "$USERNAME" && {
  p "Usage: $0 <github_username>"
  p "Alternatively, pass USERNAME (github username) in as an environment variable"
  p "e.g. curl script.sh | env USERNAME=bigboi69 bash"
  exit 1
}
GITHUB_KEYS="$(curl https://github.com/$USERNAME.keys | cut -d' ' -f1,2)"

if test -e ~/.ssh/authorized_keys; then
  EXISTING_KEYS="$(cat ~/.ssh/authorized_keys | cut -d' ' -f1,2)"
else
  EXISTING_KEYS=""
fi

p "Adding github keys to authorized keys."
printf "%s\n" "$EXISTING_KEYS" "$GITHUB_KEYS" | sort -u > ~/.ssh/authorized_keys