oh-my-bash/completions/ssh.completion.sh

#! bash oh-my-bash.module
# Bash completion support for ssh.

_omb_module_require lib:omb-completion

function _omb_completion_ssh {
  local cur
  _omb_completion_reassemble_breaks :

  local -a options
  if [[ $cur == *@*  ]] ; then
    options=(-P "${cur%%@*}@" -- "${cur#*@}")
  else
    options=(-- "$cur")
  fi

  local IFS=$'\n'

  local -a config_files=()
  local base_config_file
  for base_config_file in ~/.ssh/config /etc/ssh/ssh_config; do
    # parse all defined hosts from config file
    if [[ -r $base_config_file ]]; then
      local basedir
      basedir=${base_config_file%/*}
      config_files+=("$base_config_file")

      # check if config file contains Include options
      local -a include_patterns
      _omb_util_split include_patterns "$(awk -F' ' '/^Include/{print $2}' "$base_config_file" 2>/dev/null)" $'\n'
      local i
      for i in "${!include_patterns[@]}"; do
        # relative or absolute path, if relative transforms to absolute
        [[ ${include_patterns[i]} == /* ]] || include_patterns[i]=$basedir/${include_patterns[i]}
      done

      # interpret possible globbing
      local -a include_files
      _omb_util_glob_expand include_files '${include_patterns[*]}'
      local include_file
      for include_file in "${include_files[@]}";do
        # parse all defined hosts from that file
        [[ -s $include_file ]] && config_files+=("$include_file")
      done
    fi
  done
  if ((${#config_files[@]} != 0)); then
    COMPREPLY+=($(compgen -W "$(awk '/^Host/ {for (i=2; i<=NF; i++) print $i}' "${config_files[@]}")" "${options[@]}"))
  fi

  local -a known_hosts_files=()
  local known_hosts_file
  for known_hosts_file in ~/.ssh/known_hosts /etc/ssh/ssh_known_hosts; do
    if [[ -r $known_hosts_file ]]; then
      known_hosts_files+=("$known_hosts_file")
    fi
  done
  if ((${#known_hosts_files[@]} != 0)); then
    COMPREPLY+=($(compgen -W "$(awk '
      $1 !~ /^\|/ {
        gsub(/[][]|[,:].*/, "", $1);
        if ($1 !~ /ssh-rsa/) print $1;
      }' "${known_hosts_files[@]}")" "${options[@]}"))
  fi

  # parse hosts defined in /etc/hosts
  if [[ -r /etc/hosts ]]; then
    COMPREPLY+=($(compgen -W "$(grep -v '^[[:space:]]*$' /etc/hosts | grep -v '^#' | awk '{for (i=2; i<=NF; i++) print $i}' )" "${options[@]}"))
  fi

  _omb_completion_resolve_breaks
}

complete -o default -o nospace -F _omb_completion_ssh ssh scp