zsh/Completion/User/_ssh

#compdef ssh slogin scp ssh-add ssh-agent ssh-keygen

_remote_files () {
  # This is extremely simple-minded; could parse "ls -F" output to do
  # colorings and LIST_TYPES and so on, but I'm just not that ambitious.
  compadd $(ssh ${words[CURRENT]%:*} echo ${words[CURRENT]#*:}\*)
}

_ssh () {
  local curcontext="$curcontext" state lstate line ret=1 expl args tmp
  typeset -A opt_args

  args=()

  # ssh-opt is a pseudo-command used to complete ssh options for `scp -o'.

  case "${words[1]:t}" in
  ssh|slogin)
    args=(
      ':remote host name:->userhost'
      '(-):command: _command_names -e'
      '*::args:->command'
    )
    ;&
  ssh-opt)
    _arguments -C -s \
      '-a[disable forwarding of authentication agent connection]' \
      '-c[select encryption cipher]:encryption cipher:(idea des 3des blowfish arcfour tss none)' \
      '-e[set escape character]:escape character (or `none'"'"'):' \
      '(-n)-f[go to background]' \
      '-i[select identity file]:SSH identity file:_files' \
      '-k[disable forwarding of kerberos tickets]' \
      '-l[specify login name]:login name:_ssh_users' \
      '-n[redirect stdin from /dev/null]' \
      '*-o[specify extra options]:option string:->option' \
      '-p[specify port on remote host]:port number on remote host:' \
      '-q[quiet operation]' \
      '-P[use non priviledged port]' \
      '-t[force pseudo-tty allocation]' \
      '-v[verbose mode]' \
      '-V[show version number]' \
      '-x[disable X11 forwarding]' \
      '-C[compress all data]' \
      '-L[specify local port forwarding]:local port forwarding:->forward' \
      '-R[specify remote port forwarding]:remote port forwarding:->forward' \
      "$args[@]" && ret=0

    while [[ -n "$state" ]]; do
      lstate="$state"
      state=''

      case "$lstate" in
      option)
        if compset -P '*[= ]'; then
          case "$IPREFIX" in
          *(#i)(batchmode|compression|fallbacktorsh|forward(agent|x11)|keepalive|passwordauthentication|rhosts(|rsa)authentication|rsaauthentication|usersh|kerberos(authetication|tgtparsing)|usepriviledgedport)*)
	    _wanted values expl 'truth value' compadd yes no && ret=0
            ;;
          *(#i)cipher*)
	    _wanted values expl 'encryption cipher' \
                compadd idea des 3des blowfish arcfour tss none && ret=0
            ;;
          *(#i)globalknownhostsfile*)
            _description files expl 'global file with known hosts'
            _files "$expl[@]" && ret=0
            ;;
          *(#i)hostname*)
	    _wanted hosts expl 'real host name to log into' _ssh_hosts && ret=0
            ;;
          *(#i)identityfile*)
            _description files expl 'SSH identity file'
            _files "$expl[@]" && ret=0
            ;;
          *(#i)(local|remote)forward*)
            state=forward
            ;;
          *(#i)proxycommand*)
            compset -q
            shift 1 words
            (( CURRENT-- ))
            _normal && ret=0
            ;;
          *(#i)stricthostkeychecking*)
            _wanted values expl 'checking type' compadd yes no ask && ret=0
            ;;
          *(#i)userknownhostsfile*)
            _description files expl 'user file with known hosts'
            _files "$expl[@]" && ret=0
            ;;
          *(#i)user*)
	    _wanted users expl 'user to log in as' _ssh_users && ret=0
            ;;
          *(#i)xauthlocation*)
            _description files expl 'xauth program'
            _files "$expl[@]" -g '*(-*)' && ret=0
            ;;
          esac
        else
          _wanted values expl 'configure file option' \
              compadd -M 'm:{a-z}={A-Z}' -S '=' - \
                  BatchMode ClearAllForwardings Cipher Compression \
                  CompressionLevel Host ConnectionAttempts EscapeChar \
                  FallBackToRsh ForwardAgent ForwardX11 \
                  GlobalKnownHostsFile HostName IdentityFile KeepAlive \
                  KerberosAuthentication KerberosTgtPassing LocalForward \
                  NumberOfPasswordPrompts PasswordAuthentication Port \
                  ProxyCommand RemoteForward RhostsAuthentication \
                  RhostsRSAAuthentication RSAAuthentication \
                  StrictHostKeyChecking TISAuthentication \
                  UsePriviledgedPort User UserKnownHostsFile UseRsh \
                  XAuthLocation && ret=0
        fi
        ;;
      forward)
        if compset -P 1 '*:'; then
          if compset -P '*:'; then
            _message 'port number'
          else
	    _wanted hosts expl host _ssh_hosts -qS:
          fi
        else
          _message 'listen-port number'
        fi
        return
        ;;
      command)
        shift 1 words
        (( CURRENT-- ))
        _normal
        return
        ;;
      userhost)
        if compset -P '*@'; then
	  _wanted hosts expl 'remote host name' _ssh_hosts && ret=0
        else
          if (( $+opt_args[-l] )); then
	    tmp=()
	  else
	    tmp=( 'users:login name:_ssh_users -qS@' )
	  fi
	  _alternative \
	      'hosts:remote host name:_ssh_hosts' \
	      "$tmp[@]" && ret=0
        fi
        ;;
      esac

      break;
    done

    return ret
    ;;
  scp)
    _arguments -C -s \
      '-c[select encryption cipher]:encryption cipher:(idea des 3des blowfish arcfour tss none)' \
      '-P[specify port on remote host]:port number on remote host:' \
      '-i[select identity file]:SSH identity file:_files' \
      '-S[specify path to ssh]:path to ssh:_files -g \*\(-\*\)' \
      '-o[give SSH options]:options:->options' \
      '-p[preserve modification times]' \
      '-r[recursively copy directories]' \
      '-v[verbose mode]' \
      '-B[batch mode]' \
      '-C[compress data]' \
      '*:file:->file' && ret=0

    if [[ "$state" = options ]]; then
      compset -q
      words=(ssh-opt "$words[@]" )
      (( CURRENT++ ))
      _ssh
      return
    elif [[ -n "$state" ]]; then
      if compset -P '*:'; then
        _remote_files && ret=0
      elif compset -P '*@'; then
        _wanted hosts expl host _ssh_hosts -S: && ret=0
      else
        _alternative \
	    'files:: _files' \
	    'hosts:host:_ssh_hosts -S:' \
	    'users:user:_ssh_users -S@' && ret=0
      fi
    fi
    return ret
    ;;
  ssh-add)
    _arguments -s \
      '-p[read passphrase from stdin]' \
      '-l[list all identities]' \
      '-d[remove identity]' \
      '-D[delete all identities]' \
      '*:SSH identity file:_files'
    return
    ;;
  ssh-agent)
    _arguments -s \
      '(:)-k[kill agent automatically]' \
      '(:)-s[force sh-style shell]' \
      '(:)-c[force csh-style shell]' \
      '*::command: _normal'
    return
    ;;
  ssh-keygen)
    _arguments \
      '(-p -c -u -P)-b[specify number of bits in key]:bits in key:' \
      '(-p -c)-f[key file]:key file:_files' \
      '(-c -u)-N[specify new passphrase]:new passphrase:' \
      '(-b -u -f)-P[specify old passphrase]:old passphrase:' \
      '(-p -u)-C[specify new comment]:new comment:' \
      '(-b -f -C -u -c)-p[change passphrase of private key file]' \
      '(-b -f -N -p -u)-c[change comment in private and public key files]' \
      '(-b -N -C -p -c)-u[change key cipher to default]'
    return
    ;;
  esac
}

_ssh_users () {
  _combination -s '[:@]' my-accounts users-hosts users "$@"
}

_ssh_hosts () {
  if [[ "$IPREFIX" == *@ ]]; then
    _combination -s '[:@]' my-accounts users-hosts "users=${IPREFIX/@}" hosts "$@"
  else
    _combination -s '[:@]' my-accounts users-hosts \
      ${opt_args[-l]:+"users=${opt_args[-l]:q}"} hosts "$@"
  fi
}

_ssh "$@"