#!/bin/sh
#
# $Id: rshall 807 2011-08-19 08:22:04Z rp $

# rshall: rsh with multiple hosts, *last* arg is command
# with -i, also accepts input ... I'd rather dup stdin or so, but how?

# tmpfile
tmpfile=/tmp/rshall-$$

rm='/bin/rm'

# error handling
trap "$rm"' -f $tmpfile; exit' 1 2 3 4 13 15

PATH=/usr/tuelocal/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/usr/etc; export PATH

#host=host
#finger=finger
grep=grep
cat=cat
sed=sed
rsh=ssh

#--- cmdline parsing ---#
#

Puke()
{
  if [ -n "$*" ]; then echo Fatal error: $* 1>&2; fi
  $cat <<ZZ 1>&2

Usage:
  $0 [-v] [-i] [-e] [-b] [-u user] [-H] [-Y] [-P] host1 [host2 [...]] "command"

  to issue "rsh host command" for every host

  use -i flag to supply input, -e to redirect stderr to stdout,
    -v for progress messages, -b to start in the background,
    -u user to connect as the given user,
    -H to check the hostnames with 'host',
    -Y to check them with 'ypmatch',
    -P to check them with 'ping'

  note: the effect of -i is to call rsh without the -n flag
  take care: -b may fill up your process table if used on many hosts

ZZ

  exit 1
}

input=
hostlist=
verbose=
bg=
check_w_host=
check_w_ypmatch=
check_w_ping=
user_prefix=

while :
do
  case "$1" in
    -h|-help|\?*) Puke;;
    -b) bg=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -i) input=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -v) verbose=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -e) errtoout=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -u) shift; user_prefix="$1@"
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -H) check_w_host=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -Y) check_w_ypmatch=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -P) check_w_ping=1
	if [ -n "$command" ]; then Puke "options must precede arguments"; fi;;
    -*) Puke "$1 is not a valid option" ;;
    "") break;;
    *) hostlist="$hostlist $command"; command=$1;;
  esac
  shift
done

if [ -z "$command" ]
then
  Puke "no command supplied"
fi

if [ -z "$hostlist" ]
then
  Puke "no host(s) supplied"
fi

case "$user_prefix" in
-*)
  Puke "no -u argument supplied" ;;
esac

if [ -n "$check_w_host" ]
then
  for h in $hostlist
  do
    if host 2>&1 >/dev/null
    then
      Puke "ypmatch cannot find '$h'"
    fi
  done
fi

if [ -n "$check_w_ypmatch" ]
then
  for h in $hostlist
  do
    if ypmatch hosts 2>&1 >/dev/null
    then
      Puke "ypmatch cannot find '$h'"
    fi
  done
fi


#--  OK, start doing useful things ---#
#

if [ -n "$input" ]
then
  # read input!
  $cat >$tmpfile
  # we can do away with the $tmpfile, with a fork for every host ...
fi

Rsh()
{
  case "$errtoout" in
    "") $rsh "$@" | $sed "s/^/$h: /" ;;
    *)  $rsh "$@" 2>&1 | $sed "s/^/$h: /" ;;
  esac
}

Rsh_w_tmp()
{
  if [ -f "$tmpfile" ]
  then
    $cat $tmpfile | Rsh "$@"
  else
    Rsh -n "$@"
  fi
}

for h in $hostlist
do
  if [ -z "$check_w_ping" ] || ping $h 2 >/dev/null  # note: "2 >"
  # host is active
  then
    #if [ -z "`$finger @$h 2>&1 | $grep 'Connection refused$'`" ]
    # host accepts finger - very crude check to see if rsh will work
    # however, finger has been disabled since, where I live
    if true
    then
      if [ -n "$verbose" ]
      then
        echo "executing '$command' on '$h'" 1>&2
      fi

      case "$bg" in
      "")
	      Rsh_w_tmp $user_prefix$h "$command" ;;
      *)
	      Rsh_w_tmp $user_prefix$h "$command" & ;;
	    esac
    fi
	fi
done

$rm -f $tmpfile