#!/usr/bin/env bash

#
# scatter(1) -- Run a command on every hostname returned by shoal(1) and print
# both stdout and stderr, including allocating a pty with -t.
#
# Author: Tom Ryder <tom@sanctum.geek.nz>
# Copyright: 2014
# License: Public domain
#

# Name self
self=scatter

# Handle ^C interrupts
trap 'trap - INT; kill -INT $$' INT

# Bail if we couldn't find shoal(1)
hash shoal || exit

# Exit with usage method if no arguments given
if ! (($#)) ; then
    printf 'USAGE: %s <command>\n' "$self" >&2
    exit 1
fi

# Execute command, print both stdout and stderr, and use file descriptor 3 to
# avoid clobbering any of the standard streams
while read -r hostname <&3 ; do
    printf '%s: %s\n' "$self" "$hostname"
    # shellcheck disable=SC2029
    ssh -qt -- "$hostname" "$@"
    printf '\n'
done 3< <(shoal)