waitx

#!/bin/sh
help_base() { cat <</help
Wait until all given PIDs complete.
Usage: ${0##*/} [-w WAIT_TIME] PID [PID...]
  -F, --pidfile=FILE     Read the list of PIDs from the given FILE
  -h, --help             Display this helpful help
  -q, --query            Instead of PIDs, use \`pgrep\` patterns
  --query-help           Show the list of query options (\`-q\` or \`--query\`)
  -v, --verbose          Describe what we're waiting for
                         Verbose output is colorized unless \$NO_COLOR is set
  -w, --wait=WAIT_TIME   Polling interval (defaults to 5.0s)

/help
}
help() {
  help_base
  if [ -z "$LINES" ]; then LINES="$(tput lines)"; fi
  # if we're piped or query is enabled or it fits on one page, show query help
  if [ ! -t 1 ] || [ -n "$use_pgrep" ] \
  || [ "$LINES" -gt $(( $({ help_base; query_help; } |wc -l) + 3)) ]; then
    query_help
    echo
  fi
  version
}

version() {
  echo "Part of misc-scripts: https://github.com/adamhotep/misc-scripts"
  echo "waitx 2.1.20240806.0 copyright 2004+ by Adam Katz <@adamhotep>, GPLv3+"
  exit
}

query_help() { cat <</query_help
Query options (these all enable \`-q\` or \`--query\`)
  -f, --full             Query the full command line
  -g, --pgroup=PGROUP    Query only the given process group ID
  -G, --group=GROUP      Query only the given group ID
  -i, --ignore-case      Query without regard to case
  -n, --newest           Query only the most-recently-started match
  --ns=PID               Query just the namespace of PID
  --nslist=NAMESPACE     Query by namespace: ipc, mnt, net, pid, user, or uts
  -o, --oldest           Query only the least-recently-started match
  -O, --older=SECS       Query only PIDs older than SECS
  -P, --parent=PPID      Query only children processes of PPID
  -r, --runstates=STATE  Query only proccess of state(s) D,R,S,Z,...
  -s, --session=SID      Query only processes with the given session ID
  -t, --terminal=TERM    Query only processes controlled by TERM
  -u, --euid=EUID        Query only processes with this effective user ID
  -U, --uid=UID          Query only processes with this real user ID
  -x, --exact            Query only exact matches (with -f, full command)
/query_help
}

die() { printf '%s\n' "$@" >&2; exit 2; }
needs_arg() { if [ -z "$OPTARG" ]; then die "No arg for --$OPT option"; fi; }
# note: save_arg only works here because none of the arguments accept spaces
wait_time=5 pgrep_args= pidfile= use_pgrep= get_help=
save_arg() { pgrep_args="$pgrep_args $@"; }
while getopts fF:g:G:hinoO:P:qr:s:t:u:U:vVw:x:-: OPT; do
  if [ "$OPT" = - ]; then # long opt https://stackoverflow.com/a/28466267/519360
    OPT="${OPTARG%%=*}" OPTARG="${OPTARG#"$OPT"}" OPTARG="${OPTARG#=}"
  fi
  case $OPT in
    ( f | full )	save_arg "--full" ;;
    ( F | pidfile )	needs_arg; pidfile="$OPTARG" ;;
    ( g | pgroup )	needs_arg; save_arg "--pgroup $OPTARG" ;;
    ( G | group )	needs_arg; save_arg "--group $OPTARG" ;;
    ( h | help* )	get_help=1 ;;
    ( i | ignore-case )	save_arg "--ignore-case" ;;
    ( n | newest )	save_arg "--newest" ;;
    ( ns | namespace )	needs_arg; save_arg "--ns $OPTARG" ;;
    ( n*s*list )	needs_arg; save_arg "--nslist $OPTARG" ;;
    ( o | oldest )	save_arg "--oldest" ;;
    ( O | older )	needs_arg; save_arg "--older $OPTARG" ;;
    ( P | parent )	needs_arg; save_arg "--parent $OPTARG" ;;
    ( query*help* )	query_help; exit ;;
    ( q | query* )	use_pgrep=1 ;;
    ( r | runstate* )	needs_arg; save_arg "--runstates $OPTARG" ;;
    ( s | session* )	needs_arg; save_arg "--session $OPTARG" ;;
    ( t | term* )	needs_arg; save_arg "--terminal ${OPTARG#/dev/}" ;;
    ( u | euid )	needs_arg; save_arg "--euid $OPTARG";;
    ( U | uid ) 	needs_arg; save_arg "--uid $OPTARG";;
    ( v | verb* )	verbose=1 ;;
    ( V | ver* )	get_version=1 ;;
    ( w | wait | poll )	needs_arg; wait_time="$OPTARG" ;;
    ( x | exact )	save_arg "--exact" ;;
    ( ??* )		die "Illegal option --$OPT" ;;  # bad long option
    ( ? )		exit 2 ;;  # bad short option (error via getopts)
  esac
done
shift $((OPTIND-1))

if [ -n "$pgrep_args" ]; then
  use_pgrep=1
fi

if [ -n "$get_help" ]; then
  help
elif [ -n "$get_version" ]; then
  version
fi

if [ -n "$pidfile" ]; then
  # sooo much less work when we don't have to handle spaces!
  set -- "$@" $(cat "$pidfile")
elif [ -n "$pgrep_args$use_pgrep" ]; then
  # easier bc PIDs can't have spaces ... hopefully pgrep opts/args is the same
  set -- $(pgrep $pgrep_args "$@" |awk -v this=$$ '$1 != this')
fi

poll() {
  sleep "$wait_time"
}

# before implementing verbose, I used Linux procfs to limit `ps` calls
#if [ -d "/proc/$$" ]; then	# procfs (most Linux systems)
#  for pid in "$@"; do
#    while [ -d "/proc/$pid" ]; do poll; done
#  done
#else

newline='
'

pslist=
while true; do
  oldpslist="$pslist"
  pslist="$(ps -f "$@")"	# -f gives us PPID, which we need for no-args
  if [ $# = 0 ]; then		# no-args: other jobs in this shell session
    pslist="$(echo "$pslist" |awk -v PID=$$ -v PPID=$PPID -v this="${0##*/}" '
      NR == 1 {
        for (c = 1; c <= NF; c++) {
          if      ($c == "PID")  pid  = c
          else if ($c == "PPID") ppid = c
          else if ($c == "CMD")  cmd  = c
        }
      }
      $pid != PID && $pid != PPID && $ppid != PID # print unless waitx or parent
    ')"
  fi
  if [ "$pslist" = "${pslist#*$newline?}" ]; then
    break	# done!
  elif [ -n "$verbose" ] && [ "$pslist" != "$oldpslist" ]; then
    echo "${oldpslist:+$newline}Waiting for:"
    if [ -z "$NO_COLOR" ] && [ -n "$CLICOLOR_FORCE" -o -t 1 ]; then
      if command -v grcat >/dev/null; then	# use GRC for colors
        echo "$pslist" |grcat conf.ps
      else	# manually bold (code 1) and underline (code 4) the title row
        title="${pslist%%$newline*}"
        printf '\033[1;4m%s\033[m%s\n' "$title" "${pslist#$title}"
      fi
    else
      echo "$pslist"	# report changed list of what we're waiting for
    fi
  fi
  poll
done