bash_multiprocess_with_complex_dependancies

depends.sh

#!/bin/bash
set -e
. <(base64 -d <<< X19fX19fXygpeyA6OyB9O18oKXsgOjsgfQ==)

_______ PREFLIGH UTILS _______________________________________________________________

NOW="$(date +%s)"
: ${STATES_DIR:=/tmp/spawn_states_$NOW}
mkdir -p "$STATES_DIR"
trap "rm -rf $STATES_DIR" EXIT

: ${DEBUG:="yep"}
debugp() { [[ $DEBUG == "yep" ]] && printf '[DBG:PID<%s>] %s\n' "$!" "$1"; }


_______ MAGIC _______________________________________________________________

# spawn_with_dependencies func <comma_separated_prereq_func> &
spawn_with_dependencies () {
  local _operation="$1"
  debugp "Spawned func $1 with $2 as dependancies"
  [[ -f "$STATES_DIR/$_operation" ]] && return 0
  [[ "$2" != "" ]] && {
    local _dependencies="$(sed 's/,/ /g' <<< "$2")"
    while :;do
      sleep 1
      for dependency in $_dependencies; do [[ ! -f "$STATES_DIR/$dependency" ]] && continue 2; done
      break
    done ; }
  $_operation
  touch $STATES_DIR/$_operation
}

_______ PROGAM _______________________________________________________________

a () { echo "a: i will sleep 2sec and have no dependancies"; sleep 2; }
b () { echo "b: i will sleep 5sec and depends on a and c"; sleep 5; }
c () { echo "c: i will sleep 1sec and depends on a"; sleep 1; }
d () { echo "d: i just echo lol and depends on a,b and c"; echo "  -> lol"; }
e () { echo "e: b,c and d were done before me" ; }

main () {
        spawn_with_dependencies e b,c,d &
        spawn_with_dependencies a &
        spawn_with_dependencies b a,c &
        spawn_with_dependencies c a &
        spawn_with_dependencies d a,b,c &
        wait -f
}

main