#!/usr/bin/env bash

insert_date()
{
  while read
  do
    local date_value
    date_value="$(date +"%b %d %T %s.%N")"
    echo "${date_value} ${REPLY}"
  done
}

fatal_error_handler()
{
  local result="$?"
  local p_message="$1"
  local pid="${BASHPID}"
  (exit "${result}") ||
  {
    (
      cd "${BASH_SOURCE[1]%/*}"
      echo -n "${FUNCNAME[0]}: $(echo | insert_date)${PWD}/${BASH_SOURCE[1]##*/}:${BASH_LINENO[0]} ${FUNCNAME[1]}() PID(${pid})"
    )
    [ "${p_message}" != "" ] && echo -n " ${p_message}"
    echo
    return "${result}"
  } >&2
}

execute_with_retry()
{
  local p_max_try_count="$1"
  shift
  false
  local result="$?"
  local try_number=0
  while ((try_number < p_max_try_count))
  do
    echo "Execute command($@): try #$((try_number+1))/${p_max_try_count}" >&2
    "$@" && return
    result="$?"
    sleep 1
    ((++try_number))
  done
  return "${result}"
}

get_own_process_group()
{
  local ps_output
  ps_output=($(ps --no-heading -o pgrp "$$")) || fatal_error_handler || return
  [ "${#ps_output[@]}" = "1" ] || fatal_error_handler || return
  echo "${ps_output[0]}"
}