Clean up variable declarations.

memusg

#!/bin/bash
set -o errexit -o nounset -o pipefail
function -h {
cat <<USAGE
 USAGE: memusg COMMAND [ARGS]

  Measure memory usage of processes.

  This script is inspired by a script of the same name written by Jaeho Shin
  <netj@sparcs.org>.

  Only tested on OS X.
USAGE
}; function --help { -h ;}

function memusg {
  local pgid mem mems=()
  if [[ $# = 1 && $1 =~ ^[0-9]+$ ]]
  then pgid="$1"
  else bash -i -c '$@' "$1" "$@" & pgid="$!"
  fi
  while sleep 0.1
  do
    mem="$(psg "$pgid" -o rss= | xargs | tr ' ' + | bc)" || break
    mems=( "${mems[@]:+${mems[@]}}" "$mem" )
  done
  wait
  [[ ${#mems[@]} -le 0 ]] || percentiles "${mems[@]}" >&2
}

uname="$(uname)"
function psg {
  local pgid="$1" ; shift
  case "$uname" in
    Darwin|*BSD) ps -g "$pgid" "$@" ;;
    Linux)       ps   -"$pgid" "$@" ;;
    *)           err "Your OS is not supported." ;;
  esac
}

function percentiles {
  local unscaled i j data=()
  data=( $(printf '%s\n' "$@" | sort -n ) )
  printf '%s\t%s\n' %-tile K-mem
  for percentile in 100 99 95 90 50
  do
    unscaled=$(( $percentile * ($# - 1) ))
    i=$((  $unscaled       / 100 ))
    j=$(( ($unscaled + 99) / 100 ))
    i="${data[$i]}"
    j="${data[$j]}"
    printf '%d\t%d\n' "$percentile" $(( ($i + $j) / 2 ))
  done
}

function msg { out "$*" >&2 ;}
function err { local x=$? ; msg "$*" ; return $(( $x == 0 ? 1 : $x )) ;}
function out { printf '%s\n' "$*" ;}

if [[ ${1:-} ]] && declare -F | cut -d' ' -f3 | fgrep -qx -- "${1:-}"
then "$@"
else memusg "$@"
fi