lapdu - Lap for du.

lapdu.sh

#!/usr/bin/env bash
#
# Lap for du.
# Copyright (c) 2018 Koichi OKADA. All rights reserved.
# This script is destributed under the MIT license.
#

source hhs.bash 0.2.0

function init_lapdu ()
{
  : ${OPT_INTERVAL:=5}
  : ${OPT_SCALE:=1000000}
  : ${OPT_UNIT:=MB}
  : ${OPT_WIDTH:=5.1}
}

function optparse_lapdu ()
{
  case "$1" in
  -i|--interval) # <interval>
    # Set lap intervals for du in seconds.
    # Default is 5 seconds.
    nparams 1
    optset INTERVAL "$2"
    ;;
  -u|--unit) # <unit>
    # Set unit for byte size.
    # <unit> can take /([kMGT]|Ki|Mi|Gi|Ti)B?|B/.
    # Default is MB.
    nparams 1
    case "${2,,}" in
    b)      optset UNIT B   ; optset SCALE 1 ;;
    k|kb)   optset UNIT kB  ; optset SCALE $(( 1000 ** 1 )) ;;
    m|mb)   optset UNIT MB  ; optset SCALE $(( 1000 ** 2 )) ;;
    g|gb)   optset UNIT GB  ; optset SCALE $(( 1000 ** 3 )) ;;
    t|tb)   optset UNIT TB  ; optset SCALE $(( 1000 ** 4 )) ;;
    ki|kib) optset UNIT KiB ; optset SCALE $(( 1024 ** 1 )) ;;
    mi|mib) optset UNIT MiB ; optset SCALE $(( 1024 ** 2 )) ;;
    gi|gib) optset UNIT GiB ; optset SCALE $(( 1024 ** 3 )) ;;
    ti|tib) optset UNIT TiB ; optset SCALE $(( 1024 ** 4 )) ;;
    *)
      error "Unknown unit for byte size: $2"
      eixt 1
      ;;
    esac
    ;;
  -w|--width) # <width>
    # Set width and precision for template of printf.
    # Default is `5.1`.
    nparams 1
    optset WIDTH "$2"
    if ! [[ "$2" =~ ^[0-9]+\.[0-9]+$ ]]; then
      error "Invalidh format of width: $2"
      exit 1
    fi
    ;;
  *) return 1 ;;
  esac
}

function lapdu () # [<options>] [<params> ...]
#   Lap for du.
# Params:
#   Params will be passed to `du`.
#   Note, however, that options for `du` must be placed after `--`.
{
  local i
  while true; do
    (( 1 < i++ )) && sleep "${OPT_INTERVAL:-5}";
    du -bc "$@" \
    | tail -n1
  done \
  | awk -vscale="$OPT_SCALE" -vunit="$OPT_UNIT" -vwidth="${OPT_WIDTH%%.*}" -vprecision="${OPT_WIDTH##*.}" \
    '
      function getstamp(_t){
        cmd = "date +%s.%N";
        cmd | getline _t; close(cmd);
        return 0+_t;
      }
      {
        t2 = t1; t1 = getstamp();
        n2 = n1; n1 = $1;
      }
      0 < t2 {
        delta = (n1-n2) / scale;
        printf("%'\''*.*f %s (%'\''*.*f %s/s)\n", width, precision, delta, unit, width, precision, delta / (t1-t2), unit);
      }
    '
}

invoke_command "$@"