1.5.0 • Public • Published


A command line utility, a bit like moreutils's ts, to prepend timestamp information to the standard output of another command. Useful for long-running processes where you'd like a historical record of what's taking so long.



Piping anything to gnomon will prepend a timestamp to each line, indicating how long that line was the last line in the buffer--that is, how long it took the next line to appear. By default, gnomon will display the seconds elapsed between each line, but that is configurable.

You can display total time elapsed since the process began: total

You can display an absolute timestamp: absolute

You can also use the --high and/or --medium options to specify a length threshold in seconds, over which gnomon will highlight the timestamp in red or yellow. And you can do a few other things, too.


If the realtime timestamp updating is distracting or incompatible with your terminal, it can be disabled:



--type=<elapsed-line|elapsed-total|absolute>        [default: elapsed-line]
-t <elapsed-line|elapsed-total|absolute>

  Type of timestamp to display.
    elapsed-line: Number of seconds that displayed line was the last line.
    elapsed-total: Number of seconds since the start of the process.
    absolute: An absolute timestamp in UTC.

--format="format"                                   [default: "H:i:s.u O"]
-f "format"

  Format the absolute timestamp, using PHP date format strings. If the type
  is elapsed-line or elapsed-total, this option is ignored.

--ignore-blank                                      [default: false]

  Do not prepend a timestamp to blank lines; just pass them through. When
  this option is active, blank lines will not trigger an update of elapsed
  time. Therefore, if a lot of blank lines appear, the prior timestamp will
  display the total time between that line and the next non-blank line
  (if the type is elapsed-time was selected).

--real-time=<number|false>                          [default: 500]
-r                                                  [non-tty default: false]

  Time increment to use when updating timestamp for the current line, in
  milliseconds. Pass `false` to this option to disable realtime entirely,
  if you need an extra performance boost or you find it distracting. When
  realtime is disabled, the log will always appear one line "behind" the
  original piped output, since it can't display the line until it's
  finished timing it.

-h seconds

  High threshold. If the elapsed time for a line is equal to or higher than
  this value in seconds, then the timestamp will be colored bright red.
  This works for all timestamp types, including elapsed-total and absolute,
  where the elapsed line time is not actually displayed.

-m seconds

  Medium threshold. Works just like the high threshold described above, but
  colors the timestamp bright yellow instead. Can be used in conjunction
  with a high threshold for three levels.


  • If a high and/or a medium threshold are specified, then all timestamps not meeting that threshold will be colored bright green.
  • If you pipe the output of gnomon into another command or a file (that is, not a tty) then the real-time option will be disabled by default and each line will appear only after it has been timed. You can force realtime by sending a --real-time=<ms> argument explicitly, but the ANSI codes would probably interfere with whatever you were trying to do. The sane default is to omit fancy stuff, like colors and escape sequences, when logging text directly to a file.


with npm do:

npm install -g gnomon


gnomon uses the MIT license.

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npm i gnomon

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