Need menu bar app to show output of Terminal command every 60s

I need a menu-bar app* which will show me the output of a terminal command, and run that Terminal command every 60s or so.

Or I need a menu-bar app which will read the contents of a file, and update whenever that file is updated.

(The output would be no more than 3 or 4 digits)

Are there any such apps?

* neither the Dock nor the Desktop are workable alternatives. Needs to be the menu bar.

Update 2014-06-16: The answer from Jun 9 '12 at 2:15 did not end up working for me after all, so I'm still looking for a solution.

2020-04-04

I forgot all about having asked this question. For the past several years I have been using TextBar which is the perfect solution that I had always been looking for.

See also:

TextBar Puts Your Text into the Menu Bar - MacStories

#!/usr/bin/env ruby

require "osx/cocoa"
include OSX

app = NSApplication.sharedApplication 
statusitem = NSStatusBar.systemStatusBar().statusItemWithLength(NSVariableStatusItemLength)
while true
    statusitem.setTitle(rand(999))
    sleep 1
end
app.run

(If anyone who actually knows Cocoa wants to improve this, feel free to edit.) I more or less just copied the script from taw's blog: Personal experience points and OSX menulets, which was mentioned in display - Is there a way to have AppleScript output displayed in the menubar? - Apple.

Here is the solution in python.
Install rumps framework (linked repository has patch for OS X 10.9.3)
sudo pip install git+https://github.com/tito/rumps

You might need to adjust $PYTHONPATH to include pyobjc (Foundation)
export PYTHONPATH=/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python

Adjust the following code for your needs:

#!/usr/bin/env python
import rumps
import os
import threading


class AwesomeStatusBarApp(rumps.App):
    def __init__(self):
        super(AwesomeStatusBarApp, self).__init__("Awesome App", "Title")
        tail(self)


def tail(self):
    threading.Timer(5, tail, [self, ]).start()
    self.title = os.popen("tail -1 /var/log/system.log").read()[0:-1][0:50]

AwesomeStatusBarApp().run()

Do not forget to limit the length of the string ([0:50]) (or OS X will remove it in favor of menus if they both don't fit), and get rid of the newline in the end ([0:-1])

There is another recent open source alternative called BitBar (MIT License), which appears very similar to "TextBar" and "ShellWrangler" and amazes through its simplicity.

You can execute scripts at any time interval that is encoded in the script file name (e.g. my_script.60s.py) and it can execute any script you can also execute in your Terminal.

I was searching for such tool many times until I have implemented that for my self: http://shellwrangler.com. No ads, it’s free and you can build anything you like.