Category Archives: Hacks

Simply logging JavaScript calls.

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When debugging complicated JavaScript one thing I find myself constantly doing is using console.log() to print out what functions are being called in what order. JavaScript is single-threaded and event driven so it’s often not entirely clear what functions will be called in what order.

Traditionally I’ve done something like this:

function foo(bar) {
  console.log('foo('+bar+')');
}

but last night I came up with something better. It’s probably not completely portable but it seems to work fine in recent Chrome / Safari / Firefox, which is really all I’m going to be using for debugging anyway:

function logCall() {
  console.log(logCall.caller.name + '(' +
    Array.prototype.slice.call(logCall.caller.arguments)
    .map(JSON.stringify).join(', ') +
    ')');
}

Just add logCall() to the start of functions and the function call (including serialized arguments) will be logged to the console. Easy and foolproof.

Showing git status in my Zsh prompt

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I like Zsh. It’s a powerful, efficient shell. It’s better than Bash by just about every metric (better performance, more features, better sh compatibility). I really have no idea why people keep using Bash.

Anyway, I put together a little piece of zshrc to show my current status in right-hand prompt – a prompt that’s shown right-aligned in the shell. Zsh has a couple of features that make this really easy.

First the prompt_subst options instructs the shell to do variable substitution when evaluating prompts. So if you were to set your prompt to '$PWD> ' then your prompt would contain your current directory. Of course you wouldn’t do it that way, %~ does that much more nicely, but that takes us to Zsh’s second feature, ridiculously powerful variable substitution and expansion. In my prompt I just use the simple $(shell-command) substitution, but there’s a full complement of file-io, string manipulation and more to be had.

setopt prompt_subst
autoload colors zsh/terminfo
colors

function __git_prompt {
  local DIRTY="%{$fg[yellow]%}"
  local CLEAN="%{$fg[green]%}"
  local UNMERGED="%{$fg[red]%}"
  local RESET="%{$terminfo[sgr0]%}"
  git rev-parse --git-dir >& /dev/null
  if [[ $? == 0 ]]
  then
    echo -n "["
    if [[ `git ls-files -u >& /dev/null` == '' ]]
    then
      git diff --quiet >& /dev/null
      if [[ $? == 1 ]]
      then
        echo -n $DIRTY
      else
        git diff --cached --quiet >& /dev/null
        if [[ $? == 1 ]]
        then
          echo -n $DIRTY
        else
          echo -n $CLEAN
        fi
      fi
    else
      echo -n $UNMERGED
    fi
    echo -n `git branch | grep '* ' | sed 's/..//'`
    echo -n $RESET
    echo -n "]"
  fi
}

export RPS1='$(__git_prompt)'
view raw git-prompt.zsh This Gist brought to you by GitHub.

Scripting Google Voice in Python

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In the interest of getting some of the fragments of code I’ve written off my hard disk and out where someone might find them useful I’ve decided to start dumping them into git repos with some very minimal documentation. Minimal enough that I actually kick them out there.

The first is a simple Python library to access Google Voice’s calling and texting functionality:

% python
Python 2.6.1 (r261:67515, Jun 24 2010, 21:47:49)
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from googlevoice import *
>>> gv = GoogleVoice('googleaccount', 'googlepassword')
>>> gv.sms('+1415MYNUMBER', 'this is a test')
>>> gv.call('+1415MYNUMBER', '18003569377')

The library depends on BeautifulSoup. It’s based on a bunch of work that I found on the internet. I don’t remember exactly whose techniques I ended up using, but there’s a bunch of example code out there, just not much that was simple to use and in Python.