pengwynn/dotfiles — pull request #5 by nmeum (2013-03-11 20:51:06+00:00)
Title: Use zsh's $commands array

Instead of

```
if $(which program-name &> /dev/null)
echo "it is available"
fi
```

you should / can use zsh's $commands array

```
if (( $+commands[program-name] )); then
echo "it is available"
fi
```