You're using find in your current working directory. It seems you may need an introduction to find for Ubuntu (based on your other thread it seems you're using PostgreSQL 9.1 on Ubuntu):
This is probably a question for the authors of a book I have been reading but it may be faster to get an answer here.
I was trying to follow along in a book ‘Seven Databases in Seven Weeks’ and chapter 2 deals with PostgreSQL. One of the first things it does is issue a command ‘createdb book’. The text before this command says, “Once you have Postgres installed, create a schema called book using the following command: $ createdb book’ But when I tried to issue this command (at a Linux command prompt) I get ‘createdb command not found’. Are the authors out of date? What is the current command?
The authors are incorrect, in that this doesn't actually create a schema. It creates a database. but they are not out of tdate, just incorrect - it has never created a schema.
That said, the createdb command ships with postgresql still and should be avaiable. Exactly where it is depends on how you installed PostgreSQL, and which distribution of Linux you are on. You can probably find it with "find", or by looking at the contents of whichever package you used to install it.