Mac OS X Leopard - ARCAism

### aliases ###
alias ls="ls -FG"
alias la="ls -FGA"
alias ll="ls -FGAl"
### functions ###
function pman() {
man -t "${1}" | open -f -a /Applications/Preview.app/
}
Again, the lines that begin with # are comments.
Creating Commands with Aliases and Functions
The preceding sample .bashrc file shows a few aliases and a function. Essentially, these are both
ways to create simple command-line commands that carry out more complex commands. In general,
an alias is a way of creating a shortened version of a single command, while a function
creates a command out of an actual shell script that may consist of many commands and simple
logic.
Aliases are incredibly handy when you find you are using the same commands over and over
and want to simplify them; you can even use them to essentially overwrite the default behavior
of a command. Take the first alias listed previously:
alias ls="ls -FG"
This command creates the ls alias from the ls -FG command, effectively overwriting ls so
that it will, by default, provide colored output and the benefits of the -F flag as well. The other
two aliases in my .bashrc file also create aliases to other common ls options.
NOTE You can create aliases at the command line using the alias command as well—
however, if you don’t save these to your .bashrc file, they will be gone once you exit that
particular shell.
Functions, on the other hand, are more complex, as they are essentially simple shell scripts.
Here’s an example from the preceding .bashrc file:
function pman() {
man -t "${1}" | open -f -a /Applications/Preview.app/
}
The first line defines pman as a function accessible from the command line, and everything
between the curly braces defines what happens when we use the pman command. So, if I were to
enter pman ls at the command line, the function would take the first argument, ls, and run
man -t ls | open -f -a /Applications/Preview.app/, thus allowing me to simply open the man
page of any command in the Preview application in one simple command.
Summary
CHAPTER 18 INTRODUCING DARWIN AND THE SHELL 327
Whew, there was lots of info in this chapter. While the aim wasn’t to teach you everything about
working with Darwin (which would be an entire book in itself just to scratch the surface), hopefully
you now know enough to get around comfortably in Darwin, and more importantly, have