Updating Bash

A shell allows you to run commands to interact with your computer, it's the shells job to understand what you have written and to perform an action based on it. When you type "date" for example, the shell looks in all the locations it has stored for an executable called "date", runs it, and shows you the output.

There are various shells that work slightly differentially, but the one that comes default in OS X is Bash. By default OS X mavericks runs bash 3.2, we're going to update it to the latest version 4.2.

Prerequisites 

Before attempting this tutorial you'll need to have homebrew installed.

• Installing Homebrew 

This tutorial was done with the following versions:

• Mavericks (10.9)
• Homebrew (November 2013)

Installation

1. Open a terminal and install bash

brew install bash

Homebrew is pretty easy

Wait until bash has finished installing

Now the latest version of bash is installed, but you still have to configure some things to get your terminal to run the latest version at startup. We need to tell a configuration the location of new version of bash, and we need to run a command to actually change the shell.

Configuration

1. Use this one liner to add "/usr/local/bin/bash" to the end of this file "/etc/shells"

sudo bash -c "echo /usr/local/bin/bash >> /etc/shells"

A few extra steps are required when permissions are needed in directions.

2. Check the file with this command to confirm it was written correctly

cat /etc/shells

/usr/local/bin/bash

The command "chsh" which we'll use in a minute, won't allow you to pick a shell that isn't in this list.


3. Write the following into the terminal, followed by your password to change the default shell.

chsh -s /usr/local/bin/bash

chsh -s /usr/local/bin/bash

4. Close and reopen your terminal

5. Write the following commands in to check if the new shell is running

echo $SHELL

echo $BASH_VERSION

$SHELL and $BASH_VESRION are both environment variables.

End Notes 

Check out some other tutorials about OS X and the terminal.

• Click here to learn how to add color to your bash prompt (coming soon)
• Click here for a list of awesome command line utilities (coming soon)

Making "ls" command display color

In an effort to make a terminal in OS X behave more like a terminal would in linux this quick tutorial will make the command "ls" always display color when displaying directories content. This is helpful for quickly identifying what type of files we're dealing with, and generally just makes using the terminal more visually appearing.

Prerequisites

Before attempting this tutorial you'll need to have coreutils installed.

• Updating Coreutils (Homebrew)

This tutorial was done with the following versions:

• Mavericks (10.9) 
• GNU coreutils 8.21

Installation

1. Enter the following in a terminal

echo alias ls="'ls --color'" >> ~/.bash_profile

Note the double quotation marks. These are needed otherwise they're ignored by the echo command.

An easy 1-liner

The alias command tells the shell to run an alternative command in place of a string, in this case, it's running "ls --color" everything the string "ls" is entered. The echo command redirecting into the .bash_profile file just confirms that the shell runs this command every time it's started.

2. Restart the terminal

3. Perform the command to ensure it has worked.

ls

Glorious Color 

End Notes

Check out some other tutorials about diving into the terminal side of things in OS X.

• Click here on how to update your version of bash 
• Click here on how to add color to your bash prompt (coming soon)

Updating Coreutils (Homebrew)

Coreutils (GNU) are a set of basic utilities that most unix-like operating systems come with. Although OS X comes with most of them, some are very outdated and lack features we might want to use. One example of a feature we want is using the ls command (lists directory contents) to show colours based on the type of file.

Prerequisite

This tutorial is based on the assumption homebrew is installed

• Installing Homebrew

This tutorial will be used with homebrew but can be applied to other package managers (such as MacPorts) following the basic structure:

• Install Coreutils
• Change PATH environment variable to check coreutils directory first
• Restart terminal

This tutorial was done with the following versions:

• Homebrew (November 2013)
• Mavericks (10.9)

Installation

1. Open up your preferred terminal

2. Copy this into your terminal and press enter

brew install coreutils

coreutils installing

3. Run the following command 

gls --color

Pretty colors !

What you're doing here is running the "ls" command with the option --color. Because Homebrew doesn't want to be destructive to your system files and overwrite the ones that come with OSX, it sticks them in another folder and creates an alias of each command with the character "g" in front of it so you can access it.

If you're comfortable using the updated coreutils like this then you can stop this tutorial. If you're like me and wish to use them instead of writing "g" in front of the command every time, continue.

Configuration 

1. Run the following command

echo export PATH="/usr/local/opt/coreutils/libexec/gnubin:$PATH" >> ~/.bash_profile

2. now run another command

echo export MANPATH="/usr/local/opt/coreutils/libexec/gnuman:$MANPATH" >> ~/.bash_profile

Adding environment variable to your .bash_profile

What we've done here is basically told the shell to look in the directory of the updated utils before anything else. We've also told it to look in the man directory (for man pages) of the updated utils before anything else. For further explanation of the above command I encourage you to look into the following things.

• echo
• environment variables
• redirection 
• .bash_profile

3. Close and Open your terminal for the changes to take effect

4. Enter the following command

man ls  

5. Scroll to the bottom of the page (ctrl + g) and see that you're running an up-to-date version.

GNU Coreutils 8.21

End Notes

Check out some other tutorials about diving into the terminal side of things in OS X.

• Click here on how to add color to your ls command
• Click here on how to update your bash version