Saturday, December 13, 2008

MacPorts, Up and Running

MacPorts is a system designed to let you easily install and manage free, open source software on OS X. Until late in 2006, the project was named DarwinPorts. There are disk image downloads available for 10.3 (Panther), 10.4 (Tiger), and 10.5 (Leopard). If you have a different version, you can download the source code and compile it.

updated for MacPorts 1.6 and Leopard on January 16, 2008

The Ports concept

If you are new the "ports" concept, the way the system works may be hard to grasp. The ports system was developed in the BSD community as a way to easily install and manage software on any BSD system. It was designed to automate the manual process programmers followed to port software from one Unix-like system to another. Most of the software in the ports repository is written in the C language and requires a C compiler.

When a particular package is requested, the ports system checks the version of the system it is running on, the version of the available source code, then downloads the source, applies any patches needed for it run on the local system, compiles it, and installs it. The design of the ports system only requires package maintainers to write scripts that handle any differences in the local system (like library versions, hardware architecture, compiler versions, etc.). The heavy lifting is done by the ports system itself.

This system is ingenious and works well in most situations, but you may occasionally run into a package that doesn't work. If that happens, it is usually because the source program was recently updated and the port scripts haven't caught up.

Universal ports

An Apple enhancement to the original ports system allows some software to be built (compiled) as universal binaries. This option may be desirable if you share binaries between Intel and PPC Macs, or plan to upgrade soon and don't want to install your ports again.

Installing MacPorts

According to the MacPorts wiki, there are three critical steps that must be done prior to installing MacPorts:

  1. Install Xcode Tools
  2. Install XWindows (X11)
  3. Set the shell environment

Both Xcode Tools (which includes the compiler), and X11 are available on the Mac DVDs. They can also be downloaded from the Apple developer web site. I had already installed Xcode and XWindows, so the only thing I needed to do was modify my $HOME/.bash_login file to include the /opt/local directories in my PATH and set the DISPLAY variable with "export DISPLAY=:0.0". See the wiki page for additional details.

After setting my shell environment, I downloaded version 1.6 of the MacPorts disk image for 10.5 (Leopard) from the download area. I mounted the disk image and ran the .pkg installer to install MacPorts. It completed with no errors.

If you want to tweak the port system configuration, the default location of the global config file is /opt/local/etc/macports/macports.conf.

Getting started

Once the ports system was installed, I followed the wiki recommendation and updated MacPorts itself with this Terminal command:

sudo port -d selfupdate

Next, I installed a simple program to see what kind of output the system produced. Here is the output from installing dos2unix, a program that changes the line endings of a text file from DOS to UNIX format.

sudo port install dos2unix
---> Fetching dos2unix
---> Attempting to fetch dos2unix-3.1.tar.gz from
---> Verifying checksum(s) for dos2unix
---> Extracting dos2unix
---> Configuring dos2unix
---> Building dos2unix with target all
---> Staging dos2unix into destroot
---> Installing dos2unix 3.1_0
---> Activating dos2unix 3.1_0
---> Cleaning dos2unix

When the port command finished, I had a freshly compiled dos2unix program sitting in /opt/local/bin/. Everything is nicely isolated in /opt/local/ to prevent any port program from interfering with the original Apple system.

One of more powerful features of ports is that it understands program dependencies. If you ask it to install a program that requires other programs or libraries to run, the ports system first installs the required components, then completes your request. For example, I wanted to install wget, a useful command line tool to download files or mirror web sites. I started the install with:

sudo port install wget

After starting it, I walked away. When I came back 30 minutes later, ports was still still installing dependencies. There were five dependencies that got installed first:


If you start a port install and your system seems sluggish, check to see if ports is still downloading and compiling dependencies.

Uninstalling MacPorts

Because of the way MacPorts files are isolated, it can be easily removed. To uninstall both the MacPorts system and all ports installed, the wiki lists the following files and directories to delete:


To my surprise, my installation did not include these files and directories:


Since the system appears to be fully functional, it is possible that this part of the wiki is slightly out of date.

Update January 10, 2008: Seth Milliken wrote in and noted that these directories are only created if you install a port that uses them, e.g. installing a Cocoa app will create /Applications/MacPorts/.

Common port commands

Here are some commands you may find useful while learning to use the ports system.

Command Result
port install package installs a package
port uninstall package uninstalls a package
port installed shows all ports currently installed
port uninstalled shows all ports not currently installed, you may want to pipe the output of this command to grep to limit the output
port search regex search for a port whose name matches the regex
port info package shows meta information on a package
port list shows the latest version of all available ports

See the port man page for additional options.

Filling in the holes

MacPorts can sometimes provide a software solution the default Apple software does not. For me, that usually means a command line or system oriented tool, but there are plenty of GUI applications available, too. The MacPorts team has done a nice job "porting" the ports system to the Mac. It is one of the most popular features of BSD, and one of the reasons I am running a Mac today.