FreeBSD has its Package and Ports software scheme. Both have dependency check and handle the automatic installation(s) when there is (are) any.
First of all, if you want to have a program but you do not have a clue of what is its name, try searching for it in popular FOSS sites such as Freecode (formerly known as freshmeat.net) etc. If you know the name and want to perform a search for it on the system you can do:
# whereis lsof
# echo /usr/ports/*/*lsof*
The latter will also include matches found in /usr/ports/distfiles/.
Generally, the ports directory structure is inside the /usr/ports directory.
You can also use the handy Ports Collection’s built-in search mechanism, by cd‘ing to the /usr/ports directory and executing:
# make search name=program(port)-name
The system search above is for the FreeBSD Ports facility. We will come back to it shortly.
Packages are convenient as they are pre-compiled versions of applications. As such, they have the primary advantage of not imposing the awareness and compilation setup work (as when any tweak is desired), but you have to accept a software that was compiled with a very simple configuration as it must be able to execute smoothly in many platforms. Another advantage (if you considered the latter as such ;)) is that the compressed archive is a lot smaller than the source code archive. You handle packages with simple commands such as pkg_add, pkg_info, pkg_version, pkg_delete etc.
Ports, on the other hand, are a set of files (Makefile, patch files etc.) that make the source code for applications to be ported to (able to compile in and, hence, function correctly in) the FreeBSD realm.
To have compiled software is more secure and you have the control of the application aspects, including the ability to turn features on or off during compilation. The port’s corresponding source code archive (known as the distfile) is larger than a correspondent (pre-compiled) package for the software, though. Nevertheless the many benefits it brings, like security, source code availability, and compiling for the architecture make it the best choice for a handful of people e.g. developers or folks that just appreciate one of the many advantages listed.
So, we will cover a bit of Ports usage. For more information on Package usage in FreeBSD go to its official handbook documentation.
In order to be able to use the Ports facility you must first get the Ports Collection:
# csup -L 2 -h cvsup.FreeBSD.org /usr/share/examples/cvsup/ports-supfile
Instead of the value for the -h option above, choose a mirror near you.
The handbook also shows the sequence of menu options needed to install it from the installation media but as it installs the old (as of the release) Ports Collection you should use the internet way as stated above and also on the handbook.
The Ports Collection is comprised of a set of Makefiles, patches and description files, divided up into port skeletons (one skeleton is a port) each of which is a minimal set of files containing instructions on how to build (compile) the source code, but does not include the actual source code.
With an Internet connection already setup, go to the port directory e.g. for lsof:
# cd /usr/ports/sysutils/lsof
and (also as root) execute make, make install, and then, as advised by the handbook, make clean (temporary files used during compilation). To run all of them with only one command you can just run make install clean – this will do all the work for you: download the distfile, uncompress, build and install it and then clean its temporary compilation files.
The following passage from the handbook (section on ports usage) is very important for those that do not have an Internet connection up all the time:
For users which cannot be connected all the time, the make fetch option is provided. Just run this command at the top level directory (/usr/ports) and the required files will be downloaded for you. This command will also work in the lower level categories, for example: /usr/ports/net. Note that if a port depends on libraries or other ports this will not fetch the distfiles of those ports too. Replace fetch with fetch-recursive if you want to fetch all the dependencies of a port too.
Note: You can build all the ports in a category or as a whole by running make in the top level directory, just like the aforementioned make fetch method. This is dangerous, however, as some ports cannot co-exist. In other cases, some ports can install two different files with the same filename.
For more activities on Ports, like changing the Default Ports Directories, Reconfiguring, Upgrading or Removing Installed Ports, consult the handbook section on ports usage.
The Ports Collection will use disk space over time. Always remember to make clean while inside the relevant directory, or simply portsclean -C (in any directory). To remove all the distfiles not referenced by any port, execute portsclean -D, or portsclean -DD to delete the ones not referenced by any port currently installed on your system. portsclean is a part of the portsupgrade suite (also explained by the handbook section on ports usage which makes numerous more tips not present in this article available!).
Welcome to FreeBSD!