Unix Power Tools, 3rd Edition

Chapter 40. Software Installation

/usr/bin and Other Software Directories

The location for certain types of installed files is very important. For instance, on many Unix systems, binary files accessible by users are located in the subdirectory /usr/bin or /usr/local/bin . If the applications aren’t in these places, they may not be in the PATH environment variable and not easily accessible from the command line.

On my FreeBSD system, I’ve installed a utility called dos2unix , a file-formatting application that converts DOS newline character combinations to the Unix newline character. I used the FreeBSD Ports system to install the application, which automatically placed the program in my application directory, in my case /usr/local/bin. When I want to execute the application, I can run it from the command line without having to provide the location of the file:

dos2unix some.txt > new.txt

This command reformats the newline character of the contents of some.txt, converting DOS linebreaks to Unix ones.

The /usr/bin subdirectory differs from the /bin directory located directly off of the main root directory. The /bin directory has basic installed binaries built into the Unix operating system, with commands such as cd to change directory and so on. When you install an optional software application, it should not install software in the top-level binary subdirectory, but in /usr/bin, instead.

According to the Filesystem Hierarchy Standard (FHS), subdirectories (Linux- and BSD-specific) ...