Question

Medal+Testimonial

In Unix-based operating systems What is the purpose of the bin directory?

Answer 1

It stands for "binaries" and contains certain fundamental utilities, such as ls or cp, that are needed to mount /usr, when that's a separate filesystem, or to run in single-user (administrative) mode when /usr cannot be mounted.

Answer 2

Unix was written in the very early 1970's. At that time, hard drives were only a few megabytes in size. Many HDs were needed to make a file system. The root file system, /, is both the starting point for absolute paths and was usually on one HD. The root filesystem was pretty much guaranteed to mount on boot. /bin has the binaries that are fundamental for running a computer.

The usr partition is usually the next filesystem to mount on the /usr directory of the root drive. It has Unix for the users, hence the duplication between the root and usr partitions. /usr/bin has the user type binaries.

Some *nixes have a /usr/local directory for the local stuff. /usr/local/bin is for locally installed binaries. Some *nixes put this in the /opt partition because it's optional stuff.

The sbin directories, when they exis,t are for System BINaries. Programs to assemble the filesystems, daemons, ubergeeky stuff.

Answer 3

As other have stated, bin is short for binary. I would add that computers run binary code. That is why it was chosen. It means it is something that can be run, as opposed to say a log directory that usually holds text based logs. Programmers tend to use simple, logical names for things. They have done so for a long time. So in many forms of DOS, dir is a command to get the \(\textbf{dir}\)ectory listing, where UNIX chose the ls of \(\textbf{l}\)i\(\textbf{s}\)ting. All these things may look a bit cryptic, but they tend to be one short for or another of what they relate to.

Oh, and some of the original file systems had an eight character limit on a lot of things, which is why they had to be so short. That, plus a desire not to type out long commands like "directory listing" every time is why they went with the really short stuff. Use of bin for a directly you would type a lot of times to save over typing binary is why things are less than 8 a lot of times.