This article assumes fun_plug is installed. It only explains what busybox is and how it works, so don’t expect to learn new useful Linux tricks.
Busybox calls itself “The Swiss Army Knife of Embedded Linux”. It is a single program that provides over 60 commonly used commands that are normally available on the Linux command line. Examples of such commands:
| ls | lists what’s in a directory |
| mkdir | creates directories |
| tar | creates/opens tarball files containing multiple files |
| cp | copies files |
In a standard Linux distribution these commands are separate programs. Busybox implements these programs (occasionally with somewhat reduced options) as a single executable program. Hence the “Swiss army knife” slogan. This saves space and maybe loading time, which is important for embedded Linux implementations.
To see what programs are handled by Busybox on the CH3SNAS you can use the following command within an ssh (PuTTY) session:
cd /bin ls -l | more
The piping via more allows you to view the folder listing produced ls at your own pace. Use the spacebar to see more of the listing, and q to quit the more utility. The output will contain dozens of lines like:
lrwxrwxrwx 1 root root 7 Apr 1 12:53 ln -> busybox lrwxrwxrwx 1 root root 7 Apr 1 12:53 ls -> busybox lrwxrwxrwx 1 root root 7 Apr 1 12:53 md5sum -> busybox lrwxrwxrwx 1 root root 7 Apr 1 12:53 mesg -> busybox lrwxrwxrwx 1 root root 7 Apr 1 12:53 mkdir -> busybox
Essentially this says that, for example, the file /bin/ls is a symbolic link (“->”) to the program /bin/busybox. You can get a feel for for this by trying
busybox ls -l /bin/busybox
yourself and seeing that it performs the same as typing ls -l /bin/busybox directly. Typing busybox without any parameters gives information like the program version and a list of all supported commands.