1 If your wooden pallets contain low-grade engineered wood or cardboard, they may also contain formaldehyde and harbor all kinds of critters you don't want to know about.
Command shell overview. The command shell is a separate software program that provides direct communication between the user and the operating system. The non-graphical command shell user interface provides the environment in which you run character-based applications and utilities.
In Unix, the shell is a program that interprets commands and acts as an intermediary between the user and the inner workings of the operating system.o Unix, the shell is just another program. For this reason, any program can be designated a login shell in /etc/shells. For example, some Emacs users pride themselves on never needing a traditional shell prompt.