Raspberry Pi_Eng_08.2.2 Specifying Default Shell Program

Posted on by realomega

8.2.2 Specifying Default Shell Program

There are various Shell programs available in Linux, and other Shell programs may be provided depending on the distribution. If you have other Shell programs you need, you can also use the Shell program.

On Linux, information about the Shell program currently installed on the system is stored in the “/etc/shells” file. If you check the information just like below, you can see that you can use various Shell programs. One of these several Shell programs installed in the system is specified as the Shell program used by default in the system.

Raspberry Pi_Eng_08.2.1 Shell and BASH (Bourne Again Shell)

Posted on by realomega

8.2 Shell Program

8.2.1 Shell and BASH (Bourne Again Shell)

When we execute a command in the Terminal program, the Shell program accepts and interprets the command internally, instructs the system kernel to process it, and when processing is complete, it receives the result from the kernel and returns it to the Terminal program. Since the Shell is between the Terminal and system kernels, and handles all requests that the Terminal program requires, the Terminal program does not need to know anything about the system kernel. It is called a Shell in the sense that it serves to provide the necessary services to external Terminals that needs to receive services from the kernel while enclosing the system kernel as if the clamShell surrounds the contents.