A command interpreter is a system software that recognizes and carries-out commands that are entered whilst communicating, by a human or from an alternative program. Command interpreters are a principal part of any operating system. It provides an interface linking/ connecting the user and the computer.
A command interpreter is frequently also called a command shell or clearly a shell.
A command shell also typically issues a set of programs or utilities which allows users to execute file management functions.
At present, most operating systems provide a GUI shell. Windows OS provides a GUI shell named explorer.exe and also provides another shell named cmd.exe to provide command line interface (CLI) support.
FireCMD is a merge of both CLI and GUI shells and hence it provides a new interface to users called GCLI (Graphical Command Line Interface).
FireCMD, like any other CLI shell, has a prompt. The prompt fetches that the command interpreter is ready to take a command from the user. The default prompt of FireCMD is “~> “.
A command is nothing but a set of instructions you want the command interpreter to perform.
Pressing the return key (Enter) executes the command. After a command is executed, a new prompt is provided for accepting the next command from the user.
Hello World Tutorial
Let’s do something with the FireCMD shell. Open FireCMD. Now without typing any text just press the Enter key, nothing happens? Well, unlike other shells FireCMD does not issue another prompt when the input is empty.
Let’s do something else. Type “abcd”, press enter and see what takes place. This time we get a message, which is:
“abcd” was not found!
This is an error message recommending that “abcd” doesn’t appear to be a permitted command. FireCMD was not able to find the command. You will also observe that the prompt returns to accept the next command.
This time we will enter a working command. Type “echohtml Hello World” without quotes and press Enter.
If everything is fine we will get an output. “Hello World” is written on the screen.
Here echohtml is a command name and “Hello World” is an argument supplied to it. echohtml is a command which prints the quarrel supplied on screen. echohtml supports a subset of HTML and CSS and you can use HTML tags to format the text. At this time, type “echohtml <b>Hello World</b>” and press enter. This time also “Hello World” gets printed on the screen but in a bold font.