In order to encode this information, a distinct sequence of characters is directly embedded into the text it receives. What is an ANSI Escape Sequence?ĪNSI escape sequences are a standard that allows a terminal to receive information, not only about font styles and colors, but also the cursor’s position and many other terminal options. That’s where ANSI escape sequences come in, as well as the tput command. Since the terminal only ever deals with text, programs that wish to specify the way a text should be printed must find a way to communicate the desired formatting in the text to be printed itself. All other colors come from either the shell or the programs that provide text to print. The shell indicates which font style and color, if any, should be used to display the command prompt. It inherits them by default from a theme, its own or the operating system’s. In truth, the terminal doesn’t decide what font style or color to display on its own. Being able to display a critical error message in red or to simply underline a link can be very useful. Plus, its users appreciate the option of displaying text in a different color or style.

In order to be able to print anything, the terminal needs a font and a color that contrasts with its background. A previous article explains the difference between a terminal, a console and a shell. While the command executes, the terminal might receive an output to print from whatever program is currently running. Typically, the shell provides a command prompt to print and as the user types a command, the terminal then prints each typed character. It prints whatever it receives from the standard input, the standard output or the standard error. Displaying the Styling Capabilities of a TerminalĪ terminal is an interface: its only function is to display text.

Ansi escape sequences rust