How to Show Colored Text in Terminal?
There are many things that we see and use every day but rarely we stop and think “how does it work?”, other times we ask ourselves that question but dismiss it because we suppose that the answer is probably super complicated.
This was the case for me about wondering how terminals show different colors, in my mind, it has always been something extremely complicated until I realized it’s quite simple and easy.
For years I’ve been using tools that show colored output and from time to time I used them too, always relying on libraries such a chalk in Node.js
This until one day, I wanted to print some errors messages in red in a simple script and wanted to avoid using a library for such a simple case, that day I understand the basics of colors and another formatting in terminal output
all required is to print some special sequence of characters called ANSI escape and the text after that will have the specific color or background or text style
these are standardized and interpreted by almost any terminal emulator
for example the Espace code
\x1b[32m will start printing in green while
\x1b[0m is the reset Espace and will reset the next text to normal
try to print this in you terminal
echo "I'm normal \x1b[32m I will be green \x1b[47m I will have white background \x1b[4m I will be underscored \x1b[0m, not I'm back to normal"
How can I do it in my programming language?
as long the output is interpreted by an ANSI compatible terminal you only have to print the escape code, for example, the above command can be used as a string in
console.log("I'm normal \x1b[32m I will be gre en \x1b[47m I will have white background \x1b[4m I will be undescored \x1b[0m not I'm back to norm al")
These are some other cool escape codes you can try
Reset = "\x1b[0m" Bright = "\x1b[1m" Dim = "\x1b[2m" Underscore = "\x1b[4m" Blink = "\x1b[5m" Reverse = "\x1b[7m" Hidden = "\x1b[8m" FgBlack = "\x1b[30m" FgRed = "\x1b[31m" FgGreen = "\x1b[32m" FgYellow = "\x1b[33m" FgBlue = "\x1b[34m" FgMagenta = "\x1b[35m" FgCyan = "\x1b[36m" FgWhite = "\x1b[37m" BgBlack = "\x1b[40m" BgRed = "\x1b[41m" BgGreen = "\x1b[42m" BgYellow = "\x1b[43m" BgBlue = "\x1b[44m" BgMagenta = "\x1b[45m" BgCyan = "\x1b[46m" BgWhite = "\x1b[47m"
Some other cool colored and formatted text
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Blog by Jaga Santagostino.
Software consultant, polyglot developer, maker of things, lifelong learner.
ReactJS Milano & milano.dev organizer