Color Terminal

color-terminal is a small package that can be used with node.js to control terminal output. The package can move the cursor in the terminal and output colored text. It can colorize a message with a simple straightforward markup syntax.

Installation and use

Install with npm to current directory:

  npm -d install color-terminal .

Or install globally:

  npm -d -g install color-terminal

Then require() package from your script:

  terminal = require('color-terminal')

Examples

Some examples from the examples directory.

Features

Colors

Control colored output. See also examples/colors.js. Colors may vary depending on the terminal settings.

Simple color changing:

  terminal.color('magenta').write('Unicorn');

This will output Unicorn in magenta (or purple). To change the background color to magenta:

  terminal.color('magenta', 'background').write('Unicorn');

Color formatting

color-terminal supports formatting strings with colors using a simple syntax. Outputting Unicorn in magenta (like the example above) would look like this:

  terminal.colorize('%mUnicorn');
  
  # And changing the background color to magenta 
  terminal.colorize('%5Unicorn');

Using this syntax we can create Rainbows easily in one line:

  terminal.colorize('%rR%ma%ci%bn%yb%go%rw%n\n');
  
  # Or with background colors 
  terminal.colorize('%w%1  R  %2  A  %3  I  %4  N  %5  B  %6  O  %7  W  %n ');

The colorize function accepts the following modifiers:

                  text      text            background
      ------------------------------------------------
      %k %K %0    black     dark grey       black
      %r %R %1    red       bold red        red
      %g %G %2    green     bold green      green
      %y %Y %3    yellow    bold yellow     yellow
      %b %B %4    blue      bold blue       blue
      %m %M %5    magenta   bold magenta    magenta
      %p %P       magenta (think: purple)
      %c %C %6    cyan      bold cyan       cyan
      %w %W %7    white     bold white      white

      %F     Blinking, Flashing
      %U     Underline
      %8     Reverse
      %_,%9  Bold

      %n,%N  Resets the color
      %%     A single %

Multiple effects also can be set by providing Object as parameter to color() method:

  terminal.color({"attribute": "bold", "foreground": "yellow"}).write('Yellow bold text')

Colored ouput can be reset with the reset() function:

  terminal.color('red').write('This is red,').reset().write(' and this is not')

Notice about color modifiers and colorize()

Remember, that multiple modifiers does not requires to reset formatting before EOL. Example:

  # 'Rainbow', thin colors. 
  terminal.colorize('%rR%ma%ci%bn%yb%go%rw%n\n') # => 'Rainbow' in different colors 
  
  # 'Rainbow', thin colors, bold modifier. 
  terminal.colorize('$_%rR%ma%ci%bn%yb%go%rw%n\n') # => Bold 'Rainbow' in different colors 
  
  # 'Rainbow', bold colors. 
  terminal.colorize('%RR%Ma%Ci%Bn%Yb%Go%Rw%n\n') # => The same. 

So, as you see, you don't need to output reset modifiers every time you colored text. Better practice will be use of reset() method called next to colorize():

  # Best practice 
  terminal.colorize('%RR%Ma%Ci%Bn%Yb%Go%Rw').reset()

String#color()

You can use color formatting with String color() method. Example:

  # String#color() accepts three parameters: foreground(text) color, background color and style attribute. 
  "string".color('white', 'red', 'blink') # => Blinking white string 'string' with red background 
  
  # If you need just to set foreground color and style and not the background, pass null or empty string to param: 
  "another string".color('blue', null, 'bold') # => Is equivalent to: 
  "another string".color('blue', '', 'bold')

Cursor control

color-terminal provides methods for terminal cursor positioning. It can be usable in situations when you need strict text formatting. Example:

  # 'move()' function uses left top corner as (0,0) origin, so (5,7) coords means that resulting point 
  # will be placed 5 symbols from the top corner and 7 symbols from the left corner. 
  # 
  # To reset terminal, you can use 'reset()' and 'clear()' methods. 
  terminal.move(5, 7).color('red').write('*').reset().clear() 

color-terminal also contains shorthand methods for cursor positioning that help to avoid geometric mess with 'move()' method:

  # Places cursor 10 symbols up from the bottom corner. 
  terminal.up(10).write('yay!')
  
  # Places cursor 2 symbols down from the current position. 
  terminal.down(2).write('down')
  
  # Places cursor 4 symbols right from the current position. 
  terminal.right(2).write('padding')
  
  # Places cursor 6 symbols left from the current position. 
  terminal.left(6).write('left-left')

'Cleaners'

Useful methods to clear contents from terminal.

  # Clear all characters from the terminal 
  terminal.clear()
  
  # Clear the line the cursor is at 
  terminal.clearLine()
  
  # Clear the next `n` characters from the current cursor position. In current example method will clear six characters. 
  terminal.clearCharacters(6) # => equals terminal.write(new Array(6 + 2).join(' ')).left(6 + 2) 

Other methods

  # Write the `n` new lines. 
  terminal.nl(2)  # => "\n\n" 
  
  # Write the `n` tabulation characters. 
  terminal.tab(4) # => "\t\t\t\t" 

Credits

Original package by Mattijs Hoitink.

• mattijs@GitHub — GitHub profile.
• mattijs/node-terminal — original package.
• monkeyandmachine — author's blog.

This fork of the package maintained and developed by Forgotten Labors Initiative.

License

color-terminal is licensed under the MIT License.