crayon {crayon}

Colored terminal output

Description

With crayon it is easy to add color to terminal output, create styles for notes, warnings, errors; and combine styles.

Usage

## Simple styles
red(...)
bold(...)
# ...

## See more styling below

Arguments

...

Strings to style.

Details

ANSI color support is automatically detected and used. Crayon was largely inspired by chalk https://github.com/chalk/chalk.

Crayon defines several styles, that can be combined. Each style in the list has a corresponding function with the same name.

Genaral styles

• reset

• bold

• blurred (usually called ‘dim’, renamed to avoid name clash)

• italic (not widely supported)

• underline

• inverse

• hidden

• strikethrough (not widely supported)

Text colors

• black

• red

• green

• yellow

• blue

• magenta

• cyan

• white

• silver (usually called ‘gray’, renamed to avoid name clash)

Background colors

• bgBlack

• bgRed

• bgGreen

• bgYellow

• bgBlue

• bgMagenta

• bgCyan

• bgWhite

Styling

The styling functions take any number of character vectors as arguments, and they concatenate and style them:

  library(crayon)
  cat(blue("Hello", "world!\n"))

Crayon defines the %+% string concatenation operator, to make it easy to assemble stings with different styles.

  cat("... to highlight the " %+% red("search term") %+%
      " in a block of text\n")

Styles can be combined using the $ operator:

  cat(yellow$bgMagenta$bold('Hello world!\n'))

See also combine_styles().

Styles can also be nested, and then inner style takes precedence:

  cat(green(
    'I am a green line ' %+%
    blue$underline$bold('with a blue substring') %+%
    ' that becomes green again!\n'
  ))

It is easy to define your own themes:

  error <- red $ bold
  warn <- magenta $ underline
  note <- cyan
  cat(error("Error: subscript out of bounds!\n"))
  cat(warn("Warning: shorter argument was recycled.\n"))
  cat(note("Note: no such directory.\n"))

Author(s)

Maintainer: Gábor Csárdi [e-mail]

Other contributors:

• Brodie Gaslam [e-mail] [contributor]

• Posit Software, PBC [copyright holder, funder]

See Also

Useful links:

• https://r-lib.github.io/crayon/

• https://github.com/r-lib/crayon

• Report bugs at https://github.com/r-lib/crayon/issues

make_style() for using the 256 ANSI colors.

Examples

cat(blue("Hello", "world!"))

cat("... to highlight the " %+% red("search term") %+%
    " in a block of text")

cat(yellow$bgMagenta$bold('Hello world!'))

cat(green(
 'I am a green line ' %+%
 blue$underline$bold('with a blue substring') %+%
 ' that becomes green again!'
))

error <- red $ bold
warn <- magenta $ underline
note <- cyan
cat(error("Error: subscript out of bounds!\n"))
cat(warn("Warning: shorter argument was recycled.\n"))
cat(note("Note: no such directory.\n"))