Colored terminal output on terminals that support 'ANSI' color and highlight codes. It also works in 'Emacs' 'ESS'. 'ANSI' color support is automatically detected. Colors and highlighting can be combined and nested. New styles can also be created easily. This package was inspired by the 'chalk' 'JavaScript' project.
With crayon it is easy to add color to terminal output, create styles for notes, warnings, errors; and combine styles.
ANSI color support is automatically detected and used. Crayon was largely inspired by chalk.
devtools::install_github("r-lib/crayon")library(crayon)
Crayon defines several styles, that can be combined. Each style in the list has a corresponding function with the same name.
reset
bold
blurred
(usually called dim
, renamed to avoid name clash)italic
(not widely supported)underline
inverse
hidden
strikethrough
(not widely supported)black
red
green
yellow
blue
magenta
cyan
white
silver
(usually called gray
, renamed to avoid name clash)bgBlack
bgRed
bgGreen
bgYellow
bgBlue
bgMagenta
bgCyan
bgWhite
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'))
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 $ boldwarn <- magenta $ underlinenote <- cyancat(error("Error: subscript out of bounds!\n"))cat(warn("Warning: shorter argument was recycled.\n"))cat(note("Note: no such directory.\n"))
Most modern terminals support the ANSI standard for 256 colors,
and you can define new styles that make use of them. The make_style
function defines a new style. It can handle R's built in color names
(see the output of colors()
), and also RGB specifications, via the
rgb()
function. It automatically chooses the ANSI colors that
are closest to the specified R and RGB colors, and it also has
a fallback to terminals with 8 ANSI colors only.
ivory <- make_style("ivory")bgMaroon <- make_style("maroon", bg = TRUE)fancy <- combine_styles(ivory, bgMaroon)cat(fancy("This will have some fancy colors"), "\n")
MIT @ Gábor Csárdi
Style fucntions convert arguments to character now
Autodetect RStudio ANSI support
col_align()
gains type
argument, default "width"
(#54).
Removed dependency to memoise
(@brodieG, #25)
Fixed a test case that changed the crayon.enabled
setting, potentially (@brodieG)
Added crayon.colors
option, to specify the number of
colors explicitly
TERM=xterm
and tput colors=8
will use 256 colors,
as 256 colors are usually supported in this case (#17)
Support colors in ConEmu and cmder, on Windows
Fix color detection in Emacs tramp
col_strsplit
and col_substr
corner cases:
handle empty chunks at beginning or end of strings
like base::strsplit
(@brodieG, #26)
explicitly deal with 'split' values that are not length 1 as that is not currently supported
handle zero length x
argument in col_substr
, and
add more explicit error messages for corner cases
Some performance improvements to col_substr
(@brodieG)
Change rgb to ANSI code mapping, based on the "paint" ruby gem (@richfitz, #33, #34)
R CMD check
problems.Colors are turned on by default in Emacs ESS 23.x and above.
Functions to turn on and off a style: start
, finish
.
Really fix tput
corner cases (@jimhester, #21)
tput
exists, but
fails with an error and/or does not return anything useful.
(@jimhester, #18, #19)Fix detection of number of colors, it was cached from installation time (#17).
Color aware string operations. They are slow and experimental currently.
show_ansi_colors()
prints all supported colors on the screen.
256 colors, on terminals that support it.
Disable colors on Windows, they are not supported in the default setup.