How can I use Ruby to colorize the text output to a terminal

Question

Using Ruby  how can I perform background and foreground text colorization for output in the terminal  I remember  when programming Pascal we all used to write our own textcolor      procedures to make our small educational programs look more pretty and presentational  How would I go about coding an equivalent of that in Ruby   Is there any built-in support in the core library that lends itself to this   If not  what would be an idiomatic way to add it

User · Answer

I found the answers above to be useful however didn't fit the bill if I wanted to colorize something like log output without using any third party libraries. The following solved the issue for me:

red = 31
green = 32
blue = 34

def color (color=blue)
  printf "\033[#{color}m";
  yield
  printf "\033[0m"
end

color { puts "this is blue" }
color(red) { logger.info "and this is red" }

I hope it helps!

User · Answer

You can use ANSI escape sequences to do this on the console  I know this works on Linux and OSX  I m not sure if the Windows console  cmd  supports ANSI   I did it in Java  but the ideas are the same     foreground color public static final String BLACK TEXT       return   033 30m    public static final String RED TEXT         return   033 31m    public static final String GREEN TEXT       return   033 32m    public static final String BROWN TEXT       return   033 33m    public static final String BLUE TEXT        return   033 34m    public static final String MAGENTA TEXT     return   033 35m    public static final String CYAN TEXT        return   033 36m    public static final String GRAY TEXT        return   033 37m       background color public static final String BLACK BACK       return   033 40m    public static final String RED BACK         return   033 41m    public static final String GREEN BACK       return   033 42m    public static final String BROWN BACK       return   033 43m    public static final String BLUE BACK        return   033 44m    public static final String MAGENTA BACK     return   033 45m    public static final String CYAN BACK        return   033 46m    public static final String WHITE BACK       return   033 47m       ANSI control chars public static final String RESET COLORS     return   033 0m    public static final String BOLD ON          return   033 1m    public static final String BLINK ON         return   033 5m    public static final String REVERSE ON       return   033 7m    public static final String BOLD OFF         return   033 22m    public static final String BLINK OFF        return   033 25m    public static final String REVERSE OFF      return   033 27m

User · Answer

As String class methods  unix only    class String def black             e 30m  self  e 0m  end def red               e 31m  self  e 0m  end def green             e 32m  self  e 0m  end def brown             e 33m  self  e 0m  end def blue              e 34m  self  e 0m  end def magenta           e 35m  self  e 0m  end def cyan              e 36m  self  e 0m  end def gray              e 37m  self  e 0m  end  def bg black          e 40m  self  e 0m  end def bg red            e 41m  self  e 0m  end def bg green          e 42m  self  e 0m  end def bg brown          e 43m  self  e 0m  end def bg blue           e 44m  self  e 0m  end def bg magenta        e 45m  self  e 0m  end def bg cyan           e 46m  self  e 0m  end def bg gray           e 47m  self  e 0m  end  def bold              e 1m  self  e 22m  end def italic            e 3m  self  e 23m  end def underline         e 4m  self  e 24m  end def blink             e 5m  self  e 25m  end def reverse color     e 7m  self  e 27m  end end   and usage   puts  I m back green  bg green puts  I m red and back cyan  red bg cyan puts  I m bold and green and backround red  bold green bg red   on my console     additional   def no colors   self gsub   e   d m      end   removes formatting characters  Note  puts   e 31m    set format  red foreground  puts   e 0m      clear format puts  green-   red  red -green  green   will be green-red-normal  because of  e 0

User · Answer

This may help you   Colorized ruby output

User · Answer

While the other answers will do the job fine for most people  the  correct  Unix way of doing this should be mentioned  Since all types of text terminals do not support these sequences  you can query the terminfo database  an abstraction over the capabilites of various text terminals   This might seem mostly of historical interest  ndash  software terminals in use today generally support the ANSI sequences  ndash  but it does have  at least  one practical effect  it is sometimes useful to be able to set the environment variable TERM to dumb to avoid all such styling  for example when saving the output to a text file   Also  it feels good to do things right   -    You can use the ruby-terminfo gem  It needs some C compiling to install  I was able to install it under my Ubuntu 14 10 system with     sudo apt-get install libncurses5-dev   gem install ruby-terminfo --user-install   Then you can query the database like this  see the terminfo man page for a list of what codes are available    require  terminfo   TermInfo control  bold   puts  Bold text  TermInfo control  sgr0   puts  Back to normal   puts  And now some     TermInfo control string  setaf   1           red    TermInfo control string  sgr0       text     Here s a little wrapper class I put together to make things a little more simple to use   require  terminfo   class Style   def self style          singleton     Style new   end    colors    w black red green yellow blue magenta cyan white    colors each with index do  color  index      define method color    get  setaf   index        define method  bg     color    get  setab   index      end    def bold    get  bold    end   def under   get  smul    end   def dim     get  dim     end   def clear   get  sgr0    end    def get  args      begin       TermInfo control string  args      rescue TermInfo  TermInfoError              end   end end   Usage   c   Style style C   c clear puts    c red Warning   C  this is   c bold way  C    c bg red too much   c cyan   c under styling  C    puts    c dim  Don t you think    C        edit  Finally  if you d rather not require a gem  you can rely on the tput program  as described here  ndash  Ruby example   puts  Hi       tput setaf 1     This is red      tput sgr0

User · Answer

Combining the answers above  you can implement something that works like the gem colorize without needing another dependency   class String     colorization   def colorize color code        e   color code m  self  e 0m    end    def red     colorize 31    end    def green     colorize 32    end    def yellow     colorize 33    end    def blue     colorize 34    end    def pink     colorize 35    end    def light blue     colorize 36    end end

User · Answer

I made this method that could help  It is not a big deal but it works   def colorize text  color    default   bgColor    default       colors     default    gt   38   black    gt   30   red    gt   31   green    gt   32   brown    gt   33    blue    gt   34    purple    gt   35         cyan    gt   36    gray    gt   37    dark gray    gt   1 30    light red    gt   1 31    light green    gt   1 32    yellow    gt   1 33          light blue    gt   1 34    light purple    gt   1 35    light cyan    gt   1 36    white    gt   1 37       bgColors     default    gt   0    black    gt   40    red    gt   41    green    gt   42    brown    gt   43    blue    gt   44         purple    gt   45    cyan    gt   46    gray    gt   47    dark gray    gt   100    light red    gt   101    light green    gt   102         yellow    gt   103    light blue    gt   104    light purple    gt   105    light cyan    gt   106    white    gt   107       color code   colors color      bgColor code   bgColors bgColor      return   033   bgColor code    color code m  text  033 0m  end   Here s how to use it   puts    colorize  Hello World     puts    colorize  Hello World    yellow     puts    colorize  Hello World    white   light red       Possible improvements could be    colors and bgColors are being defined each time the method is called and they don t change  Add other options like bold  underline  dim  etc    This method does not work for p  as p does an inspect to its argument  For example   p    colorize  Hello World       will show   e 0 38mHello World e 0m   I tested it with puts  print  and the Logger gem  and it works fine     I improved this and made a class so colors and bgColors are class constants and colorize is a class method   EDIT  Better code style  defined constants instead of class variables  using symbols instead of strings  added more options like  bold  italics  etc   class Colorizator     COLOURS     default   38   black   30   red   31   green   32   brown   33   blue   34   purple   35                   cyan   36   gray   37   dark gray   1 30   light red   1 31   light green   1 32   yellow   1 33                   light blue   1 34   light purple   1 35   light cyan   1 36   white   1 37    freeze     BG COLOURS     default   0   black   40   red   41   green   42   brown   43   blue   44                      purple   45   cyan   46   gray   47   dark gray   100   light red   101   light green   102                      yellow   103   light blue   104   light purple   105   light cyan   106   white   107    freeze      FONT OPTIONS     bold   1   dim   2   italic   3   underline   4   reverse   7   hidden   8    freeze      def self colorize text  colour    default  bg colour    default    options          colour code   COLOURS colour          bg colour code   BG COLOURS bg colour          font options   options select    k  v  v  amp  amp  FONT OPTIONS key  k    keys         font options   font options map    e  FONT OPTIONS e    join      squeeze         return   e   bg colour code    font options    colour code m  text  e 0m  squeeze          end end   You can use it by doing   Colorizator colorize  Hello World    gray   white Colorizator colorize  Hello World    light blue  bold  true Colorizator colorize  Hello World    light blue   white  bold  true  underline  true

User · Answer

Colorize is my favorite gem     -   Check it out   https   github com fazibear colorize  Installation   gem install colorize   Usage   require  colorize   puts  I am now red  red puts  I am now blue  blue puts  Testing  yellow

User · Answer

I wrote a little method to test out the basic color modes  based on answers by Erik Skoglund and others    outputs color table to console  regular and bold modes def colortable   names    w black red green yellow blue pink cyan white default    fgcodes    30  39  to a -  38     s        reg      e  d  dm s e 0m    bold     e 1  d  dm s e 0m    puts                         color table with these background codes     puts            40       41       42       43       44       45       46       47       49    names zip fgcodes  each   name fg      s      fg       puts   7s   name      reg     bold      9    fg 40 s fg 40 s   fg 41 s fg 41 s   fg 42 s fg 42 s   fg 43 s fg 43 s          fg 44 s fg 44 s   fg 45 s fg 45 s   fg 46 s fg 46 s   fg 47 s fg 47 s   fg 49 s fg 49 s       end   example output

User · Answer

Here s what I did to make it work without needing any gems   def red mytext      e 31m  mytext  e 0m    end puts red  hello world     Then only the text in the quotes there is colored  and you re returned to your regularly scheduled program

User · Answer

I found a few   http   github com ssoroka ansi tree master  Examples   puts ANSI color  red     hello there    puts ANSI color  green     Everything is green now    ANSI no color   http   flori github com term-ansicolor   Examples   print red  bold   red bold   reset    n  print red bold  red bold       n  print red   bold    red bold         n    http   github com sickill rainbow  Example   puts  this is red  foreground  red      and      this on yellow bg  background  yellow      and      even bright underlined   underline bright   If you are on Windows you may need to do a  gem install win32console  to enable support for colors   Also the article Colorizing console Ruby-script output is useful if you need to create your own gem  It explains how to add ANSI coloring to strings  You can use this knowledge to wrap it in some class that extends string or something

[ruby] How can I use Ruby to colorize the text output to a terminal?

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