1  
   2  
   3  # move cursor to beginning of line
   4  cr = "\r"           
   5  
   6  
   7  # ANSI escape code to clear line from cursor to end of line
   8  # "\e" is an alternative to "\033"
   9  # cf. http://en.wikipedia.org/wiki/ANSI_escape_code
  10  
  11  clear = "\e[0K"     
  12  
  13  # reset lines
  14  reset = cr + clear
  15  
  16  
  17  
  18  #-------------------------------- Example 1 --------------------------------
  19  
  20  
  21  (1..100).each do |i| 
  22    print "#{reset}#{i}%"
  23    sleep(0.08)
  24    $stdout.flush
  25  end
  26  
  27  print "#{reset}"     # clear current line
  28  
  29  $stdout.flush
  30  puts "done"
  31  
  32  
  33  
  34  #-------------------------------- Example 2 --------------------------------
  35  
  36  
  37  chars = [ "|", "/", "-", "\\" ]
  38  
  39  # 7 turns on reverse video mode, 31 red , ...
  40  n = 31
  41  
  42  str = "#{reset}\e[#{n};1m"   
  43  
  44  
  45  (1..100).each do |i| 
  46  
  47     case i
  48        when   0..10    then print "#{str}#{chars[0]}"
  49        when  10..20    then print "#{str}#{chars[1]}"
  50        when  20..30    then print "#{str}#{chars[2]}"
  51        when  30..40    then print "#{str}#{chars[3]}"
  52        when  40..50    then print "#{str}#{chars[0]}"
  53        when  50..60    then print "#{str}#{chars[1]}"
  54        when  60..70    then print "#{str}#{chars[2]}"
  55        when  70..80    then print "#{str}#{chars[3]}"
  56        when  80..90    then print "#{str}#{chars[0]}"
  57        when  90..100   then print "#{str}#{chars[1]}"
  58     end
  59  
  60     sleep(0.1)
  61     $stdout.flush
  62  
  63  end
  64  
  65  print "\e[0m"
  66  print "#{reset}" 
  67  
  68  $stdout.flush
  69  puts "done"
  70  
  71  
  72  
  73  #-------------------------------- Example 3 --------------------------------
  74  
  75  
  76  MAX = 80 
  77  
  78  $stdout.sync = true     # alternative to $stdout.flush below
  79  
  80  10.times do
  81     foo_string = Time.now.to_s
  82     s = foo_string[0..MAX].center(MAX)   # or rjust or ljust 
  83     print cr + s 
  84     #$stdout.flush 
  85     sleep(1.1)
  86  end
  87  
  88  print "\e[0m" 
  89  print "#{reset}" 
  90  
  91  $stdout.flush
  92  puts "done"
  93  
  94