ext/curses/view.rb

DEFINITIONS

   1  #!/usr/local/bin/ruby
   2  
   3  require "curses"
   4  include Curses
   5  
   6  #
   7  # main
   8  #
   9  
  10  if ARGV.size != 1 then
  11    printf("usage: view file\n");
  12    exit
  13  end
  14  begin
  15    fp = open(ARGV[0], "r")
  16  rescue
  17    raise "cannot open file: #{ARGV[1]}"
  18  end
  19  
  20  # signal(SIGINT, finish)
  21  
  22  init_screen
  23  #keypad(stdscr, TRUE)
  24  nonl
  25  cbreak
  26  noecho
  27  #scrollok(stdscr, TRUE)
  28  
  29  # slurp the file
  30  data_lines = []
  31  fp.each_line { |l|
  32    data_lines.push(l)
  33  }
  34  fp.close
  35  
  36  
  37  lptr = 0
  38  while TRUE
  39    i = 0
  40    while i < lines
  41      setpos(i, 0)
  42      #clrtoeol
  43      addstr(data_lines[lptr + i]) #if data_lines[lptr + i]
  44      i += 1
  45    end
  46    refresh
  47  
  48    explicit = FALSE
  49    n = 0
  50    while TRUE
  51      c = getch.chr
  52      if c =~ "[0-9]" then
  53        n = 10 * n + c.to_i
  54      else
  55        break
  56      end
  57    end
  58  
  59    n = 1 if !explicit && n == 0
  60  
  61    case c
  62    when "n"  #when KEY_DOWN
  63      i = 0
  64      while i < n
  65        if lptr + lines < data_lines.size then
  66          lptr += 1
  67        else
  68          break
  69        end
  70        i += 1 
  71      end
  72      #wscrl(i)
  73        
  74    when "p"  #when KEY_UP
  75      i = 0
  76      while i < n
  77        if lptr > 0 then
  78          lptr -= 1
  79        else
  80          break
  81        end
  82        i += 1 
  83      end    
  84      #wscrl(-i)
  85  
  86    when "q"
  87      break
  88    end
  89  
  90  end
  91  close_screen