Initial revision

git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@2 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

6 files changed, 1019 insertions, 0 deletions

diff --git a/ext/curses/MANIFEST b/ext/curses/MANIFEST
new file mode 100644
index 000000000..db5e54ffe
--- /dev/null
+++ b/ext/curses/MANIFEST
@@ -0,0 +1,6 @@
+MANIFEST
+curses.c
+extconf.rb
+hello.rb
+rain.rb
+view.rb
diff --git a/ext/curses/curses.c b/ext/curses/curses.c
new file mode 100644
index 000000000..6e8e49684
--- /dev/null
+++ b/ext/curses/curses.c
@@ -0,0 +1,798 @@
+/*
+ * ext/curses/curses.c
+ * 
+ * by MAEDA Shugo (ender@pic-internet.or.jp)
+ * modified by Yukihiro Matsumoto (matz@ruby.club.or.jp)
+ */
+
+#ifdef HAVE_NCURSES_H
+# include <ncurses.h>
+#else
+# ifdef HAVE_NCURSES_CURSES_H
+#  include <ncurses/curses.h>
+# else
+#  include <curses.h>
+#  if defined(__NetBSD__) && !defined(_maxx)
+#   define _maxx maxx
+#  endif
+#  if defined(__NetBSD__) && !defined(_maxy)
+#   define _maxy maxy
+#  endif
+# endif
+#endif
+
+#include "ruby.h"
+
+static VALUE mCurses;
+static VALUE cWindow;
+
+VALUE rb_stdscr;
+
+struct windata {
+    WINDOW *window;
+};
+
+#define NUM2CHAR(x) (char)NUM2INT(x)
+#define CHAR2FIX(x) INT2FIX((int)x)
+
+static void
+no_window()
+{
+    Fail("already closed window");
+}
+
+#define GetWINDOW(obj, winp) {\
+    Data_Get_Struct(obj, struct windata, winp);\
+    if (winp->window == 0) no_window();\
+}
+
+static void
+curses_err()
+{
+    Fail("curses error");
+}
+
+#define CHECK(c) if ((c)==ERR) {curses_err();}
+
+static void
+free_window(winp)
+    struct windata *winp;
+{
+    if (winp->window && winp->window != stdscr) delwin(winp->window);
+    winp->window = 0;
+}
+
+static VALUE
+prep_window(class, window)
+    VALUE class;
+    WINDOW *window;
+{
+    VALUE obj;
+    struct windata *winp;
+
+    if (window == NULL) {
+	Fail("failed to create window");
+    }
+
+    obj = Data_Make_Struct(class, struct windata, 0, free_window, winp);
+    winp->window = window;
+    
+    return obj;    
+}
+
+/*-------------------------- module Curses --------------------------*/
+
+/* def init_screen */
+static VALUE
+curses_init_screen()
+{
+    initscr();
+    if (stdscr == 0) {
+	Fail("cannot initialize curses");
+    }
+    clear();
+    rb_stdscr = prep_window(cWindow, stdscr);
+    return Qnil;
+}
+
+/* def stdscr */
+static VALUE
+curses_stdscr()
+{
+    if (!rb_stdscr) curses_init_screen();
+    return rb_stdscr;
+}
+
+/* def close_screen */
+static VALUE
+curses_close_screen()
+{
+    CHECK(endwin());
+    return Qnil;
+}
+
+/* def closed? */
+static VALUE
+curses_closed()
+{
+#ifdef HAVE_ENDWIN
+    if (isendwin()) {
+	return TRUE;
+    }
+    return FALSE;
+#else
+    rb_notimplement();
+#endif
+}
+
+/* def clear */
+static VALUE
+curses_clear(obj)
+    VALUE obj;
+{
+    wclear(stdscr);
+    return Qnil;
+}
+
+/* def refresh */
+static VALUE
+curses_refresh(obj)
+    VALUE obj;
+{
+    CHECK(refresh());
+    return Qnil;
+}
+
+/* def refresh */
+static VALUE
+curses_doupdate(obj)
+    VALUE obj;
+{
+    CHECK(doupdate());
+    return Qnil;
+}
+
+/* def echo */
+static VALUE
+curses_echo(obj)
+    VALUE obj;
+{
+    CHECK(echo());
+    return Qnil;
+}
+
+/* def noecho */
+static VALUE
+curses_noecho(obj)
+    VALUE obj;
+{
+    CHECK(noecho());
+    return Qnil;
+}
+
+/* def raw */
+static VALUE
+curses_raw(obj)
+    VALUE obj;
+{
+    CHECK(raw());
+    return Qnil;
+}
+
+/* def noraw */
+static VALUE
+curses_noraw(obj)
+    VALUE obj;
+{
+    CHECK(noraw());
+    return Qnil;
+}
+
+/* def cbreak */
+static VALUE
+curses_cbreak(obj)
+    VALUE obj;
+{
+    CHECK(cbreak());
+    return Qnil;
+}
+
+/* def nocbreak */
+static VALUE
+curses_nocbreak(obj)
+    VALUE obj;
+{
+    CHECK(nocbreak());
+    return Qnil;
+}
+
+/* def nl */
+static VALUE
+curses_nl(obj)
+    VALUE obj;
+{
+    CHECK(nl());
+    return Qnil;
+}
+
+/* def nonl */
+static VALUE
+curses_nonl(obj)
+    VALUE obj;
+{
+    CHECK(nonl());
+    return Qnil;
+}
+
+/* def beep */
+static VALUE
+curses_beep(obj)
+    VALUE obj;
+{
+#ifdef HAVE_BEEP
+    beep();
+#endif
+    return Qnil;
+}
+
+/* def flash */
+static VALUE
+curses_flash(obj)
+    VALUE obj;
+{
+    flash();
+    return Qnil;
+}
+
+/* def ungetch */
+static VALUE
+curses_ungetch(obj, ch)
+    VALUE obj;
+    VALUE ch;
+{
+#ifdef HAVE_UNGETCH
+    CHECK(ungetch(NUM2INT(ch)));
+#else
+    rb_notimplement();
+#endif
+    return Qnil;
+}
+
+/* def setpos(y, x) */
+static VALUE
+curses_setpos(obj, y, x)
+    VALUE obj;
+    VALUE y;
+    VALUE x;
+{
+    CHECK(move(NUM2INT(y), NUM2INT(x)));
+    return Qnil;
+}
+
+/* def standout */
+static VALUE
+curses_standout(obj)
+    VALUE obj;
+{
+    standout();
+    return Qnil;
+}
+
+/* def standend */
+static VALUE
+curses_standend(obj)
+    VALUE obj;
+{
+    standend();
+    return Qnil;
+}
+
+/* def inch */
+static VALUE
+curses_inch(obj)
+    VALUE obj;
+{
+    return CHAR2FIX(inch());
+}
+
+/* def addch(ch) */
+static VALUE
+curses_addch(obj, ch)
+    VALUE obj;
+    VALUE ch;
+{
+    CHECK(addch(NUM2CHAR(ch)));
+    return Qnil;
+}
+
+/* def insch(ch) */
+static VALUE
+curses_insch(obj, ch)
+    VALUE obj;
+    VALUE ch;
+{
+    CHECK(insch(NUM2CHAR(ch)));
+    return Qnil;
+}
+
+/* def addstr(str) */
+static VALUE
+curses_addstr(obj, str)
+    VALUE obj;
+    VALUE str;
+{
+    addstr(RSTRING(str)->ptr);
+    return Qnil;
+}
+
+/* def getch */
+static VALUE
+curses_getch(obj)
+    VALUE obj;
+{
+    return CHAR2FIX(getch());
+}
+
+/* def getstr */
+static VALUE
+curses_getstr(obj)
+    VALUE obj;
+{
+    char rtn[1024]; /* This should be big enough.. I hope */
+    CHECK(getstr(rtn));
+    return str_taint(str_new2(rtn));
+}
+
+/* def delch */
+static VALUE
+curses_delch(obj)
+    VALUE obj;
+{
+    CHECK(delch());
+    return Qnil;
+}
+
+/* def delelteln */
+static VALUE
+curses_deleteln(obj)
+    VALUE obj;
+{
+    CHECK(deleteln());
+    return Qnil;
+}
+
+static VALUE
+curses_lines()
+{
+    return INT2FIX(LINES);
+}
+
+static VALUE
+curses_cols()
+{
+    return INT2FIX(COLS);
+}
+
+/*-------------------------- class Window --------------------------*/
+
+/* def new(lines, cols, top, left) */
+static VALUE
+window_s_new(class, lines, cols, top, left)
+    VALUE class;
+    VALUE lines;
+    VALUE cols;
+    VALUE top;
+    VALUE left;
+{
+    WINDOW *window;
+    
+    window = newwin(NUM2INT(lines), NUM2INT(cols), NUM2INT(top), NUM2INT(left));
+    wclear(window);
+    return prep_window(class, window);
+}
+
+/* def subwin(lines, cols, top, left) */
+static VALUE
+window_subwin(obj, lines, cols, top, left)
+    VALUE obj;
+    VALUE lines;
+    VALUE cols;
+    VALUE top;
+    VALUE left;
+{
+    struct windata *winp;
+    WINDOW *window;
+
+    GetWINDOW(obj, winp);
+    window = subwin(winp->window, NUM2INT(lines), NUM2INT(cols),
+		                  NUM2INT(top), NUM2INT(left));
+    return prep_window(cWindow, window);
+}
+
+/* def close */
+static VALUE
+window_close(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    free_window(winp);
+
+    return Qnil;
+}
+
+/* def clear */
+static VALUE
+window_clear(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    wclear(winp->window);
+    
+    return Qnil;
+}
+
+/* def refresh */
+static VALUE
+window_refresh(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(wrefresh(winp->window));
+    
+    return Qnil;
+}
+
+/* def box(vert, hor) */
+static VALUE
+window_box(obj, vert, hor)
+    VALUE obj;
+    VALUE vert;
+    VALUE hor;
+{
+    struct windata *winp; 
+   
+    GetWINDOW(obj, winp);
+    box(winp->window, NUM2CHAR(vert), NUM2CHAR(hor));
+    
+    return Qnil;
+}
+
+
+/* def move(y, x) */
+static VALUE
+window_move(obj, y, x)
+    VALUE obj;
+    VALUE y;
+    VALUE x;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(mvwin(winp->window, NUM2INT(y), NUM2INT(x)));
+
+    return Qnil;
+}
+
+/* def setpos(y, x) */
+static VALUE
+window_setpos(obj, y, x)
+    VALUE obj;
+    VALUE y;
+    VALUE x;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(wmove(winp->window, NUM2INT(y), NUM2INT(x)));
+    return Qnil;
+}
+
+/* def cury */
+static VALUE
+window_cury(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    int x, y;
+
+    GetWINDOW(obj, winp);
+    getyx(winp->window, y, x);
+    return INT2FIX(y);
+}
+
+/* def curx */
+static VALUE
+window_curx(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    int x, y;
+
+    GetWINDOW(obj, winp);
+    getyx(winp->window, y, x);
+    return INT2FIX(x);
+}
+
+/* def maxy */
+static VALUE
+window_maxy(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    int x, y;
+
+    GetWINDOW(obj, winp);
+#ifdef getmaxy
+    return INT2FIX(getmaxy(winp->window));
+#else
+#ifdef getmaxyx
+    getmaxyx(winp->window, y, x);
+    return INT2FIX(y);
+#else
+    return INT2FIX(winp->window->_maxy+1);
+#endif
+#endif
+}
+
+/* def maxx */
+static VALUE
+window_maxx(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    int x, y;
+
+    GetWINDOW(obj, winp);
+#ifdef getmaxx
+    return INT2FIX(getmaxx(winp->window));
+#else
+#ifdef getmaxyx
+    getmaxyx(winp->window, y, x);
+    return INT2FIX(x);
+#else
+    return INT2FIX(winp->window->_maxx+1);
+#endif
+#endif
+}
+
+/* def begy */
+static VALUE
+window_begy(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    int x, y;
+
+    GetWINDOW(obj, winp);
+#ifdef getbegyx
+    getbegyx(winp->window, y, x);
+    return INT2FIX(y);
+#else
+    return INT2FIX(winp->window->_begy);
+#endif
+}
+
+/* def begx */
+static VALUE
+window_begx(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    int x, y;
+
+    GetWINDOW(obj, winp);
+#ifdef getbegyx
+    getbegyx(winp->window, y, x);
+    return INT2FIX(x);
+#else
+    return INT2FIX(winp->window->_begx);
+#endif
+}
+
+/* def standout */
+static VALUE
+window_standout(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    wstandout(winp->window);
+    return Qnil;
+}
+
+/* def standend */
+static VALUE
+window_standend(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    wstandend(winp->window);
+    return Qnil;
+}
+
+/* def inch */
+static VALUE
+window_inch(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    return CHAR2FIX(winch(winp->window));
+}
+
+/* def addch(ch) */
+static VALUE
+window_addch(obj, ch)
+    VALUE obj;
+    VALUE ch;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(waddch(winp->window, NUM2CHAR(ch)));
+    
+    return Qnil;
+}
+
+/* def insch(ch) */
+static VALUE
+window_insch(obj, ch)
+    VALUE obj;
+    VALUE ch;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(winsch(winp->window, NUM2CHAR(ch)));
+    
+    return Qnil;
+}
+
+/* def addstr(str) */
+static VALUE
+window_addstr(obj, str)
+    VALUE obj;
+    VALUE str;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(waddstr(winp->window, RSTRING(str)->ptr));
+    
+    return Qnil;
+}
+
+/* def <<(str) */
+static VALUE
+window_addstr2(obj, str)
+    VALUE obj;
+    VALUE str;
+{
+    window_addstr(obj, str);
+    return obj;
+}
+
+/* def getch */
+static VALUE
+window_getch(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    return CHAR2FIX(wgetch(winp->window));
+}
+
+/* def getstr */
+static VALUE
+window_getstr(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    char rtn[1024]; /* This should be big enough.. I hope */
+    
+    GetWINDOW(obj, winp);
+    CHECK(wgetstr(winp->window, rtn));
+    return str_taint(str_new2(rtn));
+}
+
+/* def delch */
+static VALUE
+window_delch(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(wdelch(winp->window));
+    return Qnil;
+}
+
+/* def delelteln */
+static VALUE
+window_deleteln(obj)
+    VALUE obj;
+{
+    struct windata *winp;
+    
+    GetWINDOW(obj, winp);
+    CHECK(wdeleteln(winp->window));
+    return Qnil;
+}
+
+/*------------------------- Initialization -------------------------*/
+void
+Init_curses()
+{
+    mCurses = rb_define_module("Curses");
+    rb_define_module_function(mCurses, "init_screen", curses_init_screen, 0);
+    rb_define_module_function(mCurses, "close_screen", curses_close_screen, 0);
+    rb_define_module_function(mCurses, "closed?", curses_closed, 0);
+    rb_define_module_function(mCurses, "stdscr", curses_stdscr, 0);
+    rb_define_module_function(mCurses, "refresh", curses_refresh, 0);
+    rb_define_module_function(mCurses, "doupdate", curses_doupdate, 0);
+    rb_define_module_function(mCurses, "clear", curses_clear, 0);
+    rb_define_module_function(mCurses, "echo", curses_echo, 0);
+    rb_define_module_function(mCurses, "noecho", curses_noecho, 0);
+    rb_define_module_function(mCurses, "raw", curses_raw, 0);
+    rb_define_module_function(mCurses, "noraw", curses_noraw, 0);
+    rb_define_module_function(mCurses, "cbreak", curses_cbreak, 0);
+    rb_define_module_function(mCurses, "nocbreak", curses_nocbreak, 0);
+    rb_define_alias(mCurses, "crmode", "cbreak");
+    rb_define_alias(mCurses, "nocrmode", "nocbreak");
+    rb_define_module_function(mCurses, "nl", curses_nl, 0);
+    rb_define_module_function(mCurses, "nonl", curses_nonl, 0);
+    rb_define_module_function(mCurses, "beep", curses_beep, 0);
+    rb_define_module_function(mCurses, "flash", curses_flash, 0);
+    rb_define_module_function(mCurses, "ungetch", curses_ungetch, 1);
+    rb_define_module_function(mCurses, "setpos", curses_setpos, 2);
+    rb_define_module_function(mCurses, "standout", curses_standout, 0);
+    rb_define_module_function(mCurses, "standend", curses_standend, 0);
+    rb_define_module_function(mCurses, "inch", curses_inch, 0);
+    rb_define_module_function(mCurses, "addch", curses_addch, 1);
+    rb_define_module_function(mCurses, "insch", curses_insch, 1);
+    rb_define_module_function(mCurses, "addstr", curses_addstr, 1);
+    rb_define_module_function(mCurses, "getch", curses_getch, 0);
+    rb_define_module_function(mCurses, "getstr", curses_getstr, 0);
+    rb_define_module_function(mCurses, "delch", curses_delch, 0);
+    rb_define_module_function(mCurses, "deleteln", curses_deleteln, 0);
+    rb_define_module_function(mCurses, "lines", curses_lines, 0);
+    rb_define_module_function(mCurses, "cols", curses_cols, 0);
+    
+    cWindow = rb_define_class_under(mCurses, "Window", cObject);
+    rb_define_singleton_method(cWindow, "new", window_s_new, 4);
+    rb_define_method(cWindow, "subwin", window_subwin, 4);
+    rb_define_method(cWindow, "close", window_close, 0);
+    rb_define_method(cWindow, "clear", window_clear, 0);
+    rb_define_method(cWindow, "refresh", window_refresh, 0);
+    rb_define_method(cWindow, "box", window_box, 2);
+    rb_define_method(cWindow, "move", window_move, 2);
+    rb_define_method(cWindow, "setpos", window_setpos, 2);
+    rb_define_method(cWindow, "cury", window_cury, 0);
+    rb_define_method(cWindow, "curx", window_curx, 0);
+    rb_define_method(cWindow, "maxy", window_maxy, 0);
+    rb_define_method(cWindow, "maxx", window_maxx, 0);
+    rb_define_method(cWindow, "begy", window_begy, 0);
+    rb_define_method(cWindow, "begx", window_begx, 0);
+    rb_define_method(cWindow, "standout", window_standout, 0);
+    rb_define_method(cWindow, "standend", window_standend, 0);
+    rb_define_method(cWindow, "inch", window_inch, 0);
+    rb_define_method(cWindow, "addch", window_addch, 1);
+    rb_define_method(cWindow, "insch", window_insch, 1);
+    rb_define_method(cWindow, "addstr", window_addstr, 1);
+    rb_define_method(cWindow, "<<", window_addstr2, 1);
+    rb_define_method(cWindow, "getch", window_getch, 0);
+    rb_define_method(cWindow, "getstr", window_getstr, 0);
+    rb_define_method(cWindow, "delch", window_delch, 0);
+    rb_define_method(cWindow, "deleteln", window_deleteln, 0);
+}
diff --git a/ext/curses/extconf.rb b/ext/curses/extconf.rb
new file mode 100644
index 000000000..9b2843784
--- /dev/null
+++ b/ext/curses/extconf.rb
@@ -0,0 +1,21 @@
+$CFLAGS="-I/usr/include/ncurses -I/usr/local/include/ncurses"
+$LDFLAGS="-L/usr/local/lib"
+make=FALSE
+if have_header("ncurses.h") and have_library("ncurses", "initscr")
+  make=TRUE
+elsif have_header("ncurses/curses.h") and have_library("ncurses", "initscr")
+  make=TRUE
+else
+  $CFLAGS=nil
+  have_library("termcap", "tgetent") 
+  if have_library("curses", "initscr")
+    make=TRUE
+  end
+end
+
+if make then
+  for f in ["isendwin", "ungetch", "beep"]
+    have_func(f)
+  end
+  create_makefile("curses")
+end
diff --git a/ext/curses/hello.rb b/ext/curses/hello.rb
new file mode 100644
index 000000000..bed7779aa
--- /dev/null
+++ b/ext/curses/hello.rb
@@ -0,0 +1,28 @@
+#!/usr/local/bin/ruby
+
+require "curses"
+include Curses
+
+def show_message(message)
+  width = message.length + 6
+  win = Window.new(5, width,
+		   (lines - 5) / 2, (cols - width) / 2)
+  win.box(?|, ?=)
+  win.setpos(2, 3)
+  win.addstr(message)
+  win.getch
+  win.close
+end
+
+init_screen
+begin
+  crmode
+#  show_message("Hit any key")
+  setpos (lines - 5) / 2, (cols - 10) / 2
+  addstr("Hit any key")
+  getch
+  show_message("Hello, World!")
+  refresh
+ensure
+  close_screen
+end
diff --git a/ext/curses/rain.rb b/ext/curses/rain.rb
new file mode 100644
index 000000000..36f0f84de
--- /dev/null
+++ b/ext/curses/rain.rb
@@ -0,0 +1,76 @@
+#!/usr/local/bin/ruby
+# rain for a curses test
+
+require "curses"
+include Curses
+
+def onsig(sig)
+  close_screen
+  exit sig
+end
+
+def ranf
+  rand(32767).to_f / 32767
+end
+
+# main #
+for i in 1 .. 15  # SIGHUP .. SIGTERM
+  if trap(i, "SIG_IGN") != 0 then  # 0 for SIG_IGN
+    trap(i) {|sig| onsig(sig) }
+  end
+end
+
+init_screen
+nl
+noecho
+srand
+
+xpos = {}
+ypos = {}
+r = lines - 4
+c = cols - 4
+for i in 0 .. 4
+  xpos[i] = (c * ranf).to_i + 2
+  ypos[i] = (r * ranf).to_i + 2
+end
+
+i = 0
+while TRUE
+  x = (c * ranf).to_i + 2
+  y = (r * ranf).to_i + 2
+
+
+  setpos(y, x); addstr(".")
+
+  setpos(ypos[i], xpos[i]); addstr("o")
+
+  i = if i == 0 then 4 else i - 1 end
+  setpos(ypos[i], xpos[i]); addstr("O")
+
+  i = if i == 0 then 4 else i - 1 end
+  setpos(ypos[i] - 1, xpos[i]);      addstr("-")
+  setpos(ypos[i],     xpos[i] - 1); addstr("|.|")
+  setpos(ypos[i] + 1, xpos[i]);      addstr("-")
+
+  i = if i == 0 then 4 else i - 1 end
+  setpos(ypos[i] - 2, xpos[i]);       addstr("-")
+  setpos(ypos[i] - 1, xpos[i] - 1);  addstr("/ \\")
+  setpos(ypos[i],     xpos[i] - 2); addstr("| O |")
+  setpos(ypos[i] + 1, xpos[i] - 1); addstr("\\ /")
+  setpos(ypos[i] + 2, xpos[i]);       addstr("-")
+
+  i = if i == 0 then 4 else i - 1 end
+  setpos(ypos[i] - 2, xpos[i]);       addstr(" ")
+  setpos(ypos[i] - 1, xpos[i] - 1);  addstr("   ")
+  setpos(ypos[i],     xpos[i] - 2); addstr("     ")
+  setpos(ypos[i] + 1, xpos[i] - 1);  addstr("   ")
+  setpos(ypos[i] + 2, xpos[i]);       addstr(" ")
+
+
+  xpos[i] = x
+  ypos[i] = y
+  refresh
+  sleep(0.5)
+end
+
+# end of main
diff --git a/ext/curses/view.rb b/ext/curses/view.rb
new file mode 100644
index 000000000..e59a74ed4
--- /dev/null
+++ b/ext/curses/view.rb
@@ -0,0 +1,90 @@
+#!/usr/local/bin/ruby
+
+require "curses"
+include Curses
+
+#
+# main
+#
+
+if ARGV.size != 1 then
+  printf("usage: view file\n");
+  exit
+end
+begin
+  fp = open(ARGV[0], "r")
+rescue
+  raise "cannot open file: #{ARGV[1]}"
+end
+
+# signal(SIGINT, finish)
+
+init_screen
+#keypad(stdscr, TRUE)
+nonl
+cbreak
+noecho
+#scrollok(stdscr, TRUE)
+
+# slurp the file
+data_lines = []
+fp.each_line { |l|
+  data_lines.push(l)
+}
+fp.close
+
+
+lptr = 0
+while TRUE
+  i = 0
+  while i < lines
+    setpos(i, 0)
+    #clrtoeol
+    addstr(data_lines[lptr + i]) #if data_lines[lptr + i]
+    i += 1
+  end
+
+  explicit = FALSE
+  n = 0
+  while TRUE
+    c = getch.chr
+    if c =~ "[0-9]" then
+      n = 10 * n + c.to_i
+    else
+      break
+    end
+  end
+
+  n = 1 if !explicit && n == 0
+
+  case c
+  when "n"  #when KEY_DOWN
+    i = 0
+    while i < n
+      if lptr + lines < data_lines.size then
+	lptr += 1
+      else
+	break
+      end
+      i += 1 
+    end
+    #wscrl(i)
+      
+  when "p"  #when KEY_UP
+    i = 0
+    while i < n
+      if lptr > 0 then
+	lptr -= 1
+      else
+	break
+      end
+      i += 1 
+    end    
+    #wscrl(-i)
+
+  when "q"
+    break
+  end
+
+end
+close_screen