2002-02-08 Yoshinori K. Okuji <okuji@enbug.org>

An internal pager is implemented.

	* stage2/builtins.c (pager_func): New function.
	(builtin_pager): New variable.
	(terminal_func): New option, "--lines=LINES" is added. If this
	option is specified, set MAX_LINES to the value. Otherwise, set
	MAX_LINES to 24.
	(vbeprobe_func): Remove the pager code specific to this
	function.
	(builtin_table): Added a pointer to BUILTIN_PAGER.
	* stage2/char_io.c (max_lines) [!STAGE1_5]: New variable.
	(count_lines) [!STAGE1_5]: Likewise.
	(use_pager) [!STAGE1_5]: Likewise.
	(grub_putchar) [!STAGE1_5]: if C is a newline and COUNT_LINES is
	not -1, count up the number of lines. If it exceeds the maximum
	number of lines minus 2, show a message and wait for input of
	return key. "minus 2" is to reserve space for the message
	printed by this internal pager.
	* stage2/cmdline.c (enter_cmdline): If USE_PAGER is true, set
	COUNT_LINES to zero, before running a command, and reset
	COUNT_LINES to -1 after that.
	* stage2/shared.h (max_lines) [!STAGE1_5]: Declared.
	(count_lines) [!STAGE1_5]: Likewise.
	(use_pager) [!STAGE1_5]: Likewise.

ChangeLog

@@ -1,3 +1,30 @@
+2002-02-08  Yoshinori K. Okuji  <okuji@enbug.org>
+
+	An internal pager is implemented.
+	
+	* stage2/builtins.c (pager_func): New function.
+	(builtin_pager): New variable.
+	(terminal_func): New option, "--lines=LINES" is added. If this
+	option is specified, set MAX_LINES to the value. Otherwise, set
+	MAX_LINES to 24.
+	(vbeprobe_func): Remove the pager code specific to this
+	function.
+	(builtin_table): Added a pointer to BUILTIN_PAGER.
+	* stage2/char_io.c (max_lines) [!STAGE1_5]: New variable.
+	(count_lines) [!STAGE1_5]: Likewise.
+	(use_pager) [!STAGE1_5]: Likewise.
+	(grub_putchar) [!STAGE1_5]: if C is a newline and COUNT_LINES is
+	not -1, count up the number of lines. If it exceeds the maximum
+	number of lines minus 2, show a message and wait for input of
+	return key. "minus 2" is to reserve space for the message
+	printed by this internal pager.
+	* stage2/cmdline.c (enter_cmdline): If USE_PAGER is true, set
+	COUNT_LINES to zero, before running a command, and reset
+	COUNT_LINES to -1 after that.
+	* stage2/shared.h (max_lines) [!STAGE1_5]: Declared.
+	(count_lines) [!STAGE1_5]: Likewise.
+	(use_pager) [!STAGE1_5]: Likewise.
+	
 2002-02-08  Yoshinori K. Okuji  <okuji@enbug.org>
 
 	* stage2/fsys_jfs.c (jfs_read) [STAGE1_5]: Set and reset

NEWS

@@ -12,6 +12,12 @@ New in 0.92:
   "savedefault") are hidden. If you want to see help messages for those
   commands, you will have to specify the names to "help" explicitly.
   (Also, note that <TAB> still shows all the commands.)
+* A built-in, `more'-like pager is added. When a command prints too many
+  lines to fit the screen, GRUB waits until you hit return key. This
+  feature can be turned off by the new command "pager".
+* The command "terminal" accepts a new option, "--lines=LINES". You can
+  set the maximum number of lines arbitrarily with this option. If you
+  don't specify it, the maximum number will be 24.
 
 New in 0.91 - 2002-01-21:
 * Support for Linux DAC960 is added.

stage2/builtins.c

@@ -2568,6 +2568,38 @@ static struct builtin builtin_modulenounzip =
   " disabled."
 };
 
+
+/* pager [on|off] */
+static int
+pager_func (char *arg, int flags)
+{
+  /* If ARG is empty, toggle the flag.  */
+  if (! *arg)
+    use_pager = ! use_pager;
+  else if (grub_memcmp (arg, "on", 2) == 0)
+    use_pager = 1;
+  else if (grub_memcmp (arg, "off", 3) == 0)
+    use_pager = 0;
+  else
+    {
+      errnum = ERR_BAD_ARGUMENT;
+      return 1;
+    }
+
+  grub_printf (" Internal pager is now %s\n", use_pager ? "on" : "off");
+  return 0;
+}
+
+static struct builtin builtin_pager =
+{
+  "pager",
+  pager_func,
+  BUILTIN_CMDLINE | BUILTIN_MENU | BUILTIN_HELP_LIST,
+  "pager [FLAG]",
+  "Toggle pager mode with no argument. If FLAG is given and its value"
+  " is `on', turn on the mode. If FLAG is `off', turn off the mode."
+};
+
 
 /* partnew PART TYPE START LEN */
 static int
@@ -3866,6 +3898,7 @@ terminal_func (char *arg, int flags)
   int to = -1;
   int dumb = 0;
   int saved_terminal = terminal;
+  int lines = 0;
 
   /* Get GNU-style long options.  */
   while (1)
@@ -3879,6 +3912,20 @@ terminal_func (char *arg, int flags)
 	  if (! safe_parse_maxint (&val, &to))
 	    return 1;
 	}
+      else if (grub_memcmp (arg, "--lines=", sizeof ("--lines=") - 1) == 0)
+	{
+	  char *val = arg + sizeof ("--lines=") - 1;
+
+	  if (! safe_parse_maxint (&val, &lines))
+	    return 1;
+
+	  /* Probably less than four is meaningless....  */
+	  if (lines < 4)
+	    {
+	      errnum = ERR_BAD_ARGUMENT;
+	      return 1;
+	    }
+	}
       else
 	break;
 
@@ -3998,6 +4045,12 @@ terminal_func (char *arg, int flags)
     }
 #endif /* SUPPORT_SERIAL */
 
+  if (lines)
+    max_lines = lines;
+  else
+    /* 24 would be a good default value.  */
+    max_lines = 24;
+  
   return 0;
 }
 
@@ -4006,14 +4059,14 @@ static struct builtin builtin_terminal =
   "terminal",
   terminal_func,
   BUILTIN_MENU | BUILTIN_CMDLINE | BUILTIN_HELP_LIST,
-  "terminal [--dumb] [--timeout=SECS] [console] [serial]",
+  "terminal [--dumb] [--timeout=SECS] [--lines=LINES] [console] [serial]",
   "Select a terminal. When serial is specified, wait until you push any key"
   " to continue. If both console and serial are specified, the terminal"
   " to which you input a key first will be selected. If no argument is"
-  " specified, print current setting. The option --dumb speicifies that"
+  " specified, print current setting. The option --dumb specifies that"
   " your terminal is dumb, otherwise, vt100-compatibility is assumed."
   " If --timeout is present, this command will wait at most for SECS"
-  " seconds."
+  " seconds. The option --lines specifies the maximum number of lines."
 };
 #endif /* SUPPORT_SERIAL || SUPPORT_HERCULES */
 
@@ -4334,7 +4387,6 @@ vbeprobe_func (char *arg, int flags)
   struct vbe_controller controller;
   unsigned short *mode_list;
   int mode_number = -1;
-  int count = 1;
   
   auto unsigned long vbe_far_ptr_to_linear (unsigned long);
   
@@ -4416,16 +4468,6 @@ vbeprobe_func (char *arg, int flags)
 	  
 	  if (mode_number != -1)
 	    break;
-
-	  count++;
-
-	  /* XXX: arbitrary.  */
-	  if (count == 22)
-	    {
-	      grub_printf ("\nHit any key to continue.\n");
-	      count = 0;
-	      getkey ();
-	    }
 	}
     }
 
@@ -4494,6 +4536,7 @@ struct builtin *builtin_table[] =
 #endif /* USE_MD5_PASSWORDS */
   &builtin_module,
   &builtin_modulenounzip,
+  &builtin_pager,
   &builtin_partnew,
   &builtin_parttype,
   &builtin_password,

stage2/char_io.c

@@ -1,7 +1,7 @@
 /* char_io.c - basic console input and output */
 /*
  *  GRUB  --  GRand Unified Bootloader
- *  Copyright (C) 1999, 2000, 2001  Free Software Foundation, Inc.
+ *  Copyright (C) 1999,2000,2001,2002  Free Software Foundation, Inc.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -30,6 +30,9 @@
 
 #ifndef STAGE1_5
 int auto_fill = 1;
+int max_lines = 24;
+int count_lines = -1;
+int use_pager = 1;
 #endif
 
 void
@@ -1123,6 +1126,34 @@ grub_putchar (int c)
 
       col++;
     }
+  else if (c == '\n')
+    {
+      /* Internal `more'-like feature.  */
+      if (count_lines != -1)
+	{
+	  count_lines++;
+	  if (count_lines >= max_lines - 2)
+	    {
+	      int tmp;
+	      
+	      /* It's important to disable the feature temporarily, because
+		 the following grub_printf call will print newlines.  */
+	      count_lines = -1;
+	      
+	      grub_printf ("\n\n[Hit return to continue]");
+	      do
+		{
+		  tmp = ASCII_CHAR (getkey ());
+		}
+	      while (tmp != '\n' && tmp != '\r');
+	      grub_printf ("\n\n");
+	      
+	      /* Restart to count lines.  */
+	      count_lines = 0;
+	      return;
+	    }
+	}
+    }
 
   if (terminal & TERMINAL_CONSOLE)
     console_putchar (c);

stage2/cmdline.c

@@ -162,9 +162,16 @@ enter_cmdline (char *heap, int forever)
 	 disks.  */
       buf_drive = -1;
 
+      /* Start to count lines, only if the internal pager is in use.  */
+      if (use_pager)
+	count_lines = 0;
+      
       /* Run BUILTIN->FUNC.  */
       arg = skip_to (1, heap);
       (builtin->func) (arg, BUILTIN_CMDLINE);
+
+      /* Finish the line count.  */
+      count_lines = -1;
     }
 }
 

stage2/shared.h

@@ -608,6 +608,11 @@ extern char *password;
 extern password_t password_type;
 extern int auth;
 extern char commands[];
+
+/* For `more'-like feature.  */
+extern int max_lines;
+extern int count_lines;
+extern int use_pager;
 #endif
 
 #ifndef NO_DECOMPRESSION