editors/vi.c

/* vi: set sw=8 ts=8: */
/*
 * tiny vi.c: A small 'vi' clone
 * Copyright (C) 2000, 2001 Sterling Huxley <sterling@europa.com>
 *
 *  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
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

static const char vi_Version[] =
	"$Id: vi.c,v 1.35 2004/03/31 11:12:51 andersen Exp $";

/*
 * To compile for standalone use:
 *	gcc -Wall -Os -s -DSTANDALONE -o vi vi.c
 *	  or
 *	gcc -Wall -Os -s -DSTANDALONE -DCONFIG_FEATURE_VI_CRASHME -o vi vi.c		# include testing features
 *	strip vi
 */

/*
 * Things To Do:
 *	EXINIT
 *	$HOME/.exrc  and  ./.exrc
 *	add magic to search	/foo.*bar
 *	add :help command
 *	:map macros
 *	how about mode lines:   vi: set sw=8 ts=8:
 *	if mark[] values were line numbers rather than pointers
 *	   it would be easier to change the mark when add/delete lines
 *	More intelligence in refresh()
 *	":r !cmd"  and  "!cmd"  to filter text through an external command
 *	A true "undo" facility
 *	An "ex" line oriented mode- maybe using "cmdedit"
 */

//----  Feature --------------  Bytes to immplement
#ifdef STANDALONE
#define vi_main			main
#define CONFIG_FEATURE_VI_COLON	// 4288
#define CONFIG_FEATURE_VI_YANKMARK	// 1408
#define CONFIG_FEATURE_VI_SEARCH	// 1088
#define CONFIG_FEATURE_VI_USE_SIGNALS	// 1056
#define CONFIG_FEATURE_VI_DOT_CMD	//  576
#define CONFIG_FEATURE_VI_READONLY	//  128
#define CONFIG_FEATURE_VI_SETOPTS	//  576
#define CONFIG_FEATURE_VI_SET	//  224
#define CONFIG_FEATURE_VI_WIN_RESIZE	//  256  WIN_RESIZE
// To test editor using CRASHME:
//    vi -C filename
// To stop testing, wait until all to text[] is deleted, or
//    Ctrl-Z and kill -9 %1
// while in the editor Ctrl-T will toggle the crashme function on and off.
//#define CONFIG_FEATURE_VI_CRASHME		// randomly pick commands to execute
#endif							/* STANDALONE */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <setjmp.h>
#include <regex.h>
#include <ctype.h>
#include <assert.h>
#include <errno.h>
#include <stdarg.h>
#ifndef STANDALONE
#include "busybox.h"
#endif							/* STANDALONE */

#ifdef CONFIG_LOCALE_SUPPORT
#define Isprint(c) isprint((c))
#else
#define Isprint(c) ( (c) >= ' ' && (c) != 127 && (c) != ((unsigned char)'\233') )
#endif

#ifndef TRUE
#define TRUE			((int)1)
#define FALSE			((int)0)
#endif							/* TRUE */
#define MAX_SCR_COLS		BUFSIZ

// Misc. non-Ascii keys that report an escape sequence
#define VI_K_UP			128	// cursor key Up
#define VI_K_DOWN		129	// cursor key Down
#define VI_K_RIGHT		130	// Cursor Key Right
#define VI_K_LEFT		131	// cursor key Left
#define VI_K_HOME		132	// Cursor Key Home
#define VI_K_END		133	// Cursor Key End
#define VI_K_INSERT		134	// Cursor Key Insert
#define VI_K_PAGEUP		135	// Cursor Key Page Up
#define VI_K_PAGEDOWN		136	// Cursor Key Page Down
#define VI_K_FUN1		137	// Function Key F1
#define VI_K_FUN2		138	// Function Key F2
#define VI_K_FUN3		139	// Function Key F3
#define VI_K_FUN4		140	// Function Key F4
#define VI_K_FUN5		141	// Function Key F5
#define VI_K_FUN6		142	// Function Key F6
#define VI_K_FUN7		143	// Function Key F7
#define VI_K_FUN8		144	// Function Key F8
#define VI_K_FUN9		145	// Function Key F9
#define VI_K_FUN10		146	// Function Key F10
#define VI_K_FUN11		147	// Function Key F11
#define VI_K_FUN12		148	// Function Key F12

/* vt102 typical ESC sequence */
/* terminal standout start/normal ESC sequence */
static const char SOs[] = "\033[7m";
static const char SOn[] = "\033[0m";
/* terminal bell sequence */
static const char bell[] = "\007";
/* Clear-end-of-line and Clear-end-of-screen ESC sequence */
static const char Ceol[] = "\033[0K";
static const char Ceos [] = "\033[0J";
/* Cursor motion arbitrary destination ESC sequence */
static const char CMrc[] = "\033[%d;%dH";
/* Cursor motion up and down ESC sequence */
static const char CMup[] = "\033[A";
static const char CMdown[] = "\n";


static const int YANKONLY = FALSE;
static const int YANKDEL = TRUE;
static const int FORWARD = 1;	// code depends on "1"  for array index
static const int BACK = -1;	// code depends on "-1" for array index
static const int LIMITED = 0;	// how much of text[] in char_search
static const int FULL = 1;	// how much of text[] in char_search

static const int S_BEFORE_WS = 1;	// used in skip_thing() for moving "dot"
static const int S_TO_WS = 2;		// used in skip_thing() for moving "dot"
static const int S_OVER_WS = 3;		// used in skip_thing() for moving "dot"
static const int S_END_PUNCT = 4;	// used in skip_thing() for moving "dot"
static const int S_END_ALNUM = 5;	// used in skip_thing() for moving "dot"

typedef unsigned char Byte;

static int vi_setops;
#define VI_AUTOINDENT 1
#define VI_SHOWMATCH  2
#define VI_IGNORECASE 4
#define VI_ERR_METHOD 8
#define autoindent (vi_setops & VI_AUTOINDENT)
#define showmatch  (vi_setops & VI_SHOWMATCH )
#define ignorecase (vi_setops & VI_IGNORECASE)
/* indicate error with beep or flash */
#define err_method (vi_setops & VI_ERR_METHOD)


static int editing;		// >0 while we are editing a file
static int cmd_mode;		// 0=command  1=insert
static int file_modified;	// buffer contents changed
static int fn_start;		// index of first cmd line file name
static int save_argc;		// how many file names on cmd line
static int cmdcnt;		// repetition count
static fd_set rfds;		// use select() for small sleeps
static struct timeval tv;	// use select() for small sleeps
static int rows, columns;	// the terminal screen is this size
static int crow, ccol, offset;	// cursor is on Crow x Ccol with Horz Ofset
static Byte *status_buffer;	// mesages to the user
static Byte *cfn;		// previous, current, and next file name
static Byte *text, *end, *textend;	// pointers to the user data in memory
static Byte *screen;		// pointer to the virtual screen buffer
static int screensize;		//            and its size
static Byte *screenbegin;	// index into text[], of top line on the screen
static Byte *dot;		// where all the action takes place
static int tabstop;
static struct termios term_orig, term_vi;	// remember what the cooked mode was
static Byte erase_char;         // the users erase character
static Byte last_input_char;    // last char read from user
static Byte last_forward_char;  // last char searched for with 'f'

#ifdef CONFIG_FEATURE_VI_OPTIMIZE_CURSOR
static int last_row;		// where the cursor was last moved to
#endif							/* CONFIG_FEATURE_VI_OPTIMIZE_CURSOR */
#ifdef CONFIG_FEATURE_VI_USE_SIGNALS
static jmp_buf restart;		// catch_sig()
#endif							/* CONFIG_FEATURE_VI_USE_SIGNALS */
#if defined(CONFIG_FEATURE_VI_USE_SIGNALS) || defined(CONFIG_FEATURE_VI_CRASHME)
static int my_pid;
#endif
#ifdef CONFIG_FEATURE_VI_DOT_CMD
static int adding2q;		// are we currently adding user input to q
static Byte *last_modifying_cmd;	// last modifying cmd for "."
static Byte *ioq, *ioq_start;	// pointer to string for get_one_char to "read"
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
#if	defined(CONFIG_FEATURE_VI_DOT_CMD) || defined(CONFIG_FEATURE_VI_YANKMARK)
static Byte *modifying_cmds;	// cmds that modify text[]
#endif							/* CONFIG_FEATURE_VI_DOT_CMD || CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_READONLY
static int vi_readonly, readonly;
#endif							/* CONFIG_FEATURE_VI_READONLY */
#ifdef CONFIG_FEATURE_VI_YANKMARK
static Byte *reg[28];		// named register a-z, "D", and "U" 0-25,26,27
static int YDreg, Ureg;		// default delete register and orig line for "U"
static Byte *mark[28];		// user marks points somewhere in text[]-  a-z and previous context ''
static Byte *context_start, *context_end;
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_SEARCH
static Byte *last_search_pattern;	// last pattern from a '/' or '?' search
#endif							/* CONFIG_FEATURE_VI_SEARCH */


static void edit_file(Byte *);	// edit one file
static void do_cmd(Byte);	// execute a command
static void sync_cursor(Byte *, int *, int *);	// synchronize the screen cursor to dot
static Byte *begin_line(Byte *);	// return pointer to cur line B-o-l
static Byte *end_line(Byte *);	// return pointer to cur line E-o-l
static Byte *prev_line(Byte *);	// return pointer to prev line B-o-l
static Byte *next_line(Byte *);	// return pointer to next line B-o-l
static Byte *end_screen(void);	// get pointer to last char on screen
static int count_lines(Byte *, Byte *);	// count line from start to stop
static Byte *find_line(int);	// find begining of line #li
static Byte *move_to_col(Byte *, int);	// move "p" to column l
static int isblnk(Byte);	// is the char a blank or tab
static void dot_left(void);	// move dot left- dont leave line
static void dot_right(void);	// move dot right- dont leave line
static void dot_begin(void);	// move dot to B-o-l
static void dot_end(void);	// move dot to E-o-l
static void dot_next(void);	// move dot to next line B-o-l
static void dot_prev(void);	// move dot to prev line B-o-l
static void dot_scroll(int, int);	// move the screen up or down
static void dot_skip_over_ws(void);	// move dot pat WS
static void dot_delete(void);	// delete the char at 'dot'
static Byte *bound_dot(Byte *);	// make sure  text[0] <= P < "end"
static Byte *new_screen(int, int);	// malloc virtual screen memory
static Byte *new_text(int);	// malloc memory for text[] buffer
static Byte *char_insert(Byte *, Byte);	// insert the char c at 'p'
static Byte *stupid_insert(Byte *, Byte);	// stupidly insert the char c at 'p'
static Byte find_range(Byte **, Byte **, Byte);	// return pointers for an object
static int st_test(Byte *, int, int, Byte *);	// helper for skip_thing()
static Byte *skip_thing(Byte *, int, int, int);	// skip some object
static Byte *find_pair(Byte *, Byte);	// find matching pair ()  []  {}
static Byte *text_hole_delete(Byte *, Byte *);	// at "p", delete a 'size' byte hole
static Byte *text_hole_make(Byte *, int);	// at "p", make a 'size' byte hole
static Byte *yank_delete(Byte *, Byte *, int, int);	// yank text[] into register then delete
static void show_help(void);	// display some help info
static void rawmode(void);	// set "raw" mode on tty
static void cookmode(void);	// return to "cooked" mode on tty
static int mysleep(int);	// sleep for 'h' 1/100 seconds
static Byte readit(void);	// read (maybe cursor) key from stdin
static Byte get_one_char(void);	// read 1 char from stdin
static int file_size(const Byte *);   // what is the byte size of "fn"
static int file_insert(Byte *, Byte *, int);
static int file_write(Byte *, Byte *, Byte *);
static void place_cursor(int, int, int);
static void screen_erase(void);
static void clear_to_eol(void);
static void clear_to_eos(void);
static void standout_start(void);	// send "start reverse video" sequence
static void standout_end(void);	// send "end reverse video" sequence
static void flash(int);		// flash the terminal screen
static void show_status_line(void);	// put a message on the bottom line
static void psb(const char *, ...);     // Print Status Buf
static void psbs(const char *, ...);    // Print Status Buf in standout mode
static void ni(Byte *);		// display messages
static void edit_status(void);	// show file status on status line
static void redraw(int);	// force a full screen refresh
static void format_line(Byte*, Byte*, int);
static void refresh(int);	// update the terminal from screen[]

static void Indicate_Error(void);       // use flash or beep to indicate error
#define indicate_error(c) Indicate_Error()

#ifdef CONFIG_FEATURE_VI_SEARCH
static Byte *char_search(Byte *, Byte *, int, int);	// search for pattern starting at p
static int mycmp(Byte *, Byte *, int);	// string cmp based in "ignorecase"
#endif							/* CONFIG_FEATURE_VI_SEARCH */
#ifdef CONFIG_FEATURE_VI_COLON
static void Hit_Return(void);
static Byte *get_one_address(Byte *, int *);	// get colon addr, if present
static Byte *get_address(Byte *, int *, int *);	// get two colon addrs, if present
static void colon(Byte *);	// execute the "colon" mode cmds
#endif							/* CONFIG_FEATURE_VI_COLON */
#ifdef CONFIG_FEATURE_VI_USE_SIGNALS
static void winch_sig(int);	// catch window size changes
static void suspend_sig(int);	// catch ctrl-Z
static void catch_sig(int);     // catch ctrl-C and alarm time-outs
static void core_sig(int);	// catch a core dump signal
#endif							/* CONFIG_FEATURE_VI_USE_SIGNALS */
#ifdef CONFIG_FEATURE_VI_DOT_CMD
static void start_new_cmd_q(Byte);	// new queue for command
static void end_cmd_q(void);	// stop saving input chars
#else							/* CONFIG_FEATURE_VI_DOT_CMD */
#define end_cmd_q()
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
#ifdef CONFIG_FEATURE_VI_WIN_RESIZE
static void window_size_get(int);	// find out what size the window is
#endif							/* CONFIG_FEATURE_VI_WIN_RESIZE */
#ifdef CONFIG_FEATURE_VI_SETOPTS
static void showmatching(Byte *);	// show the matching pair ()  []  {}
#endif							/* CONFIG_FEATURE_VI_SETOPTS */
#if defined(CONFIG_FEATURE_VI_YANKMARK) || defined(CONFIG_FEATURE_VI_COLON) || defined(CONFIG_FEATURE_VI_CRASHME)
static Byte *string_insert(Byte *, Byte *);	// insert the string at 'p'
#endif							/* CONFIG_FEATURE_VI_YANKMARK || CONFIG_FEATURE_VI_COLON || CONFIG_FEATURE_VI_CRASHME */
#ifdef CONFIG_FEATURE_VI_YANKMARK
static Byte *text_yank(Byte *, Byte *, int);	// save copy of "p" into a register
static Byte what_reg(void);		// what is letter of current YDreg
static void check_context(Byte);	// remember context for '' command
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_CRASHME
static void crash_dummy();
static void crash_test();
static int crashme = 0;
#endif							/* CONFIG_FEATURE_VI_CRASHME */


static void write1(const char *out)
{
	fputs(out, stdout);
}

extern int vi_main(int argc, char **argv)
{
	int c;
	RESERVE_CONFIG_BUFFER(STATUS_BUFFER, 200);

#ifdef CONFIG_FEATURE_VI_YANKMARK
	int i;
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#if defined(CONFIG_FEATURE_VI_USE_SIGNALS) || defined(CONFIG_FEATURE_VI_CRASHME)
	my_pid = getpid();
#endif
#ifdef CONFIG_FEATURE_VI_CRASHME
	(void) srand((long) my_pid);
#endif							/* CONFIG_FEATURE_VI_CRASHME */

	status_buffer = STATUS_BUFFER;

#ifdef CONFIG_FEATURE_VI_READONLY
	vi_readonly = readonly = FALSE;
	if (strncmp(argv[0], "view", 4) == 0) {
		readonly = TRUE;
		vi_readonly = TRUE;
	}
#endif							/* CONFIG_FEATURE_VI_READONLY */
	vi_setops = VI_AUTOINDENT | VI_SHOWMATCH | VI_IGNORECASE | VI_ERR_METHOD;
#ifdef CONFIG_FEATURE_VI_YANKMARK
	for (i = 0; i < 28; i++) {
		reg[i] = 0;
	}					// init the yank regs
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#if defined(CONFIG_FEATURE_VI_DOT_CMD) || defined(CONFIG_FEATURE_VI_YANKMARK)
	modifying_cmds = (Byte *) "aAcCdDiIJoOpPrRsxX<>~";	// cmds modifying text[]
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */

	//  1-  process $HOME/.exrc file
	//  2-  process EXINIT variable from environment
	//  3-  process command line args
	while ((c = getopt(argc, argv, "hCR")) != -1) {
		switch (c) {
#ifdef CONFIG_FEATURE_VI_CRASHME
		case 'C':
			crashme = 1;
			break;
#endif							/* CONFIG_FEATURE_VI_CRASHME */
#ifdef CONFIG_FEATURE_VI_READONLY
		case 'R':		// Read-only flag
			readonly = TRUE;
			vi_readonly = TRUE;
			break;
#endif							/* CONFIG_FEATURE_VI_READONLY */
			//case 'r':	// recover flag-  ignore- we don't use tmp file
			//case 'x':	// encryption flag- ignore
			//case 'c':	// execute command first
			//case 'h':	// help -- just use default
		default:
			show_help();
			return 1;
		}
	}

	// The argv array can be used by the ":next"  and ":rewind" commands
	// save optind.
	fn_start = optind;	// remember first file name for :next and :rew
	save_argc = argc;

	//----- This is the main file handling loop --------------
	if (optind >= argc) {
		editing = 1;	// 0= exit,  1= one file,  2= multiple files
		edit_file(0);
	} else {
		for (; optind < argc; optind++) {
			editing = 1;	// 0=exit, 1=one file, 2+ =many files
			free(cfn);
			cfn = (Byte *) bb_xstrdup(argv[optind]);
			edit_file(cfn);
		}
	}
	//-----------------------------------------------------------

	return (0);
}

#ifdef CONFIG_FEATURE_VI_WIN_RESIZE
//----- See what the window size currently is --------------------
static inline void window_size_get(int fd)
{
	get_terminal_width_height(fd, &columns, &rows);
}
#endif							/* CONFIG_FEATURE_VI_WIN_RESIZE */

static void edit_file(Byte * fn)
{
	Byte c;
	int cnt, size, ch;

#ifdef CONFIG_FEATURE_VI_USE_SIGNALS
	int sig;
#endif							/* CONFIG_FEATURE_VI_USE_SIGNALS */
#ifdef CONFIG_FEATURE_VI_YANKMARK
	static Byte *cur_line;
#endif							/* CONFIG_FEATURE_VI_YANKMARK */

	rawmode();
	rows = 24;
	columns = 80;
	ch= -1;
#ifdef CONFIG_FEATURE_VI_WIN_RESIZE
	window_size_get(0);
#endif							/* CONFIG_FEATURE_VI_WIN_RESIZE */
	new_screen(rows, columns);	// get memory for virtual screen

	cnt = file_size(fn);	// file size
	size = 2 * cnt;		// 200% of file size
	new_text(size);		// get a text[] buffer
	screenbegin = dot = end = text;
	if (fn != 0) {
		ch= file_insert(fn, text, cnt);
	}
	if (ch < 1) {
		(void) char_insert(text, '\n');	// start empty buf with dummy line
	}
	file_modified = FALSE;
#ifdef CONFIG_FEATURE_VI_YANKMARK
	YDreg = 26;			// default Yank/Delete reg
	Ureg = 27;			// hold orig line for "U" cmd
	for (cnt = 0; cnt < 28; cnt++) {
		mark[cnt] = 0;
	}					// init the marks
	mark[26] = mark[27] = text;	// init "previous context"
#endif							/* CONFIG_FEATURE_VI_YANKMARK */

	last_forward_char = last_input_char = '\0';
	crow = 0;
	ccol = 0;
	edit_status();

#ifdef CONFIG_FEATURE_VI_USE_SIGNALS
	catch_sig(0);
	core_sig(0);
	signal(SIGWINCH, winch_sig);
	signal(SIGTSTP, suspend_sig);
	sig = setjmp(restart);
	if (sig != 0) {
		const char *msg = "";

		if (sig == SIGWINCH)
			msg = "(window resize)";
		if (sig == SIGHUP)
			msg = "(hangup)";
		if (sig == SIGINT)
			msg = "(interrupt)";
		if (sig == SIGTERM)
			msg = "(terminate)";
		if (sig == SIGBUS)
			msg = "(bus error)";
		if (sig == SIGSEGV)
			msg = "(I tried to touch invalid memory)";
		if (sig == SIGALRM)
			msg = "(alarm)";

		psbs("-- caught signal %d %s--", sig, msg);
		screenbegin = dot = text;
	}
#endif							/* CONFIG_FEATURE_VI_USE_SIGNALS */

	editing = 1;
	cmd_mode = 0;		// 0=command  1=insert  2='R'eplace
	cmdcnt = 0;
	tabstop = 8;
	offset = 0;			// no horizontal offset
	c = '\0';
#ifdef CONFIG_FEATURE_VI_DOT_CMD
	free(last_modifying_cmd);
	free(ioq_start);
	ioq = ioq_start = last_modifying_cmd = 0;
	adding2q = 0;
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
	redraw(FALSE);			// dont force every col re-draw
	show_status_line();
	fflush(stdout);

	//------This is the main Vi cmd handling loop -----------------------
	while (editing > 0) {
#ifdef CONFIG_FEATURE_VI_CRASHME
		if (crashme > 0) {
			if ((end - text) > 1) {
				crash_dummy();	// generate a random command
			} else {
				crashme = 0;
				dot =
					string_insert(text, (Byte *) "\n\n#####  Ran out of text to work on.  #####\n\n");	// insert the string
				refresh(FALSE);
			}
		}
#endif							/* CONFIG_FEATURE_VI_CRASHME */
		last_input_char = c = get_one_char();	// get a cmd from user
#ifdef CONFIG_FEATURE_VI_YANKMARK
		// save a copy of the current line- for the 'U" command
		if (begin_line(dot) != cur_line) {
			cur_line = begin_line(dot);
			text_yank(begin_line(dot), end_line(dot), Ureg);
		}
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_DOT_CMD
		// These are commands that change text[].
		// Remember the input for the "." command
		if (!adding2q && ioq_start == 0
			&& strchr((char *) modifying_cmds, c) != NULL) {
			start_new_cmd_q(c);
		}
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
		do_cmd(c);		// execute the user command
		//
		// poll to see if there is input already waiting. if we are
		// not able to display output fast enough to keep up, skip
		// the display update until we catch up with input.
		if (mysleep(0) == 0) {
			// no input pending- so update output
			refresh(FALSE);
			show_status_line();
		}
#ifdef CONFIG_FEATURE_VI_CRASHME
		if (crashme > 0)
			crash_test();	// test editor variables
#endif							/* CONFIG_FEATURE_VI_CRASHME */
	}
	//-------------------------------------------------------------------

	place_cursor(rows, 0, FALSE);	// go to bottom of screen
	clear_to_eol();		// Erase to end of line
	cookmode();
}

//----- The Colon commands -------------------------------------
#ifdef CONFIG_FEATURE_VI_COLON
static Byte *get_one_address(Byte * p, int *addr)	// get colon addr, if present
{
	int st;
	Byte *q;

#ifdef CONFIG_FEATURE_VI_YANKMARK
	Byte c;
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_SEARCH
	Byte *pat, buf[BUFSIZ];
#endif							/* CONFIG_FEATURE_VI_SEARCH */

	*addr = -1;			// assume no addr
	if (*p == '.') {	// the current line
		p++;
		q = begin_line(dot);
		*addr = count_lines(text, q);
#ifdef CONFIG_FEATURE_VI_YANKMARK
	} else if (*p == '\'') {	// is this a mark addr
		p++;
		c = tolower(*p);
		p++;
		if (c >= 'a' && c <= 'z') {
			// we have a mark
			c = c - 'a';
			q = mark[(int) c];
			if (q != NULL) {	// is mark valid
				*addr = count_lines(text, q);	// count lines
			}
		}
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_SEARCH
	} else if (*p == '/') {	// a search pattern
		q = buf;
		for (p++; *p; p++) {
			if (*p == '/')
				break;
			*q++ = *p;
			*q = '\0';
		}
		pat = (Byte *) bb_xstrdup((char *) buf);	// save copy of pattern
		if (*p == '/')
			p++;
		q = char_search(dot, pat, FORWARD, FULL);
		if (q != NULL) {
			*addr = count_lines(text, q);
		}
		free(pat);
#endif							/* CONFIG_FEATURE_VI_SEARCH */
	} else if (*p == '$') {	// the last line in file
		p++;
		q = begin_line(end - 1);
		*addr = count_lines(text, q);
	} else if (isdigit(*p)) {	// specific line number
		sscanf((char *) p, "%d%n", addr, &st);
		p += st;
	} else {			// I don't reconise this
		// unrecognised address- assume -1
		*addr = -1;
	}
	return (p);
}

static Byte *get_address(Byte *p, int *b, int *e)	// get two colon addrs, if present
{
	//----- get the address' i.e., 1,3   'a,'b  -----
	// get FIRST addr, if present
	while (isblnk(*p))
		p++;				// skip over leading spaces
	if (*p == '%') {			// alias for 1,$
		p++;
		*b = 1;
		*e = count_lines(text, end-1);
		goto ga0;
	}
	p = get_one_address(p, b);
	while (isblnk(*p))
		p++;
	if (*p == ',') {			// is there a address seperator
		p++;
		while (isblnk(*p))
			p++;
		// get SECOND addr, if present
		p = get_one_address(p, e);
	}
ga0:
	while (isblnk(*p))
		p++;				// skip over trailing spaces
	return (p);
}

#ifdef CONFIG_FEATURE_VI_SETOPTS
static void setops(const Byte *args, const char *opname, int flg_no,
			const char *short_opname, int opt)
{
	const char *a = (char *) args + flg_no;
	int l = strlen(opname) - 1; /* opname have + ' ' */

	if (strncasecmp(a, opname, l) == 0 ||
			strncasecmp(a, short_opname, 2) == 0) {
		if(flg_no)
			vi_setops &= ~opt;
		 else
			vi_setops |= opt;
	}
}
#endif

static void colon(Byte * buf)
{
	Byte c, *orig_buf, *buf1, *q, *r;
	Byte *fn, cmd[BUFSIZ], args[BUFSIZ];
	int i, l, li, ch, st, b, e;
	int useforce, forced;
	struct stat st_buf;

	// :3154	// if (-e line 3154) goto it  else stay put
	// :4,33w! foo	// write a portion of buffer to file "foo"
	// :w		// write all of buffer to current file
	// :q		// quit
	// :q!		// quit- dont care about modified file
	// :'a,'z!sort -u   // filter block through sort
	// :'f		// goto mark "f"
	// :'fl		// list literal the mark "f" line
	// :.r bar	// read file "bar" into buffer before dot
	// :/123/,/abc/d    // delete lines from "123" line to "abc" line
	// :/xyz/	// goto the "xyz" line
	// :s/find/replace/ // substitute pattern "find" with "replace"
	// :!<cmd>	// run <cmd> then return
	//
	if (strlen((char *) buf) <= 0)
		goto vc1;
	if (*buf == ':')
		buf++;			// move past the ':'

	forced = useforce = FALSE;
	li = st = ch = i = 0;
	b = e = -1;
	q = text;			// assume 1,$ for the range
	r = end - 1;
	li = count_lines(text, end - 1);
	fn = cfn;			// default to current file
	memset(cmd, '\0', BUFSIZ);	// clear cmd[]
	memset(args, '\0', BUFSIZ);	// clear args[]

	// look for optional address(es)  :.  :1  :1,9   :'q,'a   :%
	buf = get_address(buf, &b, &e);

	// remember orig command line
	orig_buf = buf;

	// get the COMMAND into cmd[]
	buf1 = cmd;
	while (*buf != '\0') {
		if (isspace(*buf))
			break;
		*buf1++ = *buf++;
	}
	// get any ARGuments
	while (isblnk(*buf))
		buf++;
	strcpy((char *) args, (char *) buf);
	buf1 = last_char_is((char *)cmd, '!');
	if (buf1) {
		useforce = TRUE;
		*buf1 = '\0';   // get rid of !
	}
	if (b >= 0) {
		// if there is only one addr, then the addr
		// is the line number of the single line the
		// user wants. So, reset the end
		// pointer to point at end of the "b" line
		q = find_line(b);	// what line is #b
		r = end_line(q);
		li = 1;
	}
	if (e >= 0) {
		// we were given two addrs.  change the
		// end pointer to the addr given by user.
		r = find_line(e);	// what line is #e
		r = end_line(r);
		li = e - b + 1;
	}
	// ------------ now look for the command ------------
	i = strlen((char *) cmd);
	if (i == 0) {		// :123CR goto line #123
		if (b >= 0) {
			dot = find_line(b);	// what line is #b
			dot_skip_over_ws();
		}
	} else if (strncmp((char *) cmd, "!", 1) == 0) {	// run a cmd
		// :!ls   run the <cmd>
		(void) alarm(0);		// wait for input- no alarms
		place_cursor(rows - 1, 0, FALSE);	// go to Status line
		clear_to_eol();			// clear the line
		cookmode();
		system(orig_buf+1);		// run the cmd
		rawmode();
		Hit_Return();			// let user see results
		(void) alarm(3);		// done waiting for input
	} else if (strncmp((char *) cmd, "=", i) == 0) {	// where is the address
		if (b < 0) {	// no addr given- use defaults
			b = e = count_lines(text, dot);
		}
		psb("%d", b);
	} else if (strncasecmp((char *) cmd, "delete", i) == 0) {	// delete lines
		if (b < 0) {	// no addr given- use defaults
			q = begin_line(dot);	// assume .,. for the range
			r = end_line(dot);
		}
		dot = yank_delete(q, r, 1, YANKDEL);	// save, then delete lines
		dot_skip_over_ws();
	} else if (strncasecmp((char *) cmd, "edit", i) == 0) {	// Edit a file
		int sr;
		sr= 0;
		// don't edit, if the current file has been modified
		if (file_modified && ! useforce) {
			psbs("No write since last change (:edit! overrides)");
			goto vc1;
		}
		if (strlen(args) > 0) {
			// the user supplied a file name
			fn= args;
		} else if (cfn != 0 && strlen(cfn) > 0) {
			// no user supplied name- use the current filename
			fn= cfn;
			goto vc5;
		} else {
			// no user file name, no current name- punt
			psbs("No current filename");
			goto vc1;
		}

		// see if file exists- if not, its just a new file request
		if ((sr=stat((char*)fn, &st_buf)) < 0) {
			// This is just a request for a new file creation.
			// The file_insert below will fail but we get
			// an empty buffer with a file name.  Then the "write"
			// command can do the create.
		} else {
			if ((st_buf.st_mode & (S_IFREG)) == 0) {
				// This is not a regular file
				psbs("\"%s\" is not a regular file", fn);
				goto vc1;
			}
			if ((st_buf.st_mode & (S_IRUSR | S_IRGRP | S_IROTH)) == 0) {
				// dont have any read permissions
				psbs("\"%s\" is not readable", fn);
				goto vc1;
			}
		}

		// There is a read-able regular file
		// make this the current file
		q = (Byte *) bb_xstrdup((char *) fn);	// save the cfn
		free(cfn);		// free the old name
		cfn = q;			// remember new cfn

	  vc5:
		// delete all the contents of text[]
		new_text(2 * file_size(fn));
		screenbegin = dot = end = text;

		// insert new file
		ch = file_insert(fn, text, file_size(fn));

		if (ch < 1) {
			// start empty buf with dummy line
			(void) char_insert(text, '\n');
			ch= 1;
		}
		file_modified = FALSE;
#ifdef CONFIG_FEATURE_VI_YANKMARK
		if (Ureg >= 0 && Ureg < 28 && reg[Ureg] != 0) {
			free(reg[Ureg]);	//   free orig line reg- for 'U'
			reg[Ureg]= 0;
		}
		if (YDreg >= 0 && YDreg < 28 && reg[YDreg] != 0) {
			free(reg[YDreg]);	//   free default yank/delete register
			reg[YDreg]= 0;
		}
		for (li = 0; li < 28; li++) {
			mark[li] = 0;
		}				// init the marks
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
		// how many lines in text[]?
		li = count_lines(text, end - 1);
		psb("\"%s\"%s"
#ifdef CONFIG_FEATURE_VI_READONLY
			"%s"
#endif							/* CONFIG_FEATURE_VI_READONLY */
			" %dL, %dC", cfn,
			(sr < 0 ? " [New file]" : ""),
#ifdef CONFIG_FEATURE_VI_READONLY
			((vi_readonly || readonly) ? " [Read only]" : ""),
#endif							/* CONFIG_FEATURE_VI_READONLY */
			li, ch);
	} else if (strncasecmp((char *) cmd, "file", i) == 0) {	// what File is this
		if (b != -1 || e != -1) {
			ni((Byte *) "No address allowed on this command");
			goto vc1;
		}
		if (strlen((char *) args) > 0) {
			// user wants a new filename
			free(cfn);
			cfn = (Byte *) bb_xstrdup((char *) args);
		} else {
			// user wants file status info
			edit_status();
		}
	} else if (strncasecmp((char *) cmd, "features", i) == 0) {	// what features are available
		// print out values of all features
		place_cursor(rows - 1, 0, FALSE);	// go to Status line, bottom of screen
		clear_to_eol();	// clear the line
		cookmode();
		show_help();
		rawmode();
		Hit_Return();
	} else if (strncasecmp((char *) cmd, "list", i) == 0) {	// literal print line
		if (b < 0) {	// no addr given- use defaults
			q = begin_line(dot);	// assume .,. for the range
			r = end_line(dot);
		}
		place_cursor(rows - 1, 0, FALSE);	// go to Status line, bottom of screen
		clear_to_eol();	// clear the line
		puts("\r");
		for (; q <= r; q++) {
			int c_is_no_print;

			c = *q;
			c_is_no_print = c > 127 && !Isprint(c);
			if (c_is_no_print) {
				c = '.';
				standout_start();
				}
			if (c == '\n') {
				write1("$\r");
			} else if (c < ' ' || c == 127) {
				putchar('^');
				if(c == 127)
					c = '?';
				 else
				c += '@';
			}
			putchar(c);
			if (c_is_no_print)
				standout_end();
		}
#ifdef CONFIG_FEATURE_VI_SET
	  vc2:
#endif							/* CONFIG_FEATURE_VI_SET */
		Hit_Return();
	} else if ((strncasecmp((char *) cmd, "quit", i) == 0) ||	// Quit
			   (strncasecmp((char *) cmd, "next", i) == 0)) {	// edit next file
		if (useforce) {
			// force end of argv list
			if (*cmd == 'q') {
				optind = save_argc;
			}
			editing = 0;
			goto vc1;
		}
		// don't exit if the file been modified
		if (file_modified) {
			psbs("No write since last change (:%s! overrides)",
				 (*cmd == 'q' ? "quit" : "next"));
			goto vc1;
		}
		// are there other file to edit
		if (*cmd == 'q' && optind < save_argc - 1) {
			psbs("%d more file to edit", (save_argc - optind - 1));
			goto vc1;
		}
		if (*cmd == 'n' && optind >= save_argc - 1) {
			psbs("No more files to edit");
			goto vc1;
		}
		editing = 0;
	} else if (strncasecmp((char *) cmd, "read", i) == 0) {	// read file into text[]
		fn = args;
		if (strlen((char *) fn) <= 0) {
			psbs("No filename given");
			goto vc1;
		}
		if (b < 0) {	// no addr given- use defaults
			q = begin_line(dot);	// assume "dot"
		}
		// read after current line- unless user said ":0r foo"
		if (b != 0)
			q = next_line(q);
#ifdef CONFIG_FEATURE_VI_READONLY
		l= readonly;			// remember current files' status
#endif
		ch = file_insert(fn, q, file_size(fn));
#ifdef CONFIG_FEATURE_VI_READONLY
		readonly= l;
#endif
		if (ch < 0)
			goto vc1;	// nothing was inserted
		// how many lines in text[]?
		li = count_lines(q, q + ch - 1);
		psb("\"%s\""
#ifdef CONFIG_FEATURE_VI_READONLY
			"%s"
#endif							/* CONFIG_FEATURE_VI_READONLY */
			" %dL, %dC", fn,
#ifdef CONFIG_FEATURE_VI_READONLY
			((vi_readonly || readonly) ? " [Read only]" : ""),
#endif							/* CONFIG_FEATURE_VI_READONLY */
			li, ch);
		if (ch > 0) {
			// if the insert is before "dot" then we need to update
			if (q <= dot)
				dot += ch;
			file_modified = TRUE;
		}
	} else if (strncasecmp((char *) cmd, "rewind", i) == 0) {	// rewind cmd line args
		if (file_modified && ! useforce) {
			psbs("No write since last change (:rewind! overrides)");
		} else {
			// reset the filenames to edit
			optind = fn_start - 1;
			editing = 0;
		}
#ifdef CONFIG_FEATURE_VI_SET
	} else if (strncasecmp((char *) cmd, "set", i) == 0) {	// set or clear features
		i = 0;			// offset into args
		if (strlen((char *) args) == 0) {
			// print out values of all options
			place_cursor(rows - 1, 0, FALSE);	// go to Status line, bottom of screen
			clear_to_eol();	// clear the line
			printf("----------------------------------------\r\n");
#ifdef CONFIG_FEATURE_VI_SETOPTS
			if (!autoindent)
				printf("no");
			printf("autoindent ");
			if (!err_method)
				printf("no");
			printf("flash ");
			if (!ignorecase)
				printf("no");
			printf("ignorecase ");
			if (!showmatch)
				printf("no");
			printf("showmatch ");
			printf("tabstop=%d ", tabstop);
#endif							/* CONFIG_FEATURE_VI_SETOPTS */
			printf("\r\n");
			goto vc2;
		}
		if (strncasecmp((char *) args, "no", 2) == 0)
			i = 2;		// ":set noautoindent"
#ifdef CONFIG_FEATURE_VI_SETOPTS
		setops(args, "autoindent ", i, "ai", VI_AUTOINDENT);
		setops(args, "flash ", i, "fl", VI_ERR_METHOD);
		setops(args, "ignorecase ", i, "ic", VI_IGNORECASE);
		setops(args, "showmatch ", i, "ic", VI_SHOWMATCH);
		if (strncasecmp((char *) args + i, "tabstop=%d ", 7) == 0) {
			sscanf(strchr((char *) args + i, '='), "=%d", &ch);
			if (ch > 0 && ch < columns - 1)
				tabstop = ch;
		}
#endif							/* CONFIG_FEATURE_VI_SETOPTS */
#endif							/* CONFIG_FEATURE_VI_SET */
#ifdef CONFIG_FEATURE_VI_SEARCH
	} else if (strncasecmp((char *) cmd, "s", 1) == 0) {	// substitute a pattern with a replacement pattern
		Byte *ls, *F, *R;
		int gflag;

		// F points to the "find" pattern
		// R points to the "replace" pattern
		// replace the cmd line delimiters "/" with NULLs
		gflag = 0;		// global replace flag
		c = orig_buf[1];	// what is the delimiter
		F = orig_buf + 2;	// start of "find"
		R = (Byte *) strchr((char *) F, c);	// middle delimiter
		if (!R) goto colon_s_fail;
		*R++ = '\0';	// terminate "find"
		buf1 = (Byte *) strchr((char *) R, c);
		if (!buf1) goto colon_s_fail;
		*buf1++ = '\0';	// terminate "replace"
		if (*buf1 == 'g') {	// :s/foo/bar/g
			buf1++;
			gflag++;	// turn on gflag
		}
		q = begin_line(q);
		if (b < 0) {	// maybe :s/foo/bar/
			q = begin_line(dot);	// start with cur line
			b = count_lines(text, q);	// cur line number
		}
		if (e < 0)
			e = b;		// maybe :.s/foo/bar/
		for (i = b; i <= e; i++) {	// so, :20,23 s \0 find \0 replace \0
			ls = q;		// orig line start
		  vc4:
			buf1 = char_search(q, F, FORWARD, LIMITED);	// search cur line only for "find"
			if (buf1 != NULL) {
				// we found the "find" pattern- delete it
				(void) text_hole_delete(buf1, buf1 + strlen((char *) F) - 1);
				// inset the "replace" patern
				(void) string_insert(buf1, R);	// insert the string
				// check for "global"  :s/foo/bar/g
				if (gflag == 1) {
					if ((buf1 + strlen((char *) R)) < end_line(ls)) {
						q = buf1 + strlen((char *) R);
						goto vc4;	// don't let q move past cur line
					}
				}
			}
			q = next_line(ls);
		}
#endif							/* CONFIG_FEATURE_VI_SEARCH */
	} else if (strncasecmp((char *) cmd, "version", i) == 0) {	// show software version
		psb("%s", vi_Version);
	} else if ((strncasecmp((char *) cmd, "write", i) == 0) ||	// write text to file
			   (strncasecmp((char *) cmd, "wq", i) == 0) ||
			   (strncasecmp((char *) cmd, "x", i) == 0)) {
		// is there a file name to write to?
		if (strlen((char *) args) > 0) {
			fn = args;
		}
#ifdef CONFIG_FEATURE_VI_READONLY
		if ((vi_readonly || readonly) && ! useforce) {
			psbs("\"%s\" File is read only", fn);
			goto vc3;
		}
#endif							/* CONFIG_FEATURE_VI_READONLY */
		// how many lines in text[]?
		li = count_lines(q, r);
		ch = r - q + 1;
		// see if file exists- if not, its just a new file request
		if (useforce) {
			// if "fn" is not write-able, chmod u+w
			// sprintf(syscmd, "chmod u+w %s", fn);
			// system(syscmd);
			forced = TRUE;
		}
		l = file_write(fn, q, r);
		if (useforce && forced) {
			// chmod u-w
			// sprintf(syscmd, "chmod u-w %s", fn);
			// system(syscmd);
			forced = FALSE;
		}
		psb("\"%s\" %dL, %dC", fn, li, l);
		if (q == text && r == end - 1 && l == ch)
			file_modified = FALSE;
		if ((cmd[0] == 'x' || cmd[1] == 'q') && l == ch) {
			editing = 0;
		}
#ifdef CONFIG_FEATURE_VI_READONLY
	  vc3:;
#endif							/* CONFIG_FEATURE_VI_READONLY */
#ifdef CONFIG_FEATURE_VI_YANKMARK
	} else if (strncasecmp((char *) cmd, "yank", i) == 0) {	// yank lines
		if (b < 0) {	// no addr given- use defaults
			q = begin_line(dot);	// assume .,. for the range
			r = end_line(dot);
		}
		text_yank(q, r, YDreg);
		li = count_lines(q, r);
		psb("Yank %d lines (%d chars) into [%c]",
			li, strlen((char *) reg[YDreg]), what_reg());
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
	} else {
		// cmd unknown
		ni((Byte *) cmd);
	}
  vc1:
	dot = bound_dot(dot);	// make sure "dot" is valid
	return;
#ifdef CONFIG_FEATURE_VI_SEARCH
colon_s_fail:
	psb(":s expression missing delimiters");
#endif
}

static void Hit_Return(void)
{
	char c;

	standout_start();	// start reverse video
	write1("[Hit return to continue]");
	standout_end();		// end reverse video
	while ((c = get_one_char()) != '\n' && c != '\r')	/*do nothing */
		;
	redraw(TRUE);		// force redraw all
}
#endif							/* CONFIG_FEATURE_VI_COLON */

//----- Synchronize the cursor to Dot --------------------------
static void sync_cursor(Byte * d, int *row, int *col)
{
	Byte *beg_cur, *end_cur;	// begin and end of "d" line
	Byte *beg_scr, *end_scr;	// begin and end of screen
	Byte *tp;
	int cnt, ro, co;

	beg_cur = begin_line(d);	// first char of cur line
	end_cur = end_line(d);	// last char of cur line

	beg_scr = end_scr = screenbegin;	// first char of screen
	end_scr = end_screen();	// last char of screen

	if (beg_cur < screenbegin) {
		// "d" is before  top line on screen
		// how many lines do we have to move
		cnt = count_lines(beg_cur, screenbegin);
	  sc1:
		screenbegin = beg_cur;
		if (cnt > (rows - 1) / 2) {
			// we moved too many lines. put "dot" in middle of screen
			for (cnt = 0; cnt < (rows - 1) / 2; cnt++) {
				screenbegin = prev_line(screenbegin);
			}
		}
	} else if (beg_cur > end_scr) {
		// "d" is after bottom line on screen
		// how many lines do we have to move
		cnt = count_lines(end_scr, beg_cur);
		if (cnt > (rows - 1) / 2)
			goto sc1;	// too many lines
		for (ro = 0; ro < cnt - 1; ro++) {
			// move screen begin the same amount
			screenbegin = next_line(screenbegin);
			// now, move the end of screen
			end_scr = next_line(end_scr);
			end_scr = end_line(end_scr);
		}
	}
	// "d" is on screen- find out which row
	tp = screenbegin;
	for (ro = 0; ro < rows - 1; ro++) {	// drive "ro" to correct row
		if (tp == beg_cur)
			break;
		tp = next_line(tp);
	}

	// find out what col "d" is on
	co = 0;
	do {				// drive "co" to correct column
		if (*tp == '\n' || *tp == '\0')
			break;
		if (*tp == '\t') {
			//         7       - (co %    8  )
			co += ((tabstop - 1) - (co % tabstop));
		} else if (*tp < ' ' || *tp == 127) {
			co++;		// display as ^X, use 2 columns
		}
	} while (tp++ < d && ++co);

	// "co" is the column where "dot" is.
	// The screen has "columns" columns.
	// The currently displayed columns are  0+offset -- columns+ofset
	// |-------------------------------------------------------------|
	//               ^ ^                                ^
	//        offset | |------- columns ----------------|
	//
	// If "co" is already in this range then we do not have to adjust offset
	//      but, we do have to subtract the "offset" bias from "co".
	// If "co" is outside this range then we have to change "offset".
	// If the first char of a line is a tab the cursor will try to stay
	//  in column 7, but we have to set offset to 0.

	if (co < 0 + offset) {
		offset = co;
	}
	if (co >= columns + offset) {
		offset = co - columns + 1;
	}
	// if the first char of the line is a tab, and "dot" is sitting on it
	//  force offset to 0.
	if (d == beg_cur && *d == '\t') {
		offset = 0;
	}
	co -= offset;

	*row = ro;
	*col = co;
}

//----- Text Movement Routines ---------------------------------
static Byte *begin_line(Byte * p) // return pointer to first char cur line
{
	while (p > text && p[-1] != '\n')
		p--;			// go to cur line B-o-l
	return (p);
}

static Byte *end_line(Byte * p) // return pointer to NL of cur line line
{
	while (p < end - 1 && *p != '\n')
		p++;			// go to cur line E-o-l
	return (p);
}

static inline Byte *dollar_line(Byte * p) // return pointer to just before NL line
{
	while (p < end - 1 && *p != '\n')
		p++;			// go to cur line E-o-l
	// Try to stay off of the Newline
	if (*p == '\n' && (p - begin_line(p)) > 0)
		p--;
	return (p);
}

static Byte *prev_line(Byte * p) // return pointer first char prev line
{
	p = begin_line(p);	// goto begining of cur line
	if (p[-1] == '\n' && p > text)
		p--;			// step to prev line
	p = begin_line(p);	// goto begining of prev line
	return (p);
}

static Byte *next_line(Byte * p) // return pointer first char next line
{
	p = end_line(p);
	if (*p == '\n' && p < end - 1)
		p++;			// step to next line
	return (p);
}

//----- Text Information Routines ------------------------------
static Byte *end_screen(void)
{
	Byte *q;
	int cnt;

	// find new bottom line
	q = screenbegin;
	for (cnt = 0; cnt < rows - 2; cnt++)
		q = next_line(q);
	q = end_line(q);
	return (q);
}

static int count_lines(Byte * start, Byte * stop) // count line from start to stop
{
	Byte *q;
	int cnt;

	if (stop < start) {	// start and stop are backwards- reverse them
		q = start;
		start = stop;
		stop = q;
	}
	cnt = 0;
	stop = end_line(stop);	// get to end of this line
	for (q = start; q <= stop && q <= end - 1; q++) {
		if (*q == '\n')
			cnt++;
	}
	return (cnt);
}

static Byte *find_line(int li)	// find begining of line #li
{
	Byte *q;

	for (q = text; li > 1; li--) {
		q = next_line(q);
	}
	return (q);
}

//----- Dot Movement Routines ----------------------------------
static void dot_left(void)
{
	if (dot > text && dot[-1] != '\n')
		dot--;
}

static void dot_right(void)
{
	if (dot < end - 1 && *dot != '\n')
		dot++;
}

static void dot_begin(void)
{
	dot = begin_line(dot);	// return pointer to first char cur line
}

static void dot_end(void)
{
	dot = end_line(dot);	// return pointer to last char cur line
}

static Byte *move_to_col(Byte * p, int l)
{
	int co;

	p = begin_line(p);
	co = 0;
	do {
		if (*p == '\n' || *p == '\0')
			break;
		if (*p == '\t') {
			//         7       - (co %    8  )
			co += ((tabstop - 1) - (co % tabstop));
		} else if (*p < ' ' || *p == 127) {
			co++;		// display as ^X, use 2 columns
		}
	} while (++co <= l && p++ < end);
	return (p);
}

static void dot_next(void)
{
	dot = next_line(dot);
}

static void dot_prev(void)
{
	dot = prev_line(dot);
}

static void dot_scroll(int cnt, int dir)
{
	Byte *q;

	for (; cnt > 0; cnt--) {
		if (dir < 0) {
			// scroll Backwards
			// ctrl-Y  scroll up one line
			screenbegin = prev_line(screenbegin);
		} else {
			// scroll Forwards
			// ctrl-E  scroll down one line
			screenbegin = next_line(screenbegin);
		}
	}
	// make sure "dot" stays on the screen so we dont scroll off
	if (dot < screenbegin)
		dot = screenbegin;
	q = end_screen();	// find new bottom line
	if (dot > q)
		dot = begin_line(q);	// is dot is below bottom line?
	dot_skip_over_ws();
}

static void dot_skip_over_ws(void)
{
	// skip WS
	while (isspace(*dot) && *dot != '\n' && dot < end - 1)
		dot++;
}

static void dot_delete(void)	// delete the char at 'dot'
{
	(void) text_hole_delete(dot, dot);
}

static Byte *bound_dot(Byte * p) // make sure  text[0] <= P < "end"
{
	if (p >= end && end > text) {
		p = end - 1;
		indicate_error('1');
	}
	if (p < text) {
		p = text;
		indicate_error('2');
	}
	return (p);
}

//----- Helper Utility Routines --------------------------------

//----------------------------------------------------------------
//----- Char Routines --------------------------------------------
/* Chars that are part of a word-
 *    0123456789_ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
 * Chars that are Not part of a word (stoppers)
 *    !"#$%&'()*+,-./:;<=>?@[\]^`{|}~
 * Chars that are WhiteSpace
 *    TAB NEWLINE VT FF RETURN SPACE
 * DO NOT COUNT NEWLINE AS WHITESPACE
 */

static Byte *new_screen(int ro, int co)
{
	int li;

	free(screen);
	screensize = ro * co + 8;
	screen = (Byte *) xmalloc(screensize);
	// initialize the new screen. assume this will be a empty file.
	screen_erase();
	//   non-existant text[] lines start with a tilde (~).
	for (li = 1; li < ro - 1; li++) {
		screen[(li * co) + 0] = '~';
	}
	return (screen);
}

static Byte *new_text(int size)
{
	if (size < 10240)
		size = 10240;	// have a minimum size for new files
	free(text);
	text = (Byte *) xmalloc(size + 8);
	memset(text, '\0', size);	// clear new text[]
	//text += 4;		// leave some room for "oops"
	textend = text + size - 1;
	//textend -= 4;		// leave some root for "oops"
	return (text);
}

#ifdef CONFIG_FEATURE_VI_SEARCH
static int mycmp(Byte * s1, Byte * s2, int len)
{
	int i;

	i = strncmp((char *) s1, (char *) s2, len);
#ifdef CONFIG_FEATURE_VI_SETOPTS
	if (ignorecase) {
		i = strncasecmp((char *) s1, (char *) s2, len);
	}
#endif							/* CONFIG_FEATURE_VI_SETOPTS */
	return (i);
}

static Byte *char_search(Byte * p, Byte * pat, int dir, int range)	// search for pattern starting at p
{
#ifndef REGEX_SEARCH
	Byte *start, *stop;
	int len;

	len = strlen((char *) pat);
	if (dir == FORWARD) {
		stop = end - 1;	// assume range is p - end-1
		if (range == LIMITED)
			stop = next_line(p);	// range is to next line
		for (start = p; start < stop; start++) {
			if (mycmp(start, pat, len) == 0) {
				return (start);
			}
		}
	} else if (dir == BACK) {
		stop = text;	// assume range is text - p
		if (range == LIMITED)
			stop = prev_line(p);	// range is to prev line
		for (start = p - len; start >= stop; start--) {
			if (mycmp(start, pat, len) == 0) {
				return (start);
			}
		}
	}
	// pattern not found
	return (NULL);
#else							/*REGEX_SEARCH */
	char *q;
	struct re_pattern_buffer preg;
	int i;
	int size, range;

	re_syntax_options = RE_SYNTAX_POSIX_EXTENDED;
	preg.translate = 0;
	preg.fastmap = 0;
	preg.buffer = 0;
	preg.allocated = 0;

	// assume a LIMITED forward search
	q = next_line(p);
	q = end_line(q);
	q = end - 1;
	if (dir == BACK) {
		q = prev_line(p);
		q = text;
	}
	// count the number of chars to search over, forward or backward
	size = q - p;
	if (size < 0)
		size = p - q;
	// RANGE could be negative if we are searching backwards
	range = q - p;

	q = (char *) re_compile_pattern(pat, strlen((char *) pat), &preg);
	if (q != 0) {
		// The pattern was not compiled
		psbs("bad search pattern: \"%s\": %s", pat, q);
		i = 0;			// return p if pattern not compiled
		goto cs1;
	}

	q = p;
	if (range < 0) {
		q = p - size;
		if (q < text)
			q = text;
	}
	// search for the compiled pattern, preg, in p[]
	// range < 0-  search backward
	// range > 0-  search forward
	// 0 < start < size
	// re_search() < 0  not found or error
	// re_search() > 0  index of found pattern
	//            struct pattern    char     int    int    int     struct reg
	// re_search (*pattern_buffer,  *string, size,  start, range,  *regs)
	i = re_search(&preg, q, size, 0, range, 0);
	if (i == -1) {
		p = 0;
		i = 0;			// return NULL if pattern not found
	}
  cs1:
	if (dir == FORWARD) {
		p = p + i;
	} else {
		p = p - i;
	}
	return (p);
#endif							/*REGEX_SEARCH */
}
#endif							/* CONFIG_FEATURE_VI_SEARCH */

static Byte *char_insert(Byte * p, Byte c) // insert the char c at 'p'
{
	if (c == 22) {		// Is this an ctrl-V?
		p = stupid_insert(p, '^');	// use ^ to indicate literal next
		p--;			// backup onto ^
		refresh(FALSE);	// show the ^
		c = get_one_char();
		*p = c;
		p++;
		file_modified = TRUE;	// has the file been modified
	} else if (c == 27) {	// Is this an ESC?
		cmd_mode = 0;
		cmdcnt = 0;
		end_cmd_q();	// stop adding to q
		strcpy((char *) status_buffer, " ");	// clear the status buffer
		if ((p[-1] != '\n') && (dot>text)) {
			p--;
		}
	} else if (c == erase_char) {	// Is this a BS
		//     123456789
		if ((p[-1] != '\n') && (dot>text)) {
			p--;
			p = text_hole_delete(p, p);	// shrink buffer 1 char
#ifdef CONFIG_FEATURE_VI_DOT_CMD
			// also rmove char from last_modifying_cmd
			if (last_modifying_cmd != 0 && strlen((char *) last_modifying_cmd) > 0) {
				Byte *q;

				q = last_modifying_cmd;
				q[strlen((char *) q) - 1] = '\0';	// erase BS
				q[strlen((char *) q) - 1] = '\0';	// erase prev char
			}
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
		}
	} else {
		// insert a char into text[]
		Byte *sp;		// "save p"

		if (c == 13)
			c = '\n';	// translate \r to \n
		sp = p;			// remember addr of insert
		p = stupid_insert(p, c);	// insert the char
#ifdef CONFIG_FEATURE_VI_SETOPTS
		if (showmatch && strchr(")]}", *sp) != NULL) {
			showmatching(sp);
		}
		if (autoindent && c == '\n') {	// auto indent the new line
			Byte *q;

			q = prev_line(p);	// use prev line as templet
			for (; isblnk(*q); q++) {
				p = stupid_insert(p, *q);	// insert the char
			}
		}
#endif							/* CONFIG_FEATURE_VI_SETOPTS */
	}
	return (p);
}

static Byte *stupid_insert(Byte * p, Byte c) // stupidly insert the char c at 'p'
{
	p = text_hole_make(p, 1);
	if (p != 0) {
		*p = c;
		file_modified = TRUE;	// has the file been modified
		p++;
	}
	return (p);
}

static Byte find_range(Byte ** start, Byte ** stop, Byte c)
{
	Byte *save_dot, *p, *q;
	int cnt;

	save_dot = dot;
	p = q = dot;

	if (strchr("cdy><", c)) {
		// these cmds operate on whole lines
		p = q = begin_line(p);
		for (cnt = 1; cnt < cmdcnt; cnt++) {
			q = next_line(q);
		}
		q = end_line(q);
	} else if (strchr("^%$0bBeEft", c)) {
		// These cmds operate on char positions
		do_cmd(c);		// execute movement cmd
		q = dot;
	} else if (strchr("wW", c)) {
		do_cmd(c);		// execute movement cmd
 		// if we are at the next word's first char
 		// step back one char
 		// but check the possibilities when it is true
		if (dot > text && ((isspace(dot[-1]) && !isspace(dot[0]))
 				|| (ispunct(dot[-1]) && !ispunct(dot[0]))
 				|| (isalnum(dot[-1]) && !isalnum(dot[0]))))
  			dot--;		// move back off of next word
		if (dot > text && *dot == '\n')
			dot--;		// stay off NL
		q = dot;
	} else if (strchr("H-k{", c)) {
		// these operate on multi-lines backwards
		q = end_line(dot);	// find NL
		do_cmd(c);		// execute movement cmd
		dot_begin();
		p = dot;
	} else if (strchr("L+j}\r\n", c)) {
		// these operate on multi-lines forwards
		p = begin_line(dot);
		do_cmd(c);		// execute movement cmd
		dot_end();		// find NL
		q = dot;
	} else {
		c = 27;			// error- return an ESC char
		//break;
	}
	*start = p;
	*stop = q;
	if (q < p) {
		*start = q;
		*stop = p;
	}
	dot = save_dot;
	return (c);
}

static int st_test(Byte * p, int type, int dir, Byte * tested)
{
	Byte c, c0, ci;
	int test, inc;

	inc = dir;
	c = c0 = p[0];
	ci = p[inc];
	test = 0;

	if (type == S_BEFORE_WS) {
		c = ci;
		test = ((!isspace(c)) || c == '\n');
	}
	if (type == S_TO_WS) {
		c = c0;
		test = ((!isspace(c)) || c == '\n');
	}
	if (type == S_OVER_WS) {
		c = c0;
		test = ((isspace(c)));
	}
	if (type == S_END_PUNCT) {
		c = ci;
		test = ((ispunct(c)));
	}
	if (type == S_END_ALNUM) {
		c = ci;
		test = ((isalnum(c)) || c == '_');
	}
	*tested = c;
	return (test);
}

static Byte *skip_thing(Byte * p, int linecnt, int dir, int type)
{
	Byte c;

	while (st_test(p, type, dir, &c)) {
		// make sure we limit search to correct number of lines
		if (c == '\n' && --linecnt < 1)
			break;
		if (dir >= 0 && p >= end - 1)
			break;
		if (dir < 0 && p <= text)
			break;
		p += dir;		// move to next char
	}
	return (p);
}

// find matching char of pair  ()  []  {}
static Byte *find_pair(Byte * p, Byte c)
{
	Byte match, *q;
	int dir, level;

	match = ')';
	level = 1;
	dir = 1;			// assume forward
	switch (c) {
	case '(':
		match = ')';
		break;
	case '[':
		match = ']';
		break;
	case '{':
		match = '}';
		break;
	case ')':
		match = '(';
		dir = -1;
		break;
	case ']':
		match = '[';
		dir = -1;
		break;
	case '}':
		match = '{';
		dir = -1;
		break;
	}
	for (q = p + dir; text <= q && q < end; q += dir) {
		// look for match, count levels of pairs  (( ))
		if (*q == c)
			level++;	// increase pair levels
		if (*q == match)
			level--;	// reduce pair level
		if (level == 0)
			break;		// found matching pair
	}
	if (level != 0)
		q = NULL;		// indicate no match
	return (q);
}

#ifdef CONFIG_FEATURE_VI_SETOPTS
// show the matching char of a pair,  ()  []  {}
static void showmatching(Byte * p)
{
	Byte *q, *save_dot;

	// we found half of a pair
	q = find_pair(p, *p);	// get loc of matching char
	if (q == NULL) {
		indicate_error('3');	// no matching char
	} else {
		// "q" now points to matching pair
		save_dot = dot;	// remember where we are
		dot = q;		// go to new loc
		refresh(FALSE);	// let the user see it
		(void) mysleep(40);	// give user some time
		dot = save_dot;	// go back to old loc
		refresh(FALSE);
	}
}
#endif							/* CONFIG_FEATURE_VI_SETOPTS */

//  open a hole in text[]
static Byte *text_hole_make(Byte * p, int size)	// at "p", make a 'size' byte hole
{
	Byte *src, *dest;
	int cnt;

	if (size <= 0)
		goto thm0;
	src = p;
	dest = p + size;
	cnt = end - src;	// the rest of buffer
	if (memmove(dest, src, cnt) != dest) {
		psbs("can't create room for new characters");
	}
	memset(p, ' ', size);	// clear new hole
	end = end + size;	// adjust the new END
	file_modified = TRUE;	// has the file been modified
  thm0:
	return (p);
}

//  close a hole in text[]
static Byte *text_hole_delete(Byte * p, Byte * q) // delete "p" thru "q", inclusive
{
	Byte *src, *dest;
	int cnt, hole_size;

	// move forwards, from beginning
	// assume p <= q
	src = q + 1;
	dest = p;
	if (q < p) {		// they are backward- swap them
		src = p + 1;
		dest = q;
	}
	hole_size = q - p + 1;
	cnt = end - src;
	if (src < text || src > end)
		goto thd0;
	if (dest < text || dest >= end)
		goto thd0;
	if (src >= end)
		goto thd_atend;	// just delete the end of the buffer
	if (memmove(dest, src, cnt) != dest) {
		psbs("can't delete the character");
	}
  thd_atend:
	end = end - hole_size;	// adjust the new END
	if (dest >= end)
		dest = end - 1;	// make sure dest in below end-1
	if (end <= text)
		dest = end = text;	// keep pointers valid
	file_modified = TRUE;	// has the file been modified
  thd0:
	return (dest);
}

// copy text into register, then delete text.
// if dist <= 0, do not include, or go past, a NewLine
//
static Byte *yank_delete(Byte * start, Byte * stop, int dist, int yf)
{
	Byte *p;

	// make sure start <= stop
	if (start > stop) {
		// they are backwards, reverse them
		p = start;
		start = stop;
		stop = p;
	}
	if (dist <= 0) {
		// we can not cross NL boundaries
		p = start;
		if (*p == '\n')
			return (p);
		// dont go past a NewLine
		for (; p + 1 <= stop; p++) {
			if (p[1] == '\n') {
				stop = p;	// "stop" just before NewLine
				break;
			}
		}
	}
	p = start;
#ifdef CONFIG_FEATURE_VI_YANKMARK
	text_yank(start, stop, YDreg);
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
	if (yf == YANKDEL) {
		p = text_hole_delete(start, stop);
	}					// delete lines
	return (p);
}

static void show_help(void)
{
	puts("These features are available:"
#ifdef CONFIG_FEATURE_VI_SEARCH
	"\n\tPattern searches with / and ?"
#endif							/* CONFIG_FEATURE_VI_SEARCH */
#ifdef CONFIG_FEATURE_VI_DOT_CMD
	"\n\tLast command repeat with \'.\'"
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
#ifdef CONFIG_FEATURE_VI_YANKMARK
	"\n\tLine marking with  'x"
	"\n\tNamed buffers with  \"x"
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
#ifdef CONFIG_FEATURE_VI_READONLY
	"\n\tReadonly if vi is called as \"view\""
	"\n\tReadonly with -R command line arg"
#endif							/* CONFIG_FEATURE_VI_READONLY */
#ifdef CONFIG_FEATURE_VI_SET
	"\n\tSome colon mode commands with \':\'"
#endif							/* CONFIG_FEATURE_VI_SET */
#ifdef CONFIG_FEATURE_VI_SETOPTS
	"\n\tSettable options with \":set\""
#endif							/* CONFIG_FEATURE_VI_SETOPTS */
#ifdef CONFIG_FEATURE_VI_USE_SIGNALS
	"\n\tSignal catching- ^C"
	"\n\tJob suspend and resume with ^Z"
#endif							/* CONFIG_FEATURE_VI_USE_SIGNALS */
#ifdef CONFIG_FEATURE_VI_WIN_RESIZE
	"\n\tAdapt to window re-sizes"
#endif							/* CONFIG_FEATURE_VI_WIN_RESIZE */
	);
}

static inline void print_literal(Byte * buf, Byte * s) // copy s to buf, convert unprintable
{
	Byte c, b[2];

	b[1] = '\0';
	strcpy((char *) buf, "");	// init buf
	if (strlen((char *) s) <= 0)
		s = (Byte *) "(NULL)";
	for (; *s > '\0'; s++) {
		int c_is_no_print;

		c = *s;
		c_is_no_print = c > 127 && !Isprint(c);
		if (c_is_no_print) {
			strcat((char *) buf, SOn);
			c = '.';
		}
		if (c < ' ' || c == 127) {
			strcat((char *) buf, "^");
			if(c == 127)
				c = '?';
			 else
			c += '@';
		}
		b[0] = c;
		strcat((char *) buf, (char *) b);
		if (c_is_no_print)
			strcat((char *) buf, SOs);
		if (*s == '\n') {
			strcat((char *) buf, "$");
		}
	}
}

#ifdef CONFIG_FEATURE_VI_DOT_CMD
static void start_new_cmd_q(Byte c)
{
	// release old cmd
	free(last_modifying_cmd);
	// get buffer for new cmd
	last_modifying_cmd = (Byte *) xmalloc(BUFSIZ);
	memset(last_modifying_cmd, '\0', BUFSIZ);	// clear new cmd queue
	// if there is a current cmd count put it in the buffer first
	if (cmdcnt > 0)
		sprintf((char *) last_modifying_cmd, "%d", cmdcnt);
	// save char c onto queue
	last_modifying_cmd[strlen((char *) last_modifying_cmd)] = c;
	adding2q = 1;
	return;
}

static void end_cmd_q(void)
{
#ifdef CONFIG_FEATURE_VI_YANKMARK
	YDreg = 26;			// go back to default Yank/Delete reg
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
	adding2q = 0;
	return;
}
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */

#if defined(CONFIG_FEATURE_VI_YANKMARK) || defined(CONFIG_FEATURE_VI_COLON) || defined(CONFIG_FEATURE_VI_CRASHME)
static Byte *string_insert(Byte * p, Byte * s) // insert the string at 'p'
{
	int cnt, i;

	i = strlen((char *) s);
	p = text_hole_make(p, i);
	strncpy((char *) p, (char *) s, i);
	for (cnt = 0; *s != '\0'; s++) {
		if (*s == '\n')
			cnt++;
	}
#ifdef CONFIG_FEATURE_VI_YANKMARK
	psb("Put %d lines (%d chars) from [%c]", cnt, i, what_reg());
#endif							/* CONFIG_FEATURE_VI_YANKMARK */
	return (p);
}
#endif							/* CONFIG_FEATURE_VI_YANKMARK || CONFIG_FEATURE_VI_COLON || CONFIG_FEATURE_VI_CRASHME */

#ifdef CONFIG_FEATURE_VI_YANKMARK
static Byte *text_yank(Byte * p, Byte * q, int dest)	// copy text into a register
{
	Byte *t;
	int cnt;

	if (q < p) {		// they are backwards- reverse them
		t = q;
		q = p;
		p = t;
	}
	cnt = q - p + 1;
	t = reg[dest];
	free(t);		//  if already a yank register, free it
	t = (Byte *) xmalloc(cnt + 1);	// get a new register
	memset(t, '\0', cnt + 1);	// clear new text[]
	strncpy((char *) t, (char *) p, cnt);	// copy text[] into bufer
	reg[dest] = t;
	return (p);
}

static Byte what_reg(void)
{
	Byte c;
	int i;

	i = 0;
	c = 'D';			// default to D-reg
	if (0 <= YDreg && YDreg <= 25)
		c = 'a' + (Byte) YDreg;
	if (YDreg == 26)
		c = 'D';
	if (YDreg == 27)
		c = 'U';
	return (c);
}

static void check_context(Byte cmd)
{
	// A context is defined to be "modifying text"
	// Any modifying command establishes a new context.

	if (dot < context_start || dot > context_end) {
		if (strchr((char *) modifying_cmds, cmd) != NULL) {
			// we are trying to modify text[]- make this the current context
			mark[27] = mark[26];	// move cur to prev
			mark[26] = dot;	// move local to cur
			context_start = prev_line(prev_line(dot));
			context_end = next_line(next_line(dot));
			//loiter= start_loiter= now;
		}
	}
	return;
}

static inline Byte *swap_context(Byte * p) // goto new context for '' command make this the current context
{
	Byte *tmp;

	// the current context is in mark[26]
	// the previous context is in mark[27]
	// only swap context if other context is valid
	if (text <= mark[27] && mark[27] <= end - 1) {
		tmp = mark[27];
		mark[27] = mark[26];
		mark[26] = tmp;
		p = mark[26];	// where we are going- previous context
		context_start = prev_line(prev_line(prev_line(p)));
		context_end = next_line(next_line(next_line(p)));
	}
	return (p);
}
#endif							/* CONFIG_FEATURE_VI_YANKMARK */

static int isblnk(Byte c) // is the char a blank or tab
{
	return (c == ' ' || c == '\t');
}

//----- Set terminal attributes --------------------------------
static void rawmode(void)
{
	tcgetattr(0, &term_orig);
	term_vi = term_orig;
	term_vi.c_lflag &= (~ICANON & ~ECHO);	// leave ISIG ON- allow intr's
	term_vi.c_iflag &= (~IXON & ~ICRNL);
	term_vi.c_oflag &= (~ONLCR);
	term_vi.c_cc[VMIN] = 1;
	term_vi.c_cc[VTIME] = 0;
	erase_char = term_vi.c_cc[VERASE];
	tcsetattr(0, TCSANOW, &term_vi);
}

static void cookmode(void)
{
	fflush(stdout);
	tcsetattr(0, TCSANOW, &term_orig);
}

//----- Come here when we get a window resize signal ---------
#ifdef CONFIG_FEATURE_VI_USE_SIGNALS
static void winch_sig(int sig)
{
	signal(SIGWINCH, winch_sig);
#ifdef CONFIG_FEATURE_VI_WIN_RESIZE
	window_size_get(0);
#endif							/* CONFIG_FEATURE_VI_WIN_RESIZE */
	new_screen(rows, columns);	// get memory for virtual screen
	redraw(TRUE);		// re-draw the screen
}

//----- Come here when we get a continue signal -------------------
static void cont_sig(int sig)
{
	rawmode();			// terminal to "raw"
	*status_buffer = '\0';	// clear the status buffer
	redraw(TRUE);		// re-draw the screen

	signal(SIGTSTP, suspend_sig);
	signal(SIGCONT, SIG_DFL);
	kill(my_pid, SIGCONT);
}

//----- Come here when we get a Suspend signal -------------------
static void suspend_sig(int sig)
{
	place_cursor(rows - 1, 0, FALSE);	// go to bottom of screen
	clear_to_eol();		// Erase to end of line
	cookmode();			// terminal to "cooked"

	signal(SIGCONT, cont_sig);
	signal(SIGTSTP, SIG_DFL);
	kill(my_pid, SIGTSTP);
}

//----- Come here when we get a signal ---------------------------
static void catch_sig(int sig)
{
	signal(SIGHUP, catch_sig);
	signal(SIGINT, catch_sig);
	signal(SIGTERM, catch_sig);
	signal(SIGALRM, catch_sig);
	if(sig)
	longjmp(restart, sig);
}

//----- Come here when we get a core dump signal -----------------
static void core_sig(int sig)
{
	signal(SIGQUIT, core_sig);
	signal(SIGILL, core_sig);
	signal(SIGTRAP, core_sig);
	signal(SIGIOT, core_sig);
	signal(SIGABRT, core_sig);
	signal(SIGFPE, core_sig);
	signal(SIGBUS, core_sig);
	signal(SIGSEGV, core_sig);
#ifdef SIGSYS
	signal(SIGSYS, core_sig);
#endif

	if(sig) {       // signaled
	dot = bound_dot(dot);	// make sure "dot" is valid

	longjmp(restart, sig);
	}
}
#endif							/* CONFIG_FEATURE_VI_USE_SIGNALS */

static int mysleep(int hund)	// sleep for 'h' 1/100 seconds
{
	// Don't hang- Wait 5/100 seconds-  1 Sec= 1000000
	fflush(stdout);
	FD_ZERO(&rfds);
	FD_SET(0, &rfds);
	tv.tv_sec = 0;
	tv.tv_usec = hund * 10000;
	select(1, &rfds, NULL, NULL, &tv);
	return (FD_ISSET(0, &rfds));
}

static Byte readbuffer[BUFSIZ];
static int readed_for_parse;

//----- IO Routines --------------------------------------------
static Byte readit(void)	// read (maybe cursor) key from stdin
{
	Byte c;
	int n;
	struct esc_cmds {
		const char *seq;
		Byte val;
	};

	static const struct esc_cmds esccmds[] = {
		{"OA", (Byte) VI_K_UP},       // cursor key Up
		{"OB", (Byte) VI_K_DOWN},     // cursor key Down
		{"OC", (Byte) VI_K_RIGHT},    // Cursor Key Right
		{"OD", (Byte) VI_K_LEFT},     // cursor key Left
		{"OH", (Byte) VI_K_HOME},     // Cursor Key Home
		{"OF", (Byte) VI_K_END},      // Cursor Key End
		{"[A", (Byte) VI_K_UP},       // cursor key Up
		{"[B", (Byte) VI_K_DOWN},     // cursor key Down
		{"[C", (Byte) VI_K_RIGHT},    // Cursor Key Right
		{"[D", (Byte) VI_K_LEFT},     // cursor key Left
		{"[H", (Byte) VI_K_HOME},     // Cursor Key Home
		{"[F", (Byte) VI_K_END},      // Cursor Key End
		{"[1~", (Byte) VI_K_HOME},     // Cursor Key Home
		{"[2~", (Byte) VI_K_INSERT},  // Cursor Key Insert
		{"[4~", (Byte) VI_K_END},      // Cursor Key End
		{"[5~", (Byte) VI_K_PAGEUP},  // Cursor Key Page Up
		{"[6~", (Byte) VI_K_PAGEDOWN},        // Cursor Key Page Down
		{"OP", (Byte) VI_K_FUN1},     // Function Key F1
		{"OQ", (Byte) VI_K_FUN2},     // Function Key F2
		{"OR", (Byte) VI_K_FUN3},     // Function Key F3
		{"OS", (Byte) VI_K_FUN4},     // Function Key F4
		{"[15~", (Byte) VI_K_FUN5},   // Function Key F5
		{"[17~", (Byte) VI_K_FUN6},   // Function Key F6
		{"[18~", (Byte) VI_K_FUN7},   // Function Key F7
		{"[19~", (Byte) VI_K_FUN8},   // Function Key F8
		{"[20~", (Byte) VI_K_FUN9},   // Function Key F9
		{"[21~", (Byte) VI_K_FUN10},  // Function Key F10
		{"[23~", (Byte) VI_K_FUN11},  // Function Key F11
		{"[24~", (Byte) VI_K_FUN12},  // Function Key F12
		{"[11~", (Byte) VI_K_FUN1},   // Function Key F1
		{"[12~", (Byte) VI_K_FUN2},   // Function Key F2
		{"[13~", (Byte) VI_K_FUN3},   // Function Key F3
		{"[14~", (Byte) VI_K_FUN4},   // Function Key F4
	};

#define ESCCMDS_COUNT (sizeof(esccmds)/sizeof(struct esc_cmds))

	(void) alarm(0);	// turn alarm OFF while we wait for input
	fflush(stdout);
	n = readed_for_parse;
	// get input from User- are there already input chars in Q?
	if (n <= 0) {
	  ri0:
		// the Q is empty, wait for a typed char
		n = read(0, readbuffer, BUFSIZ - 1);
		if (n < 0) {
			if (errno == EINTR)
				goto ri0;	// interrupted sys call
			if (errno == EBADF)
				editing = 0;
			if (errno == EFAULT)
				editing = 0;
			if (errno == EINVAL)
				editing = 0;
			if (errno == EIO)
				editing = 0;
			errno = 0;
		}
		if(n <= 0)
			return 0;       // error
		if (readbuffer[0] == 27) {
	// This is an ESC char. Is this Esc sequence?
	// Could be bare Esc key. See if there are any
	// more chars to read after the ESC. This would
	// be a Function or Cursor Key sequence.
	FD_ZERO(&rfds);
	FD_SET(0, &rfds);
	tv.tv_sec = 0;
	tv.tv_usec = 50000;	// Wait 5/100 seconds- 1 Sec=1000000

	// keep reading while there are input chars and room in buffer
			while (select(1, &rfds, NULL, NULL, &tv) > 0 && n <= (BUFSIZ - 5)) {
		// read the rest of the ESC string
				int r = read(0, (void *) (readbuffer + n), BUFSIZ - n);
				if (r > 0) {
					n += r;
				}
			}
		}
		readed_for_parse = n;
	}
	c = readbuffer[0];
	if(c == 27 && n > 1) {
	// Maybe cursor or function key?
		const struct esc_cmds *eindex;

		for (eindex = esccmds; eindex < &esccmds[ESCCMDS_COUNT]; eindex++) {
			int cnt = strlen(eindex->seq);

			if(n <= cnt)
				continue;
			if(strncmp(eindex->seq, (char *) readbuffer + 1, cnt))
				continue;
			// is a Cursor key- put derived value back into Q
			c = eindex->val;
			// for squeeze out the ESC sequence
			n = cnt + 1;
			break;
		}
		if(eindex == &esccmds[ESCCMDS_COUNT]) {
			/* defined ESC sequence not found, set only one ESC */
			n = 1;
	}
	} else {
		n = 1;
	}
	// remove key sequence from Q
	readed_for_parse -= n;
	memmove(readbuffer, readbuffer + n, BUFSIZ - n);
	(void) alarm(3);	// we are done waiting for input, turn alarm ON
	return (c);
}

//----- IO Routines --------------------------------------------
static Byte get_one_char()
{
	static Byte c;

#ifdef CONFIG_FEATURE_VI_DOT_CMD
	// ! adding2q  && ioq == 0  read()
	// ! adding2q  && ioq != 0  *ioq
	// adding2q         *last_modifying_cmd= read()
	if (!adding2q) {
		// we are not adding to the q.
		// but, we may be reading from a q
		if (ioq == 0) {
			// there is no current q, read from STDIN
			c = readit();	// get the users input
		} else {
			// there is a queue to get chars from first
			c = *ioq++;
			if (c == '\0') {
				// the end of the q, read from STDIN
				free(ioq_start);
				ioq_start = ioq = 0;
				c = readit();	// get the users input
			}
		}
	} else {
		// adding STDIN chars to q
		c = readit();	// get the users input
		if (last_modifying_cmd != 0) {
			int len = strlen((char *) last_modifying_cmd);
			if (len + 1 >= BUFSIZ) {
				psbs("last_modifying_cmd overrun");
			} else {
				// add new char to q
				last_modifying_cmd[len] = c;
			}
		}
	}
#else							/* CONFIG_FEATURE_VI_DOT_CMD */
	c = readit();		// get the users input
#endif							/* CONFIG_FEATURE_VI_DOT_CMD */
	return (c);			// return the char, where ever it came from
}

static Byte *get_input_line(Byte * prompt) // get input line- use "status line"
{
	Byte buf[BUFSIZ];
	Byte c;
	int i;
	static Byte *obufp = NULL;

	strcpy((char *) buf, (char *) prompt);
	*status_buffer = '\0';	// clear the status buffer
	place_cursor(rows - 1, 0, FALSE);	// go to Status line, bottom of screen
	clear_to_eol();		// clear the line
	write1(prompt);      // write out the :, /, or ? prompt

	for (i = strlen((char *) buf); i < BUFSIZ;) {
		c = get_one_char();	// read user input
		if (c == '\n' || c == '\r' || c == 27)
			break;		// is this end of input
		if (c == erase_char) {	// user wants to erase prev char
			i--;		// backup to prev char
			buf[i] = '\0';	// erase the char
			buf[i + 1] = '\0';	// null terminate buffer
			write1("\b \b");     // erase char on screen
			if (i <= 0) {	// user backs up before b-o-l, exit
				break;
			}
		} else {
			buf[i] = c;	// save char in buffer
			buf[i + 1] = '\0';	// make sure buffer is null terminated
			putchar(c);   // echo the char back to user
			i++;
		}
	}
	refresh(FALSE);
	free(obufp);
	obufp = (Byte *) bb_xstrdup((char *) buf);
	return (obufp);
}

static int file_size(const Byte * fn) // what is the byte size of "fn"
{
	struct stat st_buf;
	int cnt, sr;

	if (fn == 0 || strlen(fn) <= 0)
		return (-1);
	cnt = -1;
	sr = stat((char *) fn, &st_buf);	// see if file exists
	if (sr >= 0) {
		cnt = (int) st_buf.st_size;
	}
	return (cnt);
}

static int file_insert(Byte * fn, Byte * p, int size)
{
	int fd, cnt;

	cnt = -1;
#ifdef CONFIG_FEATURE_VI_READONLY
	readonly = FALSE;
#endif							/* CONFIG_FEATURE_VI_READONLY */
	if (fn == 0 || strlen((char*) fn) <= 0) {
		psbs("No filename given");
		goto fi0;
	}
	if (size == 0) {
		// OK- this is just a no-op
		cnt = 0;
		goto fi0;
	}
	if (size < 0) {
		psbs("Trying to insert a negative number (%d) of characters", size);
		goto fi0;
	}
	if (p < text || p > end) {
		psbs("Trying to insert file outside of memory");
		goto fi0;
	}

	// see if we can open the file
#ifdef CONFIG_FEATURE_VI_READONLY
	if (vi_readonly) goto fi1;		// do not try write-mode
#endif
	fd = open((char *) fn, O_RDWR);			// assume read & write
	if (fd < 0) {
		// could not open for writing- maybe file is read only
#ifdef CONFIG_FEATURE_VI_READONLY
  fi1:
#endif
		fd = open((char *) fn, O_RDONLY);	// try read-only
		if (fd < 0) {
			psbs("\"%s\" %s", fn, "could not open file");
			goto fi0;
		}
#ifdef CONFIG_FEATURE_VI_READONLY
		// got the file- read-only
		readonly = TRUE;
#endif							/* CONFIG_FEATURE_VI_READONLY */
	}
	p = text_hole_make(p, size);
	cnt = read(fd, p, size);
	close(fd);
	if (cnt < 0) {
		cnt = -1;
		p = text_hole_delete(p, p + size - 1);	// un-do buffer insert
		psbs("could not read file \"%s\"", fn);
	} else if (cnt < size) {
		// There was a partial read, shrink unused space text[]
		p = text_hole_delete(p + cnt, p + (size - cnt) - 1);	// un-do buffer insert
		psbs("could not read all of file \"%s\"", fn);
	}
	if (cnt >= size)
		file_modified = TRUE;
  fi0:
	return (cnt);
}

static int file_write(Byte * fn, Byte * first, Byte * last)
{
	int fd, cnt, charcnt;

	if (fn == 0) {
		psbs("No current filename");
		return (-1);
	}
	charcnt = 0;
	// FIXIT- use the correct umask()
	fd = open((char *) fn, (O_WRONLY | O_CREAT | O_TRUNC), 0664);
	if (fd < 0)
		return (-1);
	cnt = last - first + 1;
	charcnt = write(fd, first, cnt);
	if (charcnt == cnt) {
		// good write
		//file_modified= FALSE; // the file has not been modified
	} else {
		charcnt = 0;
	}
	close(fd);
	return (charcnt);
}

//----- Terminal Drawing ---------------------------------------
// The terminal is made up of 'rows' line of 'columns' columns.
// classicly this would be 24 x 80.
//  screen coordinates
//  0,0     ...     0,79
//  1,0     ...     1,79
//  .       ...     .
//  .       ...     .
//  22,0    ...     22,79
//  23,0    ...     23,79   status line
//

//----- Move the cursor to row x col (count from 0, not 1) -------
static void place_cursor(int row, int col, int opti)
{
	char cm1[BUFSIZ];
	char *cm;
#ifdef CONFIG_FEATURE_VI_OPTIMIZE_CURSOR
	char cm2[BUFSIZ];
	Byte *screenp;
	// char cm3[BUFSIZ];
	int Rrow= last_row;
#endif							/* CONFIG_FEATURE_VI_OPTIMIZE_CURSOR */

	memset(cm1, '\0', BUFSIZ - 1);  // clear the buffer

	if (row < 0) row = 0;
	if (row >= rows) row = rows - 1;
	if (col < 0) col = 0;
	if (col >= columns) col = columns - 1;

	//----- 1.  Try the standard terminal ESC sequence
	sprintf((char *) cm1, CMrc, row + 1, col + 1);
	cm= cm1;
	if (! opti) goto pc0;

#ifdef CONFIG_FEATURE_VI_OPTIMIZE_CURSOR
	//----- find the minimum # of chars to move cursor -------------
	//----- 2.  Try moving with discreet chars (Newline, [back]space, ...)
	memset(cm2, '\0', BUFSIZ - 1);  // clear the buffer

	// move to the correct row
	while (row < Rrow) {
		// the cursor has to move up
		strcat(cm2, CMup);
		Rrow--;
	}
	while (row > Rrow) {
		// the cursor has to move down
		strcat(cm2, CMdown);
		Rrow++;
	}

	// now move to the correct column
	strcat(cm2, "\r");			// start at col 0
	// just send out orignal source char to get to correct place
	screenp = &screen[row * columns];	// start of screen line
	strncat(cm2, screenp, col);

	//----- 3.  Try some other way of moving cursor
	//---------------------------------------------

	// pick the shortest cursor motion to send out
	cm= cm1;
	if (strlen(cm2) < strlen(cm)) {
		cm= cm2;
	}  /* else if (strlen(cm3) < strlen(cm)) {
		cm= cm3;
	} */
#endif							/* CONFIG_FEATURE_VI_OPTIMIZE_CURSOR */
  pc0:
	write1(cm);                 // move the cursor
}

//----- Erase from cursor to end of line -----------------------
static void clear_to_eol()
{
	write1(Ceol);   // Erase from cursor to end of line
}

//----- Erase from cursor to end of screen -----------------------
static void clear_to_eos()
{
	write1(Ceos);   // Erase from cursor to end of screen
}

//----- Start standout mode ------------------------------------
static void standout_start() // send "start reverse video" sequence
{
	write1(SOs);     // Start reverse video mode
}

//----- End standout mode --------------------------------------
static void standout_end() // send "end reverse video" sequence
{
	write1(SOn);     // End reverse video mode
}

//----- Flash the screen  --------------------------------------
static void flash(int h)
{
	standout_start();	// send "start reverse video" sequence
	redraw(TRUE);
	(void) mysleep(h);
	standout_end();		// send "end reverse video" sequence
	redraw(TRUE);
}

static void Indicate_Error(void)
{
#ifdef CONFIG_FEATURE_VI_CRASHME
	if (crashme > 0)
		return;			// generate a random command
#endif							/* CONFIG_FEATURE_VI_CRASHME */
	if (!err_method) {
		write1(bell);   // send out a bell character
	} else {
		flash(10);
	}
}

//----- Screen[] Routines --------------------------------------
//----- Erase the Screen[] memory ------------------------------
static void screen_erase()
{
	memset(screen, ' ', screensize);	// clear new screen
}

//----- Draw the status line at bottom of the screen -------------
static void show_status_line(void)
{
	static int last_cksum;
	int l, cnt, cksum;

	cnt = strlen((char *) status_buffer);
	for (cksum= l= 0; l < cnt; l++) { cksum += (int)(status_buffer[l]); }
	// don't write the status line unless it changes
	if (cnt > 0 && last_cksum != cksum) {
		last_cksum= cksum;		// remember if we have seen this line
		place_cursor(rows - 1, 0, FALSE);	// put cursor on status line
		write1(status_buffer);
		clear_to_eol();
		place_cursor(crow, ccol, FALSE);	// put cursor back in correct place
	}
}

//----- format the status buffer, the bottom line of screen ------
// print status buffer, with STANDOUT mode
static void psbs(const char *format, ...)
{
	va_list args;

	va_start(args, format);
	strcpy((char *) status_buffer, SOs);	// Terminal standout mode on
	vsprintf((char *) status_buffer + strlen((char *) status_buffer), format,
			 args);
	strcat((char *) status_buffer, SOn);	// Terminal standout mode off
	va_end(args);

	return;
}

// print status buffer
static void psb(const char *format, ...)
{
	va_list args;

	va_start(args, format);
	vsprintf((char *) status_buffer, format, args);
	va_end(args);
	return;
}

static void ni(Byte * s) // display messages
{
	Byte buf[BUFSIZ];

	print_literal(buf, s);
	psbs("\'%s\' is not implemented", buf);
}

static void edit_status(void)	// show file status on status line
{
	int cur, tot, percent;

	cur = count_lines(text, dot);
	tot = count_lines(text, end - 1);
	//    current line         percent
	//   -------------    ~~ ----------
	//    total lines            100
	if (tot > 0) {
		percent = (100 * cur) / tot;
	} else {
		cur = tot = 0;
		percent = 100;
	}
	psb("\"%s\""
#ifdef CONFIG_FEATURE_VI_READONLY
		"%s"
#endif							/* CONFIG_FEATURE_VI_READONLY */
		"%s line %d of %d --%d%%--",
		(cfn != 0 ? (char *) cfn : "No file"),
#ifdef CONFIG_FEATURE_VI_READONLY
		((vi_readonly || readonly) ? " [Read only]" : ""),
#endif							/* CONFIG_FEATURE_VI_READONLY */
		(file_modified ? " [modified]" : ""),
		cur, tot, percent);
}

//----- Force refresh of all Lines -----------------------------
static void redraw(int full_screen)
{
	place_cursor(0, 0, FALSE);	// put cursor in correct place
	clear_to_eos();		// tel terminal to erase display
	screen_erase();		// erase the internal screen buffer
	refresh(full_screen);	// this will redraw the entire display
}

//----- Format a text[] line into a buffer ---------------------
static void format_line(Byte *dest, Byte *src, int li)
{
	int co;
	Byte c;

	for (co= 0; co < MAX_SCR_COLS; co++) {
		c= ' ';		// assume blank
		if (li > 0 && co == 0) {
			c = '~';        // not first line, assume Tilde
		}
		// are there chars in text[] and have we gone past the end
		if (text < end && src < end) {
			c = *src++;
		}
		if (c == '\n')
			break;
		if (c > 127 && !Isprint(c)) {
			c = '.';
		}
		if (c < ' ' || c == 127) {
			if (c == '\t') {
				c = ' ';
				//       co %    8     !=     7
				for (; (co % tabstop) != (tabstop - 1); co++) {
					dest[co] = c;
				}
			} else {
				dest[co++] = '^';
				if(c == 127)
					c = '?';
				 else
					c += '@';       // make it visible
			}
		}
		// the co++ is done here so that the column will
		// not be overwritten when we blank-out the rest of line
		dest[co] = c;
		if (src >= end)
			break;
	}
}

//----- Refresh the changed screen lines -----------------------
// Copy the source line from text[] into the buffer and note
// if the current screenline is different from the new buffer.
// If they differ then that line needs redrawing on the terminal.
//
static void refresh(int full_screen)
{
	static int old_offset;
	int li, changed;
	Byte buf[MAX_SCR_COLS];
	Byte *tp, *sp;		// pointer into text[] and screen[]
#ifdef CONFIG_FEATURE_VI_OPTIMIZE_CURSOR
	int last_li= -2;				// last line that changed- for optimizing cursor movement
#endif							/* CONFIG_FEATURE_VI_OPTIMIZE_CURSOR */

#ifdef CONFIG_FEATURE_VI_WIN_RESIZE
	window_size_get(0);
#endif							/* CONFIG_FEATURE_VI_WIN_RESIZE */
	sync_cursor(dot, &crow, &ccol);	// where cursor will be (on "dot")
	tp = screenbegin;	// index into text[] of top line

	// compare text[] to screen[] and mark screen[] lines that need updating
	for (li = 0; li < rows - 1; li++) {
		int cs, ce;				// column start & end
		memset(buf, ' ', MAX_SCR_COLS);		// blank-out the buffer
		buf[MAX_SCR_COLS-1] = 0;		// NULL terminate the buffer
		// format current text line into buf
		format_line(buf, tp, li);

		// skip to the end of the current text[] line
		while (tp < end && *tp++ != '\n') /*no-op*/ ;

		// see if there are any changes between vitual screen and buf
		changed = FALSE;	// assume no change
		cs= 0;
		ce= columns-1;
		sp = &screen[li * columns];	// start of screen line
		if (full_screen) {
			// force re-draw of every single column from 0 - columns-1
			goto re0;
		}
		// compare newly formatted buffer with virtual screen
		// look forward for first difference between buf and screen
		for ( ; cs <= ce; cs++) {
			if (buf[cs + offset] != sp[cs]) {
				changed = TRUE;	// mark for redraw
				break;
			}
		}

		// look backward for last difference between buf and screen
		for ( ; ce >= cs; ce--) {
			if (buf[ce + offset] != sp[ce]) {
				changed = TRUE;	// mark for redraw
				break;
			}
		}
		// now, cs is index of first diff, and ce is index of last diff

		// if horz offset has changed, force a redraw
		if (offset != old_offset) {
  re0:
			changed = TRUE;
		}

		// make a sanity check of columns indexes
		if (cs < 0) cs= 0;
		if (ce > columns-1) ce= columns-1;
		if (cs > ce) {  cs= 0;  ce= columns-1;  }
		// is there a change between vitual screen and buf
		if (changed) {
			//  copy changed part of buffer to virtual screen
			memmove(sp+cs, buf+(cs+offset), ce-cs+1);

			// move cursor to column of first change
			if (offset != old_offset) {
				// opti_cur_move is still too stupid
				// to handle offsets correctly
				place_cursor(li, cs, FALSE);
			} else {
#ifdef CONFIG_FEATURE_VI_OPTIMIZE_CURSOR
				// if this just the next line