js/editline/editline.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Simmule Turner and Rich Salz.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * Copyright 1992,1993 Simmule Turner and Rich Salz.  All rights reserved.
 *
 * This software is not subject to any license of the American Telephone
 * and Telegraph Company or of the Regents of the University of California.
 *
 * Permission is granted to anyone to use this software for any purpose on
 * any computer system, and to alter it and redistribute it freely, subject
 * to the following restrictions:
 * 1. The authors are not responsible for the consequences of use of this
 *    software, no matter how awful, even if they arise from flaws in it.
 * 2. The origin of this software must not be misrepresented, either by
 *    explicit claim or by omission.  Since few users ever read sources,
 *    credits must appear in the documentation.
 * 3. Altered versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.  Since few users
 *    ever read sources, credits must appear in the documentation.
 * 4. This notice may not be removed or altered.
 */


/*
**  Main editing routines for editline library.
*/
#include "editline.h"
#include <signal.h>
#include <ctype.h>
#include <unistd.h>

/*
**  Manifest constants.
*/
#define SCREEN_WIDTH    80
#define SCREEN_ROWS     24
#define NO_ARG          (-1)
#define DEL             127
#define CTL(x)          ((x) & 0x1F)
#define ISCTL(x)        ((x) && (x) < ' ')
#define UNCTL(x)        ((x) + 64)
#define META(x)         ((x) | 0x80)
#define ISMETA(x)       ((x) & 0x80)
#define UNMETA(x)       ((x) & 0x7F)
#if     !defined(HIST_SIZE)
#define HIST_SIZE       20
#endif  /* !defined(HIST_SIZE) */

/*
**  Command status codes.
*/
typedef enum _STATUS {
    CSdone, CSeof, CSmove, CSdispatch, CSstay, CSsignal
} STATUS;

/*
**  The type of case-changing to perform.
*/
typedef enum _CASE {
    TOupper, TOlower
} CASE;

/*
**  Key to command mapping.
*/
typedef struct _KEYMAP {
    CHAR        Key;
    STATUS      (*Function)();
} KEYMAP;

/*
**  Command history structure.
*/
typedef struct _HISTORY {
    int         Size;
    int         Pos;
    CHAR        *Lines[HIST_SIZE];
} HISTORY;

/*
**  Globals.
*/
int             rl_eof;
int             rl_erase;
int             rl_intr;
int             rl_kill;
int             rl_quit;

STATIC CHAR             NIL[] = "";
STATIC CONST CHAR       *Input = NIL;
STATIC CHAR             *Line;
STATIC CONST char       *Prompt;
STATIC CHAR             *Yanked;
STATIC char             *Screen;
STATIC char             NEWLINE[]= CRLF;
STATIC HISTORY          H;
STATIC int              Repeat;
STATIC int              End;
STATIC int              Mark;
STATIC int              OldPoint;
STATIC int              Point;
STATIC int              PushBack;
STATIC int              Pushed;
STATIC int              Signal;
FORWARD KEYMAP          Map[32];
FORWARD KEYMAP          MetaMap[16];
STATIC SIZE_T           Length;
STATIC SIZE_T           ScreenCount;
STATIC SIZE_T           ScreenSize;
STATIC char             *backspace;
STATIC int              TTYwidth;
STATIC int              TTYrows;

/* Display print 8-bit chars as `M-x' or as the actual 8-bit char? */
int             rl_meta_chars = 0;

/*
**  Declarations.
*/
STATIC CHAR     *editinput();
#if     defined(USE_TERMCAP)
#include <stdlib.h>
#include <curses.h>
#include <term.h>
#endif  /* defined(USE_TERMCAP) */

/*
**  TTY input/output functions.
*/

STATIC void
TTYflush()
{
    if (ScreenCount) {
        (void)write(1, Screen, ScreenCount);
        ScreenCount = 0;
    }
}

STATIC void
TTYput(c)
    CHAR        c;
{
    Screen[ScreenCount] = c;
    if (++ScreenCount >= ScreenSize - 1) {
        ScreenSize += SCREEN_INC;
        RENEW(Screen, char, ScreenSize);
    }
}

STATIC void
TTYputs(p)
    CHAR        *p;
{
    while (*p)
        TTYput(*p++);
}

STATIC void
TTYshow(c)
    CHAR        c;
{
    if (c == DEL) {
        TTYput('^');
        TTYput('?');
    }
    else if (ISCTL(c)) {
        TTYput('^');
        TTYput(UNCTL(c));
    }
    else if (rl_meta_chars && ISMETA(c)) {
        TTYput('M');
        TTYput('-');
        TTYput(UNMETA(c));
    }
    else
        TTYput(c);
}

STATIC void
TTYstring(p)
    CHAR        *p;
{
    while (*p)
        TTYshow(*p++);
}

STATIC unsigned int
TTYget()
{
    CHAR        c;

    TTYflush();
    if (Pushed) {
        Pushed = 0;
        return PushBack;
    }
    if (*Input)
        return *Input++;
    return read(0, &c, (SIZE_T)1) == 1 ? c : EOF;
}

#define TTYback()       (backspace ? TTYputs((CHAR *)backspace) : TTYput('\b'))

STATIC void
TTYbackn(n)
    int         n;
{
    while (--n >= 0)
        TTYback();
}

STATIC void
TTYinfo()
{
    static int          init;
#if     defined(USE_TERMCAP)
    char                *term;
    char                buff[2048];
    char                *bp, *p;
#endif  /* defined(USE_TERMCAP) */
#if     defined(TIOCGWINSZ)
    struct winsize      W;
#endif  /* defined(TIOCGWINSZ) */

    if (init) {
#if     defined(TIOCGWINSZ)
        /* Perhaps we got resized. */
        if (ioctl(0, TIOCGWINSZ, &W) >= 0
         && W.ws_col > 0 && W.ws_row > 0) {
            TTYwidth = (int)W.ws_col;
            TTYrows = (int)W.ws_row;
        }
#endif  /* defined(TIOCGWINSZ) */
        return;
    }
    init++;

    TTYwidth = TTYrows = 0;
#if     defined(USE_TERMCAP)
    bp = &buff[0];
    if ((term = getenv("TERM")) == NULL)
        term = "dumb";
    if (tgetent(buff, term) < 0) {
       TTYwidth = SCREEN_WIDTH;
       TTYrows = SCREEN_ROWS;
       return;
    }
    p = tgetstr("le", &bp);
    backspace = p ? strdup(p) : NULL;
    TTYwidth = tgetnum("co");
    TTYrows = tgetnum("li");
#endif  /* defined(USE_TERMCAP) */

#if     defined(TIOCGWINSZ)
    if (ioctl(0, TIOCGWINSZ, &W) >= 0) {
        TTYwidth = (int)W.ws_col;
        TTYrows = (int)W.ws_row;
    }
#endif  /* defined(TIOCGWINSZ) */

    if (TTYwidth <= 0 || TTYrows <= 0) {
        TTYwidth = SCREEN_WIDTH;
        TTYrows = SCREEN_ROWS;
    }
}


STATIC void
reposition()
{
    int         i;
    CHAR        *p;

    TTYput('\r');
    TTYputs((CONST CHAR *)Prompt);
    for (i = Point, p = Line; --i >= 0; p++)
        TTYshow(*p);
}

STATIC void
left(Change)
    STATUS      Change;
{
    TTYback();
    if (Point) {
        if (ISCTL(Line[Point - 1]))
            TTYback();
        else if (rl_meta_chars && ISMETA(Line[Point - 1])) {
            TTYback();
            TTYback();
        }
    }
    if (Change == CSmove)
        Point--;
}

STATIC void
right(Change)
    STATUS      Change;
{
    TTYshow(Line[Point]);
    if (Change == CSmove)
        Point++;
}

STATIC STATUS
ring_bell()
{
    TTYput('\07');
    TTYflush();
    return CSstay;
}

STATIC STATUS
do_macro(c)
    unsigned int        c;
{
    CHAR                name[4];

    name[0] = '_';
    name[1] = c;
    name[2] = '_';
    name[3] = '\0';

    if ((Input = (CHAR *)getenv((char *)name)) == NULL) {
        Input = NIL;
        return ring_bell();
    }
    return CSstay;
}

STATIC STATUS
do_forward(move)
    STATUS      move;
{
    int         i;
    CHAR        *p;

    i = 0;
    do {
        p = &Line[Point];
        for ( ; Point < End && (*p == ' ' || !isalnum(*p)); Point++, p++)
            if (move == CSmove)
                right(CSstay);

        for (; Point < End && isalnum(*p); Point++, p++)
            if (move == CSmove)
                right(CSstay);

        if (Point == End)
            break;
    } while (++i < Repeat);

    return CSstay;
}

STATIC STATUS
do_case(type)
    CASE        type;
{
    int         i;
    int         end;
    int         count;
    CHAR        *p;

    (void)do_forward(CSstay);
    if (OldPoint != Point) {
        if ((count = Point - OldPoint) < 0)
            count = -count;
        Point = OldPoint;
        if ((end = Point + count) > End)
            end = End;
        for (i = Point, p = &Line[i]; i < end; i++, p++) {
            if (type == TOupper) {
                if (islower(*p))
                    *p = toupper(*p);
            }
            else if (isupper(*p))
                *p = tolower(*p);
            right(CSmove);
        }
    }
    return CSstay;
}

STATIC STATUS
case_down_word()
{
    return do_case(TOlower);
}

STATIC STATUS
case_up_word()
{
    return do_case(TOupper);
}

STATIC void
ceol()
{
    int         extras;
    int         i;
    CHAR        *p;

    for (extras = 0, i = Point, p = &Line[i]; i <= End; i++, p++) {
        TTYput(' ');
        if (ISCTL(*p)) {
            TTYput(' ');
            extras++;
        }
        else if (rl_meta_chars && ISMETA(*p)) {
            TTYput(' ');
            TTYput(' ');
            extras += 2;
        }
    }

    for (i += extras; i > Point; i--)
        TTYback();
}

STATIC void
clear_line()
{
    Point = -strlen(Prompt);
    TTYput('\r');
    ceol();
    Point = 0;
    End = 0;
    Line[0] = '\0';
}

STATIC STATUS
insert_string(p)
    CHAR        *p;
{
    SIZE_T      len;
    int         i;
    CHAR        *new;
    CHAR        *q;

    len = strlen((char *)p);
    if (End + len >= Length) {
        if ((new = NEW(CHAR, Length + len + MEM_INC)) == NULL)
            return CSstay;
        if (Length) {
            COPYFROMTO(new, Line, Length);
            DISPOSE(Line);
        }
        Line = new;
        Length += len + MEM_INC;
    }

    for (q = &Line[Point], i = End - Point; --i >= 0; )
        q[len + i] = q[i];
    COPYFROMTO(&Line[Point], p, len);
    End += len;
    Line[End] = '\0';
    TTYstring(&Line[Point]);
    Point += len;

    return Point == End ? CSstay : CSmove;
}

STATIC STATUS
redisplay()
{
    TTYputs((CONST CHAR *)NEWLINE);
    TTYputs((CONST CHAR *)Prompt);
    TTYstring(Line);
    return CSmove;
}

STATIC STATUS
toggle_meta_mode()
{
    rl_meta_chars = ! rl_meta_chars;
    return redisplay();
}


STATIC CHAR *
next_hist()
{
    return H.Pos >= H.Size - 1 ? NULL : H.Lines[++H.Pos];
}

STATIC CHAR *
prev_hist()
{
    return H.Pos == 0 ? NULL : H.Lines[--H.Pos];
}

STATIC STATUS
do_insert_hist(p)
    CHAR        *p;
{
    if (p == NULL)
        return ring_bell();
    Point = 0;
    reposition();
    ceol();
    End = 0;
    return insert_string(p);
}

STATIC STATUS
do_hist(move)
    CHAR        *(*move)();
{
    CHAR        *p;
    int         i;

    i = 0;
    do {
        if ((p = (*move)()) == NULL)
            return ring_bell();
    } while (++i < Repeat);
    return do_insert_hist(p);
}

STATIC STATUS
h_next()
{
    return do_hist(next_hist);
}

STATIC STATUS
h_prev()
{
    return do_hist(prev_hist);
}

STATIC STATUS
h_first()
{
    return do_insert_hist(H.Lines[H.Pos = 0]);
}

STATIC STATUS
h_last()
{
    return do_insert_hist(H.Lines[H.Pos = H.Size - 1]);
}

/*
**  Return zero if pat appears as a substring in text.
*/
STATIC int
substrcmp(text, pat, len)
    char        *text;
    char        *pat;
    int         len;
{
    char        c;

    if ((c = *pat) == '\0')
        return *text == '\0';
    for ( ; *text; text++)
        if (*text == c && strncmp(text, pat, len) == 0)
            return 0;
    return 1;
}

STATIC CHAR *
search_hist(search, move)
    CHAR        *search;
    CHAR        *(*move)();
{
    static CHAR *old_search;
    int         len;
    int         pos;
    int         (*match)();
    char        *pat;

    /* Save or get remembered search pattern. */
    if (search && *search) {
        if (old_search)
            DISPOSE(old_search);
        old_search = (CHAR *)strdup((char *)search);
    }
    else {
        if (old_search == NULL || *old_search == '\0')
            return NULL;
        search = old_search;
    }

    /* Set up pattern-finder. */
    if (*search == '^') {
        match = strncmp;
        pat = (char *)(search + 1);
    }
    else {
        match = substrcmp;
        pat = (char *)search;
    }
    len = strlen(pat);

    for (pos = H.Pos; (*move)() != NULL; )
        if ((*match)((char *)H.Lines[H.Pos], pat, len) == 0)
            return H.Lines[H.Pos];
    H.Pos = pos;
    return NULL;
}

STATIC STATUS
h_search()
{
    static int  Searching;
    CONST char  *old_prompt;
    CHAR        *(*move)();
    CHAR        *p;

    if (Searching)
        return ring_bell();
    Searching = 1;

    clear_line();
    old_prompt = Prompt;
    Prompt = "Search: ";
    TTYputs((CONST CHAR *)Prompt);
    move = Repeat == NO_ARG ? prev_hist : next_hist;
    p = editinput();
    Prompt = old_prompt;
    Searching = 0;
    TTYputs((CONST CHAR *)Prompt);
    if (p == NULL && Signal > 0) {
        Signal = 0;
        clear_line();
        return redisplay();
    }
    p = search_hist(p, move);
    clear_line();
    if (p == NULL) {
        (void)ring_bell();
        return redisplay();
    }
    return do_insert_hist(p);
}

STATIC STATUS
fd_char()
{
    int         i;

    i = 0;
    do {
        if (Point >= End)
            break;
        right(CSmove);
    } while (++i < Repeat);
    return CSstay;
}

STATIC void
save_yank(begin, i)
    int         begin;
    int         i;
{
    if (Yanked) {
        DISPOSE(Yanked);
        Yanked = NULL;
    }

    if (i < 1)
        return;

    if ((Yanked = NEW(CHAR, (SIZE_T)i + 1)) != NULL) {
        COPYFROMTO(Yanked, &Line[begin], i);
        Yanked[i] = '\0';
    }
}

STATIC STATUS
delete_string(count)
    int         count;
{
    int         i;
    CHAR        *p;

    if (count <= 0 || End == Point)
        return ring_bell();

    if (count == 1 && Point == End - 1) {
        /* Optimize common case of delete at end of line. */
        End--;
        p = &Line[Point];
        i = 1;
        TTYput(' ');
        if (ISCTL(*p)) {
            i = 2;
            TTYput(' ');
        }
        else if (rl_meta_chars && ISMETA(*p)) {
            i = 3;
            TTYput(' ');
            TTYput(' ');
        }
        TTYbackn(i);
        *p = '\0';
        return CSmove;
    }
    if (Point + count > End && (count = End - Point) <= 0)
        return CSstay;

    if (count > 1)
        save_yank(Point, count);

    for (p = &Line[Point], i = End - (Point + count) + 1; --i >= 0; p++)
        p[0] = p[count];
    ceol();
    End -= count;
    TTYstring(&Line[Point]);
    return CSmove;
}

STATIC STATUS
bk_char()
{
    int         i;

    i = 0;
    do {
        if (Point == 0)
            break;
        left(CSmove);
    } while (++i < Repeat);

    return CSstay;
}

STATIC STATUS
bk_del_char()
{
    int         i;

    i = 0;
    do {
        if (Point == 0)
            break;
        left(CSmove);
    } while (++i < Repeat);

    return delete_string(i);
}

STATIC STATUS
kill_line()
{
    int         i;

    if (Repeat != NO_ARG) {
        if (Repeat < Point) {
            i = Point;
            Point = Repeat;
            reposition();
            (void)delete_string(i - Point);
        }
        else if (Repeat > Point) {
            right(CSmove);
            (void)delete_string(Repeat - Point - 1);
        }
        return CSmove;
    }

    save_yank(Point, End - Point);
    Line[Point] = '\0';
    ceol();
    End = Point;
    return CSstay;
}

STATIC STATUS
insert_char(c)
    int         c;
{
    STATUS      s;
    CHAR        buff[2];
    CHAR        *p;
    CHAR        *q;
    int         i;

    if (Repeat == NO_ARG || Repeat < 2) {
        buff[0] = c;
        buff[1] = '\0';
        return insert_string(buff);
    }

    if ((p = NEW(CHAR, Repeat + 1)) == NULL)
        return CSstay;
    for (i = Repeat, q = p; --i >= 0; )
        *q++ = c;
    *q = '\0';
    Repeat = 0;
    s = insert_string(p);
    DISPOSE(p);
    return s;
}

STATIC STATUS
meta()
{
    unsigned int        c;
    KEYMAP              *kp;

    if ((c = TTYget()) == EOF)
        return CSeof;
#if     defined(ANSI_ARROWS)
    /* Also include VT-100 arrows. */
    if (c == '[' || c == 'O')
        switch (c = TTYget()) {
        default:        return ring_bell();
        case EOF:       return CSeof;
        case 'A':       return h_prev();
        case 'B':       return h_next();
        case 'C':       return fd_char();
        case 'D':       return bk_char();
        }
#endif  /* defined(ANSI_ARROWS) */

    if (isdigit(c)) {
        for (Repeat = c - '0'; (c = TTYget()) != EOF && isdigit(c); )
            Repeat = Repeat * 10 + c - '0';
        Pushed = 1;
        PushBack = c;
        return CSstay;
    }

    if (isupper(c))
        return do_macro(c);
    for (OldPoint = Point, kp = MetaMap; kp->Function; kp++)
        if (kp->Key == c)
            return (*kp->Function)();

    return ring_bell();
}

STATIC STATUS
emacs(c)
    unsigned int        c;
{
    STATUS              s;
    KEYMAP              *kp;

    if (rl_meta_chars && ISMETA(c)) {
        Pushed = 1;
        PushBack = UNMETA(c);
        return meta();
    }
    for (kp = Map; kp->Function; kp++)
        if (kp->Key == c)
            break;
    s = kp->Function ? (*kp->Function)() : insert_char((int)c);
    if (!Pushed)
        /* No pushback means no repeat count; hacky, but true. */
        Repeat = NO_ARG;
    return s;
}

STATIC STATUS
TTYspecial(c)
    unsigned int        c;
{
    if (ISMETA(c))
        return CSdispatch;

    if (c == rl_erase || c == DEL)
        return bk_del_char();
    if (c == rl_kill) {
        if (Point != 0) {
            Point = 0;
            reposition();
        }
        Repeat = NO_ARG;
        return kill_line();
    }
    if (c == rl_eof && Point == 0 && End == 0)
        return CSeof;
    if (c == rl_intr) {
        Signal = SIGINT;
        return CSsignal;
    }
    if (c == rl_quit) {
        Signal = SIGQUIT;
        return CSeof;
    }

    return CSdispatch;
}

STATIC CHAR *
editinput()
{
    unsigned int        c;

    Repeat = NO_ARG;
    OldPoint = Point = Mark = End = 0;
    Line[0] = '\0';

    Signal = -1;
    while ((c = TTYget()) != EOF)
        switch (TTYspecial(c)) {
        case CSdone:
            return Line;
        case CSeof:
            return NULL;
        case CSsignal:
            return (CHAR *)"";
        case CSmove:
            reposition();
            break;
        case CSdispatch:
            switch (emacs(c)) {
            case CSdone:
                return Line;
            case CSeof:
                return NULL;
            case CSsignal:
                return (CHAR *)"";
            case CSmove:
                reposition();
                break;
            case CSdispatch:
            case CSstay:
                break;
            }
            break;
        case CSstay:
            break;
        }
    return NULL;
}

STATIC void
hist_add(p)
    CHAR        *p;
{
    int         i;

    if ((p = (CHAR *)strdup((char *)p)) == NULL)
        return;
    if (H.Size < HIST_SIZE)
        H.Lines[H.Size++] = p;
    else {
        DISPOSE(H.Lines[0]);
        for (i = 0; i < HIST_SIZE - 1; i++)
            H.Lines[i] = H.Lines[i + 1];
        H.Lines[i] = p;
    }
    H.Pos = H.Size - 1;
}

/*
**  For compatibility with FSF readline.
*/
/* ARGSUSED0 */
void
rl_reset_terminal(p)
    char        *p;
{
}

void
rl_initialize()
{
}

char *
readline(prompt)
    CONST char  *prompt;
{
    CHAR        *line;
    int         s;

    if (Line == NULL) {
        Length = MEM_INC;
        if ((Line = NEW(CHAR, Length)) == NULL)
            return NULL;
    }

    TTYinfo();
    rl_ttyset(0);
    hist_add(NIL);
    ScreenSize = SCREEN_INC;
    Screen = NEW(char, ScreenSize);
    Prompt = prompt ? prompt : (char *)NIL;
    TTYputs((CONST CHAR *)Prompt);
    if ((line = editinput()) != NULL) {
        line = (CHAR *)strdup((char *)line);
        TTYputs((CHAR *)NEWLINE);
        TTYflush();
    }
    rl_ttyset(1);
    DISPOSE(Screen);
    DISPOSE(H.Lines[--H.Size]);
    if (Signal > 0) {
        s = Signal;
        Signal = 0;
        (void)kill(getpid(), s);
    }
    return (char *)line;
}

void
add_history(p)
    char        *p;
{
    if (p == NULL || *p == '\0')
        return;

#if     defined(UNIQUE_HISTORY)
    if (H.Size && strcmp(p, H.Lines[H.Size - 1]) == 0)
        return;
#endif  /* defined(UNIQUE_HISTORY) */
    hist_add((CHAR *)p);
}


STATIC STATUS
beg_line()
{
    if (Point) {
        Point = 0;
        return CSmove;
    }
    return CSstay;
}

STATIC STATUS
del_char()
{
    return delete_string(Repeat == NO_ARG ? 1 : Repeat);
}

STATIC STATUS
end_line()
{
    if (Point != End) {
        Point = End;
        return CSmove;
    }
    return CSstay;
}

STATIC STATUS
accept_line()
{
    Line[End] = '\0';
    return CSdone;
}

STATIC STATUS
transpose()
{
    CHAR        c;

    if (Point) {
        if (Point == End)
            left(CSmove);
        c = Line[Point - 1];
        left(CSstay);
        Line[Point - 1] = Line[Point];
        TTYshow(Line[Point - 1]);
        Line[Point++] = c;
        TTYshow(c);
    }
    return CSstay;
}

STATIC STATUS
quote()
{
    unsigned int        c;

    return (c = TTYget()) == EOF ? CSeof : insert_char((int)c);
}

STATIC STATUS
wipe()
{
    int         i;

    if (Mark > End)
        return ring_bell();

    if (Point > Mark) {
        i = Point;
        Point = Mark;
        Mark = i;
        reposition();
    }

    return delete_string(Mark - Point);
}

STATIC STATUS
mk_set()
{
    Mark = Point;
    return CSstay;
}

STATIC STATUS
exchange()
{
    unsigned int        c;

    if ((c = TTYget()) != CTL('X'))
        return c == EOF ? CSeof : ring_bell();

    if ((c = Mark) <= End) {
        Mark = Point;
        Point = c;
        return CSmove;
    }
    return CSstay;
}

STATIC STATUS
yank()
{
    if (Yanked && *Yanked)
        return insert_string(Yanked);
    return CSstay;
}

STATIC STATUS
copy_region()
{
    if (Mark > End)
        return ring_bell();

    if (Point > Mark)
        save_yank(Mark, Point - Mark);
    else
        save_yank(Point, Mark - Point);

    return CSstay;
}

STATIC STATUS
move_to_char()
{
    unsigned int        c;
    int                 i;
    CHAR                *p;

    if ((c = TTYget()) == EOF)
        return CSeof;
    for (i = Point + 1, p = &Line[i]; i < End; i++, p++)
        if (*p == c) {
            Point = i;
            return CSmove;
        }
    return CSstay;
}

STATIC STATUS
fd_word()
{
    return do_forward(CSmove);
}

STATIC STATUS
fd_kill_word()
{
    int         i;

    (void)do_forward(CSstay);
    if (OldPoint != Point) {
        i = Point - OldPoint;
        Point = OldPoint;
        return delete_string(i);
    }
    return CSstay;
}

STATIC STATUS
bk_word()
{
    int         i;
    CHAR        *p;

    i = 0;
    do {
        for (p = &Line[Point]; p > Line && !isalnum(p[-1]); p--)
            left(CSmove);

        for (; p > Line && p[-1] != ' ' && isalnum(p[-1]); p--)
            left(CSmove);

        if (Point == 0)
            break;
    } while (++i < Repeat);

    return CSstay;
}

STATIC STATUS
bk_kill_word()
{
    (void)bk_word();
    if (OldPoint != Point)
        return delete_string(OldPoint - Point);
    return CSstay;
}

STATIC int
argify(line, avp)
    CHAR        *line;
    CHAR        ***avp;
{
    CHAR        *c;
    CHAR        **p;
    CHAR        **new;
    int         ac;
    int         i;

    i = MEM_INC;
    if ((*avp = p = NEW(CHAR*, i))== NULL)
         return 0;

    for (c = line; isspace(*c); c++)
        continue;
    if (*c == '\n' || *c == '\0')
        return 0;

    for (ac = 0, p[ac++] = c; *c && *c != '\n'; ) {
        if (isspace(*c)) {
            *c++ = '\0';
            if (*c && *c != '\n') {
                if (ac + 1 == i) {
                    new = NEW(CHAR*, i + MEM_INC);
                    if (new == NULL) {
                        p[ac] = NULL;
                        return ac;
                    }
                    COPYFROMTO(new, p, i * sizeof (char **));
                    i += MEM_INC;
                    DISPOSE(p);
                    *avp = p = new;
                }
                p[ac++] = c;
            }
        }
        else
            c++;
    }
    *c = '\0';
    p[ac] = NULL;
    return ac;
}

STATIC STATUS
last_argument()
{
    CHAR        **av;
    CHAR        *p;
    STATUS      s;
    int         ac;

    if (H.Size == 1 || (p = H.Lines[H.Size - 2]) == NULL)
        return ring_bell();

    if ((p = (CHAR *)strdup((char *)p)) == NULL)
        return CSstay;
    ac = argify(p, &av);

    if (Repeat != NO_ARG)
        s = Repeat < ac ? insert_string(av[Repeat]) : ring_bell();
    else
        s = ac ? insert_string(av[ac - 1]) : CSstay;

    if (ac)
        DISPOSE(av);
    DISPOSE(p);
    return s;
}

STATIC KEYMAP   Map[32] = {
    {   CTL('@'),       ring_bell       },
    {   CTL('A'),       beg_line        },
    {   CTL('B'),       bk_char         },
    {   CTL('D'),       del_char        },
    {   CTL('E'),       end_line        },
    {   CTL('F'),       fd_char         },
    {   CTL('G'),       ring_bell       },
    {   CTL('H'),       bk_del_char     },
    {   CTL('J'),       accept_line     },
    {   CTL('K'),       kill_line       },
    {   CTL('L'),       redisplay       },
    {   CTL('M'),       accept_line     },
    {   CTL('N'),       h_next          },
    {   CTL('O'),       ring_bell       },
    {   CTL('P'),       h_prev          },
    {   CTL('Q'),       ring_bell       },
    {   CTL('R'),       h_search        },
    {   CTL('S'),       ring_bell       },
    {   CTL('T'),       transpose       },
    {   CTL('U'),       ring_bell       },
    {   CTL('V'),       quote           },
    {   CTL('W'),       wipe            },
    {   CTL('X'),       exchange        },
    {   CTL('Y'),       yank            },
    {   CTL('Z'),       ring_bell       },
    {   CTL('['),       meta            },
    {   CTL(']'),       move_to_char    },
    {   CTL('^'),       ring_bell       },
    {   CTL('_'),       ring_bell       },
    {   0,              NULL            }
};

STATIC KEYMAP   MetaMap[16]= {
    {   CTL('H'),       bk_kill_word    },
    {   DEL,            bk_kill_word    },
    {   ' ',            mk_set          },
    {   '.',            last_argument   },
    {   '<',            h_first         },
    {   '>',            h_last          },
    {   'b',            bk_word         },
    {   'd',            fd_kill_word    },
    {   'f',            fd_word         },
    {   'l',            case_down_word  },
    {   'm',            toggle_meta_mode },
    {   'u',            case_up_word    },
    {   'y',            yank            },
    {   'w',            copy_region     },
    {   0,              NULL            }
};
