source: neercs/trunk/src/term.c @ 4019

/* 
 *  neercs        console-based window manager
 *  Copyright (c) 2006 Sam Hocevar <sam@zoy.org>
 *                All Rights Reserved
 *
 *  $Id$
 *
 *  This program is free software. It comes without any warranty, to
 *  the extent permitted by applicable law. You can redistribute it
 *  and/or modify it under the terms of the Do What The Fuck You Want
 *  To Public License, Version 2, as published by Sam Hocevar. See
 *  http://sam.zoy.org/wtfpl/COPYING for more details.
 */

#include "config.h"

#define _XOPEN_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#if defined HAVE_PTY_H
#   include <pty.h>             /* for openpty and forkpty */
#else
#   include <util.h>            /* for OS X */
#endif
#include <unistd.h>
#include <fcntl.h>

#include <caca.h>
#include <caca.h>

#include "neercs.h"

/* DEC ACS with common extensions */
static uint32_t dec_acs(uint32_t uc)
{
    switch (uc)
    {
    case '+':
        return 0x2192;          /* RIGHTWARDS ARROW */
    case ',':
        return 0x2190;          /* LEFTWARDS ARROW */
    case '-':
        return 0x2191;          /* UPWARDS ARROW */
    case '.':
        return 0x2193;          /* DOWNWARDS ARROW */
    case '0':
        return 0x25AE;          /* BLACK VERTICAL RECTANGLE */
    case '_':
        return 0x25AE;          /* BLACK VERTICAL RECTANGLE */
    case '`':
        return 0x25C6;          /* BLACK DIAMOND */
    case 'a':
        return 0x2592;          /* MEDIUM SHADE */
    case 'b':
        return 0x2409;          /* SYMBOL FOR HORIZONTAL TABULATION */
    case 'c':
        return 0x240C;          /* SYMBOL FOR FORM FEED */
    case 'd':
        return 0x240D;          /* SYMBOL FOR CARRIAGE RETURN */
    case 'e':
        return 0x240A;          /* SYMBOL FOR LINE FEED */
    case 'f':
        return 0x00B0;          /* DEGREE SIGN */
    case 'g':
        return 0x00B1;          /* PLUS-MINUS SIGN */
    case 'h':
        return 0x2424;          /* SYMBOL FOR NEWLINE */
    case 'i':
        return 0x240B;          /* SYMBOL FOR VERTICAL TABULATION */
    case 'j':
        return 0x2518;          /* BOX DRAWINGS LIGHT UP AND LEFT */
    case 'k':
        return 0x2510;          /* BOX DRAWINGS LIGHT DOWN AND LEFT */
    case 'l':
        return 0x250C;          /* BOX DRAWINGS LIGHT DOWN AND RIGHT */
    case 'm':
        return 0x2514;          /* BOX DRAWINGS LIGHT UP AND RIGHT */
    case 'n':
        return 0x253C;          /* BOX DRAWINGS LIGHT VERTICAL AND HORIZONTAL */
    case 'o':
        return 0x23BA;          /* HORIZONTAL SCAN LINE-1 */
    case 'p':
        return 0x23BB;          /* HORIZONTAL SCAN LINE-3 */
    case 'q':
        return 0x2500;          /* BOX DRAWINGS LIGHT HORIZONTAL */
    case 'r':
        return 0x23BC;          /* HORIZONTAL SCAN LINE-7 */
    case 's':
        return 0x23BD;          /* HORIZONTAL SCAN LINE-9 */
    case 't':
        return 0x251C;          /* BOX DRAWINGS LIGHT VERTICAL AND RIGHT */
    case 'u':
        return 0x2524;          /* BOX DRAWINGS LIGHT VERTICAL AND LEFT */
    case 'v':
        return 0x2534;          /* BOX DRAWINGS LIGHT UP AND HORIZONTAL */
    case 'w':
        return 0x252C;          /* BOX DRAWINGS LIGHT DOWN AND HORIZONTAL */
    case 'x':
        return 0x2502;          /* BOX DRAWINGS LIGHT VERTICAL */
    case 'y':
        return 0x2264;          /* LESS-THAN OR EQUAL TO */
    case 'z':
        return 0x2265;          /* GREATER-THAN OR EQUAL TO */
    case '{':
        return 0x03C0;          /* GREEK SMALL LETTER PI */
    case '|':
        return 0x2260;          /* NOT EQUAL TO */
    case '}':
        return 0x00A3;          /* POUND SIGN */
    case '~':
        return 0x00B7;          /* MIDDLE DOT */
    default:
        return uc;
    }
};

static void reset_conv_state(struct screen *);

#define LITERAL2CHAR(i0,i1) (((i0) << 8) | (i1))

#define LITERAL3CHAR(i0,i1,i2) LITERAL2CHAR(LITERAL2CHAR(i0, i1), i2)

static void ansi_parse_grcm(struct screen *,
                            unsigned int, unsigned int const *);

static int handle_single_char(unsigned char c, int *x, int *y,
                              struct screen_list *screen_list,
                              struct screen *sc);

static int handle_single_char(unsigned char c, int *x, int *y,
                              struct screen_list *screen_list,
                              struct screen *sc)
{
    if (c == '\r')
    {
        *x = 0;
    }

    else if (c == '\n')
    {
        *x = 0;
        *y = *y + 1;
    }
    else if (c == '\a')
    {
        if (!sc->bell)
            screen_list->in_bell++;
        sc->bell = 1;
    }

    else if (c == '\t')
    {
        *x = (*x + 7) & ~7;
    }

    else if (c == '\x08')
    {
        if (*x > 0)
            *x = *x - 1;
    }
    else if (c == '\x0b')
    {
        /* Vertical tab */
        /* Not sure about the real meaning of it, just y++ for now */
        if (*y < caca_get_canvas_height(sc->cv))
            *y = *y + 1;
    }
    else if (c == '\x0e')
    {
        /* Shift Out (Ctrl-N) -> Switch to Alternate Character Set: invokes
           the G1 character set. */
        sc->conv_state.glr[0] = 1;
    }

    else if (c == '\x0f')
    {
        /* Shift In (Ctrl-O) -> Switch to Standard Character Set: invokes the
           G0 character set. */
        sc->conv_state.glr[0] = 0;
    }
    else
    {
        return 1;
    }
    return 0;

}

long int import_term(struct screen_list *screen_list, struct screen *sc,
                     void const *data, unsigned int size)
{
    unsigned char const *buffer = (unsigned char const *)data;
    unsigned int i, j, k, skip, dummy = 0;
    unsigned int width, height, top, bottom;
    uint32_t savedattr;
    int x = 0, y = 0, save_x = 0, save_y = 0;
    char b[100];


    debug("ansi : import_term\n");

    width = caca_get_canvas_width(sc->cv);
    height = caca_get_canvas_height(sc->cv);
    x = caca_get_cursor_x(sc->cv);
    y = caca_get_cursor_y(sc->cv);
    top = 1;
    bottom = height;

    if (!sc->init)
    {
        sc->dfg = CACA_LIGHTGRAY;
        sc->dbg = CACA_BLACK;

        caca_set_color_ansi(sc->cv, sc->dfg, sc->dbg);
        sc->clearattr = caca_get_attr(sc->cv, -1, -1);

        ansi_parse_grcm(sc, 1, &dummy);

        reset_conv_state(sc);

        sc->init = 1;
    }

    for (i = 0; i < size; i += skip)
    {
        uint32_t ch = 0;
        int wch = 0;

        skip = 1;

#define ASCCHAR(c) (c>31&&c<127)?c:'?'
        if (buffer[i] == '\033')
        {
            debug("ansi ESC : '%c%c%c%c%c'\n",
                  ASCCHAR(buffer[i + 1]),
                  ASCCHAR(buffer[i + 2]),
                  ASCCHAR(buffer[i + 3]),
                  ASCCHAR(buffer[i + 4]), ASCCHAR(buffer[i + 5]));
        }

        /* Control codes (ASCII < \x20) */
        if (!handle_single_char(buffer[i], &x, &y, screen_list, sc))
        {
        }

        /* If there are not enough characters to parse the escape sequence,
           wait until the next try. We require 3. */

        else if (buffer[i] == '\033' && i + 2 >= size)
            break;

        /* Single Shift Select of G2 Character Set (SS2: 0x8e): affects next
           character only */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'N')
        {
            sc->conv_state.ss = 2;
            skip += 1;
        }
        /* Reverse Index (RI) go up one line, reverse scroll if necessary */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'M')
        {
            /* FIXME : not sure about the meaning of 'go up one line' and 'if
               necessary' words. Implemented as a scroller only. */
            for (j = bottom - 1; j > top; j--)
            {
                for (k = 0; k < width; k++)
                {
                    caca_put_char(sc->cv, k, j,
                                  caca_get_char(sc->cv, k, j - 1));
                    caca_put_attr(sc->cv, k, j,
                                  caca_get_attr(sc->cv, k, j - 1));
                }
            }
            caca_draw_line(sc->cv, 0, top - 1, width - 1, top - 1, ' ');
            skip += 1;
        }

        /* Single Shift Select of G3 Character Set (SS2: 0x8f): affects next
           character only */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'O')
        {
            sc->conv_state.ss = 3;
            skip += 1;
        }

        /* LOCKING-SHIFT TWO (LS2), ISO 2022, ECMA-48 (1986), ISO 6429 : 1988 */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'n')
        {
            sc->conv_state.glr[0] = 2;
            skip += 1;
        }

        /* LOCKING-SHIFT THREE (LS3) ISO 2022, ECMA-48 (1986), ISO 6429 : 1988 
         */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'o')
        {
            sc->conv_state.glr[0] = 3;
            skip += 1;
        }

        /* RESET TO INITIAL STATE (RIS), ECMA-48 (1986), ISO 6429 : 1988 */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'c')
        {
            sc->dfg = CACA_DEFAULT;
            sc->dbg = CACA_DEFAULT;

            caca_set_color_ansi(sc->cv, sc->dfg, sc->dbg);
            sc->clearattr = caca_get_attr(sc->cv, -1, -1);
            ansi_parse_grcm(sc, 1, &dummy);

            reset_conv_state(sc);
            skip += 1;
        }

        /* Coding Method Delimiter (CMD), ECMA-48 (1991), ISO/IEC 6429:1992
           (ISO IR 189) */
        else if (buffer[i] == '\033' && buffer[i + 1] == 'd')
        {
            reset_conv_state(sc);
            skip += 1;
        }

        /* GZDM4, G0-Designators, multi, 94^n chars [grandfathered short form
           from ISO 2022:1986] */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && (buffer[i + 2] >= '@') && (buffer[i + 2] <= 'C'))
        {
            sc->conv_state.gn[0] = LITERAL2CHAR('$', buffer[i + 2]);
            skip += 2;
        }

        /* GnDMx Gn-Designators, 9x^n chars; need one more char to distinguish 
           these */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && (i + 3 >= size))
            break;

        /* GZD4 G0-Designator, 94 chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '(')
        {
            sc->conv_state.gn[0] = buffer[i + 2];
            skip += 2;
        }

        /* G1D4 G1-Designator, 94 chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == ')')
        {
            sc->conv_state.gn[1] = buffer[i + 2];
            skip += 2;
        }

        /* G2D4 G2-Designator, 94 chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '*')
        {
            sc->conv_state.gn[2] = buffer[i + 2];
            skip += 2;
        }

        /* G3D4 G3-Designator, 94 chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '+')
        {
            sc->conv_state.gn[3] = buffer[i + 2];
            skip += 2;
        }

        /* G2D6 G2-Designator, 96 chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '.')
        {
            sc->conv_state.gn[2] = LITERAL2CHAR('.', buffer[i + 2]);
            skip += 2;
        }

        /* G3D6 G3-Designator, 96 chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '/')
        {
            sc->conv_state.gn[3] = LITERAL2CHAR('.', buffer[i + 2]);
            skip += 2;
        }

        /* GZDM4 G0-Designator, 94^n chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && buffer[i + 2] == '(')
        {
            sc->conv_state.gn[0] = LITERAL2CHAR('$', buffer[i + 3]);
            skip += 3;
        }

        /* G1DM4 G1-Designator, 94^n chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && buffer[i + 2] == ')')
        {
            sc->conv_state.gn[1] = LITERAL2CHAR('$', buffer[i + 3]);
            skip += 3;
        }

        /* G2DM4 G2-Designator, 94^n chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && buffer[i + 2] == '*')
        {
            sc->conv_state.gn[2] = LITERAL2CHAR('$', buffer[i + 3]);
            skip += 3;
        }

        /* G3DM4 G3-Designator, 94^n chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && buffer[i + 2] == '+')
        {
            sc->conv_state.gn[3] = LITERAL2CHAR('$', buffer[i + 3]);
            skip += 3;
        }

        /* G2DM6 G2-Designator, 96^n chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && buffer[i + 2] == '.')
        {
            sc->conv_state.gn[2] = LITERAL3CHAR('$', '.', buffer[i + 3]);
            skip += 3;
        }

        /* G3DM6 G3-Designator, 96^n chars */
        else if (buffer[i] == '\033' && buffer[i + 1] == '$'
                 && buffer[i + 2] == '/')
        {
            sc->conv_state.gn[3] = LITERAL3CHAR('$', '.', buffer[i + 3]);
            skip += 3;
        }
        else if (buffer[i] == '\033' && buffer[i + 1] == '#')
        {
            debug("ansi private '#' sequence\n");

            switch (buffer[i + 2])
            {
            case '8':          /* DECALN Fills the entire screen area with
                                   uppercase Es for screen focus and
                                   alignment. */
                for (j = 0; j < height; j++)
                {
                    for (k = 0; k < width; k++)
                    {
                        caca_put_char(sc->cv, k, j, 'E');
                    }
                }
                skip += 2;
                break;

            default:
                debug("Unknow private sequence 'ESC#%c'\n", buffer[i + 2]);
                continue;
            }

        }
        /* Interpret escape commands, as per Standard ECMA-48 "Control
           Functions for Coded Character Sets", 5.4. Control sequences. */
        else if (buffer[i] == '\033' && buffer[i + 1] == '[')
        {
            unsigned int argc = 0, argv[101];
            unsigned int param, inter, junk, final;


            /* Compute offsets to parameter bytes, intermediate bytes and to
               the final byte. Only the final byte is mandatory, there can be
               zero of the others. 0 param=2 inter final final+1
               +-----+------------------+---------------------+-----------------+
               | CSI | parameter bytes | intermediate bytes | final byte | | |
               0x30 - 0x3f | 0x20 - 0x2f | 0x40 - 0x7e | | ^[[ | 0123456789:;<=>?
               | SPC !"#$%&'()*+,-./ | azAZ@[\]^_`{|}~ |
               +-----+------------------+---------------------+-----------------+ */
            param = 2;

            /* vttest use to interleave control characters (\014 CR or \010
               BS) into CSI sequences, either directly after ESC[ or after
               param. Can't find anything related to this in any documentation 
               nor XTerm sources, thought. */

            for (junk = param; i + junk < size; junk++)
                if (buffer[i + junk] < 0x20)
                {
                    handle_single_char(buffer[i + junk], &x, &y, screen_list,
                                       sc);
                }
                else
                {
                    break;
                }

            /* Intermediate offset */
            for (inter = junk; i + inter < size; inter++)
                if (buffer[i + inter] < 0x30 || buffer[i + inter] > 0x3f)
                {
                    break;
                }
            /* Interleaved character */
            for (junk = inter; i + junk < size; junk++)
                if (buffer[i + junk] < 0x20)
                {
                    handle_single_char(buffer[i + junk], &x, &y, screen_list,
                                       sc);
                }
                else
                {
                    break;
                }

            /* Final Byte offset */
            for (final = junk; i + final < size; final++)
                if (buffer[i + final] < 0x20 || buffer[i + final] > 0x2f)
                {
                    break;
                }
            if (i + final >= size
                || buffer[i + final] < 0x40 || buffer[i + final] > 0x7e)
            {
                debug("ansi Invalid Final Byte (%d %c)\n", buffer[i + final],
                      buffer[i + final]);
                break;          /* Invalid Final Byte */
            }

            skip += final;

            /* Sanity checks */
            if (param < inter && buffer[i + param] >= 0x3c)
            {
                /* Private sequence, only parse what we know */
                debug("ansi import: private sequence \"^[[%.*s\"",
                      final - param + 1, buffer + i + param);
                continue;       /* Private sequence, skip it entirely */
            }

            if (final - param > 100)
                continue;       /* Suspiciously long sequence, skip it */

            /* Parse parameter bytes as per ECMA-48 5.4.2: Parameter string
               format */
            if (param < inter)
            {
                argv[0] = 0;
                for (j = param; j < inter; j++)
                {
                    if (buffer[i + j] == ';')
                        argv[++argc] = 0;
                    else if (buffer[i + j] >= '0' && buffer[i + j] <= '9')
                        argv[argc] = 10 * argv[argc] + (buffer[i + j] - '0');
                }
                argc++;
            }

            /* Interpret final byte. The code representations are given in
               ECMA-48 5.4: Control sequences, and the code definitions are
               given in ECMA-48 8.3: Definition of control functions. */
            debug("ansi import: command '%c'", buffer[i + final]);
            switch (buffer[i + final])
            {
            case 'A':          /* CUU (0x41) - Cursor Up */
                y -= argc ? argv[0] : 1;
                if (y < 0)
                    y = 0;
                break;
            case 'B':          /* CUD (0x42) - Cursor Down */
                y += argc ? argv[0] : 1;
                break;
            case 'C':          /* CUF (0x43) - Cursor Right */
                x += argc ? argv[0] : 1;
                break;
            case 'D':          /* CUB (0x44) - Cursor Left */
                x -= argc ? argv[0] : 1;
                if (x < 0)
                    x = 0;
                break;
            case 'G':          /* CHA (0x47) - Cursor Character Absolute */
                x = (argc && argv[0] > 0) ? argv[0] - 1 : 0;
                break;
            case 'H':          /* CUP (0x48) - Cursor Position */
                x = (argc > 1 && argv[1] > 0) ? argv[1] - 1 : 0;
                y = (argc > 0 && argv[0] > 0) ? argv[0] - 1 : 0;
                debug("ansi CUP : Cursor at %dx%d\n", x, y);
                break;
            case 'J':          /* ED (0x4a) - Erase In Page */
                savedattr = caca_get_attr(sc->cv, -1, -1);
                caca_set_attr(sc->cv, sc->clearattr);
                if (!argc || argv[0] == 0)
                {
                    caca_draw_line(sc->cv, x, y, width, y, ' ');
                    caca_fill_box(sc->cv, 0, y + 1, width, height - 1, ' ');
                }
                else if (argv[0] == 1)
                {
                    caca_fill_box(sc->cv, 0, 0, width, y, ' ');
                    caca_draw_line(sc->cv, 0, y, x, y, ' ');
                }
                else if (argv[0] == 2)
                {
                    // x = y = 0;
                    caca_fill_box(sc->cv, 0, 0, width, height, ' ');
                }
                caca_set_attr(sc->cv, savedattr);
                break;
            case 'K':          /* EL (0x4b) - Erase In Line */
                debug("ansi EL : cursor at %dx%d\n", x, y);
                if (!argc || argv[0] == 0)
                {
                    caca_draw_line(sc->cv, x, y, width, y, ' ');
                }
                else if (argv[0] == 1)
                {
                    caca_draw_line(sc->cv, 0, y, x, y, ' ');
                }
                else if (argv[0] == 2)
                {
                    caca_draw_line(sc->cv, 0, y, width, y, ' ');
                }
                break;
            case 'L':          /* IL - Insert line */
                {
                    unsigned int nb_lines = argc ? argv[0] : 1;
                    for (j = bottom - 1; j >= (unsigned int)y + nb_lines; j--)
                    {
                        for (k = 0; k < width; k++)
                        {
                            caca_put_char(sc->cv, k, j,
                                          caca_get_char(sc->cv, k,
                                                        j - nb_lines));
                            caca_put_attr(sc->cv, k, j,
                                          caca_get_attr(sc->cv, k,
                                                        j - nb_lines));
                        }
                        caca_draw_line(sc->cv, 0, j - nb_lines, width,
                                       j - nb_lines, ' ');
                    }
                }
                break;
            case 'P':          /* DCH (0x50) - Delete Character */
                if (!argc || argv[0] == 0)
                    argv[0] = 1;        /* echo -ne 'foobar\r\e[0P\n' */
                /* Jylam : Start from x, not 0 */
                for (j = x; (unsigned int)(j + argv[0]) < width; j++)
                {
                    caca_put_char(sc->cv, j, y,
                                  caca_get_char(sc->cv, j + argv[0], y));
                    caca_put_attr(sc->cv, j, y,
                                  caca_get_attr(sc->cv, j + argv[0], y));
                }
                break;          /* Jylam: this one was missing I guess */
#if 0
                savedattr = caca_get_attr(sc->cv, -1, -1);
                caca_set_attr(sc->cv, sc->clearattr);
                for (; (unsigned int)j < width; j++)
                    caca_put_char(sc->cv, j, y, ' ');
                caca_set_attr(sc->cv, savedattr);
#endif
            case 'X':          /* ECH (0x58) - Erase Character */
                if (argc && argv[0])
                {
                    savedattr = caca_get_attr(sc->cv, -1, -1);
                    caca_set_attr(sc->cv, sc->clearattr);
                    caca_draw_line(sc->cv, x, y, x + argv[0] - 1, y, ' ');
                    caca_set_attr(sc->cv, savedattr);
                }
            case 'c':          /* DA -- Device Attributes */
                    /* 
                     0 Base VT100, no options 
                     1 Processor options (STP) 
                     2 Advanced video option (AVO) 
                     3 AVO and STP 
                     4 Graphics processor option (GPO) 
                     5 GPO and STP 
                     6 GPO and AVO 
                     7 GPO, STP, and AVO 
                     */
                    /* Warning, argument is Pn */
                debug("ansi Got command c, argc %d, argv[0] (%d)\n", argc, argv[0], argv[0]);
                if (!argc || argv[0] == 0)
                {
                    send_ansi_sequence(screen_list, "\x1b[?1;0c");
                }
                else 
                {
                    switch (argv[0])
                    {
                    case 1:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x1c");
                        break;
                    case 2:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x2c");
                        break;
                    case 3:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x3c");
                        break;
                    case 4:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x4c");
                        break;
                    case 5:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x5c");
                        break;
                    case 6:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x6c");
                        break;
                    case 7:
                        send_ansi_sequence(screen_list, "\x1b[?\x1;\x7c");
                        break;
                        default:
                            debug("Unsupported DA option '%d'\n", argv[0]);
                            break;
                    }
                }
                break;
            case 'd':          /* VPA (0x64) - Line Position Absolute */
                y = (argc && argv[0] > 0) ? argv[0] - 1 : 0;
                break;
            case 'f':          /* HVP (0x66) - Character And Line Position */
                x = (argc > 1 && argv[1] > 0) ? argv[1] - 1 : 0;
                y = (argc > 0 && argv[0] > 0) ? argv[0] - 1 : 0;
                break;
            case 'g':          /* TBC -- Tabulation Clear */
                   
                if(argc==0 || argv[0] == 0) 
                {
                        x = (x - 7) & ~7;
                    if(x<0) x = 0;
                }
                break;
            case 'r':          /* FIXME */
                if (argc == 2)  /* DCSTBM - Set top and bottom margin */
                {
                    debug("DCSTBM %d %d", argv[0], argv[1]);
                    top = argv[0];
                    bottom = argv[1];
                }
                else
                    debug("ansi import: command r with %d params", argc);
                break;
            case 'h':          /* SM (0x68) - FIXME */
                debug("ansi import: set mode %i", argc ? (int)argv[0] : -1);
                break;
            case 'l':          /* RM (0x6c) - FIXME */
                debug("ansi import: reset mode %i", argc ? (int)argv[0] : -1);
                break;
            case 'm':          /* SGR (0x6d) - Select Graphic Rendition */
                if (argc)
                    ansi_parse_grcm(sc, argc, argv);
                else
                    ansi_parse_grcm(sc, 1, &dummy);
                break;
            case 'n':
                    debug("ansi command n, argc %d, argv[0] %d\n", argc, argv[0]);
                    if(!argc) break;
                    
                    switch(argv[0])
                    {
                        case 5:
                        /* Term ok */
                        send_ansi_sequence(screen_list, "\x1b[0n"); 
                        break;
                    case 6:
                        /* Cursor Position */
                        sprintf(b, "\x1b[%d;%dR", 
                                y+1,
                                x+1);
                        send_ansi_sequence(screen_list, b); 
                        break;
                    }
                    
                break;
            case 's':          /* Private (save cursor position) */
                save_x = x;
                save_y = y;
                break;
            case 'u':          /* Private (reload cursor position) */
                x = save_x;
                y = save_y;
                break;
            default:
                debug("ansi import: unknown command \"^[%.*s\"",
                      final - param + 1, buffer + i + param);
                break;
            }
        }

        /* Parse OSC stuff. */
        else if (buffer[i] == '\033' && buffer[i + 1] == ']')
        {
            char *string;
            unsigned int command = 0;
            unsigned int mode = 2, semicolon, final;

            for (semicolon = mode; i + semicolon < size; semicolon++)
            {
                if (buffer[i + semicolon] < '0' || buffer[i + semicolon] > '9')
                    break;
                command = 10 * command + (buffer[i + semicolon] - '0');
            }

            if (i + semicolon >= size || buffer[i + semicolon] != ';')
                break;          /* Invalid Mode */

            for (final = semicolon + 1; i + final < size; final++)
                if (buffer[i + final] < 0x20)
                    break;

            if (i + final >= size || buffer[i + final] != '\a')
                break;          /* Not enough data or no bell found */
            /* FIXME: XTerm also reacts to <ESC><backslash> and <ST> */
            /* FIXME: differenciate between not enough data (try again) and
               invalid data (print shit) */

            skip += final;

            string = malloc(final - (semicolon + 1) + 1);
            memcpy(string, buffer + i + (semicolon + 1),
                   final - (semicolon + 1));
            string[final - (semicolon + 1)] = '\0';
            debug("ansi import: got OSC command %i string '%s'", command,
                  string);
            if (command == 0 || command == 2)
            {
                if (sc->title)
                    free(sc->title);
                sc->title = string;
            }
            else
                free(string);
        }

        /* Get the character we’re going to paste */
        else
        {
            size_t bytes;

            if (i + 6 < size)
            {
                ch = caca_utf8_to_utf32((char const *)(buffer + i), &bytes);
            }
            else
            {
                /* Add a trailing zero to what we're going to read */
                char tmp[7];
                memcpy(tmp, buffer + i, size - i);
                tmp[size - i] = '\0';
                ch = caca_utf8_to_utf32(tmp, &bytes);
            }

            if (!bytes)
            {
                /* If the Unicode is invalid, assume it was latin1. */
                ch = buffer[i];
                bytes = 1;
            }

            /* very incomplete ISO-2022 implementation tailored to DEC ACS */
            if (sc->conv_state.cs == '@')
            {
                if (((ch > ' ') && (ch <= '~'))
                    &&
                    (sc->conv_state.
                     gn[sc->conv_state.ss ? sc->conv_state.
                        gn[sc->conv_state.ss] : sc->conv_state.glr[0]] == '0'))
                {
                    ch = dec_acs(ch);
                }
                else if (((ch > 0x80) && (ch < 0xff))
                         && (sc->conv_state.gn[sc->conv_state.glr[1]] == '0'))
                {
                    ch = dec_acs(ch + ' ' - 0x80);
                }
            }
            sc->conv_state.ss = 0;      /* no single-shift (GL) */

            wch = caca_utf32_is_fullwidth(ch) ? 2 : 1;

            skip += bytes - 1;
        }

        /* Wrap long lines or grow horizontally */
        while ((unsigned int)x + wch > width)
        {
            x -= width;
            y++;
        }

        /* Scroll or grow vertically */
        if ((unsigned int)y >= bottom)
        {
            int lines = (y - bottom) + 1;

            savedattr = caca_get_attr(sc->cv, -1, -1);

            for (j = top - 1; j + lines < bottom; j++)
            {
                for (k = 0; k < width; k++)
                {
                    caca_put_char(sc->cv, k, j,
                                  caca_get_char(sc->cv, k, j + lines));
                    caca_put_attr(sc->cv, k, j,
                                  caca_get_attr(sc->cv, k, j + lines));
                }
            }
            caca_set_attr(sc->cv, sc->clearattr);
            caca_fill_box(sc->cv, 0, bottom - lines, width, bottom - 1, ' ');
            y -= lines;
            caca_set_attr(sc->cv, savedattr);
        }

        /* Now paste our character, if any */
        if (wch)
        {
            caca_put_char(sc->cv, x, y, ch);
            x += wch;
        }
    }

    caca_gotoxy(sc->cv, x, y);

    if (i)
        sc->changed = 1;
    return i;
}

/* Coding Method Delimiter (CMD), ECMA-48 (1991), ISO/IEC 6429:1992 (ISO IR
   189) */

static void reset_conv_state(struct screen *sc)
{
    sc->conv_state.cs = '@';    /* ISO-2022 coding system */
    sc->conv_state.cn[0] = '@'; /* ISO 646 C0 control charset */
    sc->conv_state.cn[1] = 'C'; /* ISO 6429-1983 C1 control charset */
    sc->conv_state.glr[0] = 0;  /* G0 in GL */
    sc->conv_state.glr[1] = 2;  /* G2 in GR */
    sc->conv_state.gn[0] = 'B'; /* US-ASCII G0 charset */
    sc->conv_state.gn[1] = '0'; /* DEC ACS G1 charset */
    sc->conv_state.gn[2] = LITERAL2CHAR('.', 'A');      /* ISO 8859-1 G2
                                                           charset */
    sc->conv_state.gn[3] = LITERAL2CHAR('.', 'A');      /* ISO 8859-1 G3
                                                           charset */
    sc->conv_state.ss = 0;      /* no single-shift (GL) */
    sc->conv_state.ctrl8bit = 1;
}

/* XXX : ANSI loader helper */

static void ansi_parse_grcm(struct screen *sc,
                            unsigned int argc, unsigned int const *argv)
{
    static uint8_t const ansi2caca[] = {
        CACA_BLACK, CACA_RED, CACA_GREEN, CACA_BROWN,
        CACA_BLUE, CACA_MAGENTA, CACA_CYAN, CACA_LIGHTGRAY
    };

    unsigned int j;
    uint8_t efg, ebg;           /* Effective (libcaca) fg/bg */

    for (j = 0; j < argc; j++)
    {
        /* Defined in ECMA-48 8.3.117: SGR - SELECT GRAPHIC RENDITION */
        if (argv[j] >= 30 && argv[j] <= 37)
            sc->fg = ansi2caca[argv[j] - 30];
        else if (argv[j] >= 40 && argv[j] <= 47)
            sc->bg = ansi2caca[argv[j] - 40];
        else if (argv[j] >= 90 && argv[j] <= 97)
            sc->fg = ansi2caca[argv[j] - 90] + 8;
        else if (argv[j] >= 100 && argv[j] <= 107)
            sc->bg = ansi2caca[argv[j] - 100] + 8;
        else
            switch (argv[j])
            {
            case 0:            /* default rendition */
                sc->fg = sc->dfg;
                sc->bg = sc->dbg;
                sc->bold = sc->blink = sc->italics = sc->negative
                    = sc->concealed = sc->underline = sc->faint = sc->strike
                    = sc->proportional = 0;
                break;
            case 1:            /* bold or increased intensity */
                sc->bold = 1;
                break;
            case 2:            /* faint, decreased intensity or second colour 
                                 */
                sc->faint = 1;
                break;
            case 3:            /* italicized */
                sc->italics = 1;
                break;
            case 4:            /* singly underlined */
                sc->underline = 1;
                break;
            case 5:            /* slowly blinking (less then 150 per minute) */
            case 6:            /* rapidly blinking (150 per minute or more) */
                sc->blink = 1;
                break;
            case 7:            /* negative image */
                sc->negative = 1;
                break;
            case 8:            /* concealed characters */
                sc->concealed = 1;
                break;
            case 9:            /* crossed-out (characters still legible but
                                   marked as to be deleted */
                sc->strike = 1;
                break;
            case 21:           /* doubly underlined */
                sc->underline = 1;
                break;
            case 22:           /* normal colour or normal intensity (neither
                                   bold nor faint) */
                sc->bold = sc->faint = 0;
                break;
            case 23:           /* not italicized, not fraktur */
                sc->italics = 0;
                break;
            case 24:           /* not underlined (neither singly nor doubly) */
                sc->underline = 0;
                break;
            case 25:           /* steady (not blinking) */
                sc->blink = 0;
                break;
            case 26:           /* (reserved for proportional spacing as
                                   specified in CCITT Recommendation T.61) */
                sc->proportional = 1;
                break;
            case 27:           /* positive image */
                sc->negative = 0;
                break;
            case 28:           /* revealed characters */
                sc->concealed = 0;
                break;
            case 29:           /* not crossed out */
                sc->strike = 0;
                break;
            case 38:           /* (reserved for future standardization,
                                   intended for setting character foreground
                                   colour as specified in ISO 8613-6 [CCITT
                                   Recommendation T.416]) */
                break;
            case 39:           /* default display colour
                                   (implementation-defined) */
                sc->fg = sc->dfg;
                break;
            case 48:           /* (reserved for future standardization,
                                   intended for setting character background
                                   colour as specified in ISO 8613-6 [CCITT
                                   Recommendation T.416]) */
                break;
            case 49:           /* default background colour
                                   (implementation-defined) */
                sc->bg = sc->dbg;
                break;
            case 50:           /* (reserved for cancelling the effect of the
                                   rendering aspect established by parameter
                                   value 26) */
                sc->proportional = 0;
                break;
            default:
                debug("ansi import: unknown sgr %i", argv[j]);
                break;
            }
    }

    if (sc->concealed)
    {
        efg = ebg = CACA_TRANSPARENT;
    }
    else
    {
        efg = sc->negative ? sc->bg : sc->fg;
        ebg = sc->negative ? sc->fg : sc->bg;

        if (sc->bold)
        {
            if (efg < 8)
                efg += 8;
            else if (efg == CACA_DEFAULT)
                efg = CACA_WHITE;
        }
    }

    caca_set_color_ansi(sc->cv, efg, ebg);
}

int create_pty(char *cmd, unsigned int w, unsigned int h, int *cpid)
{
    char **argv;
    int fd;
    pid_t pid;

    pid = forkpty(&fd, NULL, NULL, NULL);
    if (pid < 0)
    {
        fprintf(stderr, "forkpty() error\n");
        return -1;
    }
    else if (pid == 0)
    {
        set_tty_size(0, w, h);
        putenv("CACA_DRIVER=slang");
        putenv("TERM=xterm");
        argv = malloc(2 * sizeof(char *));
        if (!argv)
        {
            fprintf(stderr, "Can't allocate memory at %s:%d\n", __FUNCTION__,
                    __LINE__);
            return -1;
        }
        argv[0] = cmd;
        argv[1] = NULL;
        execvp(cmd, argv);
        fprintf(stderr, "execvp() error\n");
        return -1;
    }

    *cpid = pid;

    fcntl(fd, F_SETFL, O_NDELAY);
    return fd;
}

int create_pty_grab(long pid, unsigned int w, unsigned int h, int *newpid)
{
    int fdm, fds;

    int ret = openpty(&fdm, &fds, NULL, NULL, NULL);

    if (ret < 0)
    {
        fprintf(stderr, "open() error\n");
        return -1;
    }

    set_tty_size(0, w, h);
    grab_process(pid, ptsname(fdm), fds, newpid);

    fcntl(fdm, F_SETFL, O_NDELAY);
    return fdm;
}

int set_tty_size(int fd, unsigned int w, unsigned int h)
{
    struct winsize ws;

    memset(&ws, 0, sizeof(ws));
    ws.ws_row = h;
    ws.ws_col = w;
    ioctl(fd, TIOCSWINSZ, (char *)&ws);

    return 0;
}



int update_terms(struct screen_list *screen_list)
{
    int i, refresh = 0;
    for (i = 0; i < screen_list->count; i++)
    {
        if (screen_list->screen[i]->total && !screen_list->dont_update_coords)
        {
            unsigned long int bytes;

            bytes = import_term(screen_list,
                                screen_list->screen[i],
                                screen_list->screen[i]->buf,
                                screen_list->screen[i]->total);

            if (bytes > 0)
            {
                screen_list->screen[i]->total -= bytes;
                memmove(screen_list->screen[i]->buf,
                        screen_list->screen[i]->buf + bytes,
                        screen_list->screen[i]->total);
                if (screen_list->screen[i]->visible || screen_list->mini)
                    refresh = 1;
            }
        }
    }
    return refresh;
}