output.c

/*
 * Copyright (C) 1984-2022  Mark Nudelman
 *
 * You may distribute under the terms of either the GNU General Public
 * License or the Less License, as specified in the README file.
 *
 * For more information, see the README file.
 */


/*
 * High level routines dealing with the output to the screen.
 */

#include "less.h"
#if MSDOS_COMPILER==WIN32C
#include "windows.h"
#ifndef COMMON_LVB_UNDERSCORE
#define COMMON_LVB_UNDERSCORE 0x8000
#endif
#endif

public int errmsgs;    /* Count of messages displayed by error() */
public int need_clr;
public int final_attr;
public int at_prompt;

extern int sigs;
extern int sc_width;
extern int so_s_width, so_e_width;
extern int screen_trashed;
extern int is_tty;
extern int oldbot;

#if MSDOS_COMPILER==WIN32C || MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
extern int ctldisp;
extern int nm_fg_color, nm_bg_color;
extern int bo_fg_color, bo_bg_color;
extern int ul_fg_color, ul_bg_color;
extern int so_fg_color, so_bg_color;
extern int bl_fg_color, bl_bg_color;
extern int sgr_mode;
#if MSDOS_COMPILER==WIN32C || MSDOS_COMPILER==DJGPPC
extern int vt_enabled;
#endif
#endif

/*
 * Display the line which is in the line buffer.
 */
    public void
put_line(VOID_PARAM)
{
    int c;
    int i;
    int a;

    if (ABORT_SIGS())
    {
        /*
         * Don't output if a signal is pending.
         */
        screen_trashed = 1;
        return;
    }

    final_attr = AT_NORMAL;

    for (i = 0;  (c = gline(i, &a)) != '\0';  i++)
    {
        at_switch(a);
        final_attr = a;
        if (c == '\b')
            putbs();
        else
            putchr(c);
    }

    at_exit();
}

static char obuf[OUTBUF_SIZE];
static char *ob = obuf;
static int outfd = 2; /* stderr */

#if MSDOS_COMPILER==WIN32C || MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
    static void
win_flush(VOID_PARAM)
{
    if (ctldisp != OPT_ONPLUS || (vt_enabled && sgr_mode))
        WIN32textout(obuf, ob - obuf);
    else
    {
        /*
         * Look for SGR escape sequences, and convert them
         * to color commands.  Replace bold, underline,
         * and italic escapes into colors specified via
         * the -D command-line option.
         */
        char *anchor, *p, *p_next;
        static int fg, fgi, bg, bgi;
        static int at;
        int f, b;
#if MSDOS_COMPILER==WIN32C
        /* Screen colors used by 3x and 4x SGR commands. */
        static unsigned char screen_color[] = {
            0, /* BLACK */
            FOREGROUND_RED,
            FOREGROUND_GREEN,
            FOREGROUND_RED|FOREGROUND_GREEN,
            FOREGROUND_BLUE,
            FOREGROUND_BLUE|FOREGROUND_RED,
            FOREGROUND_BLUE|FOREGROUND_GREEN,
            FOREGROUND_BLUE|FOREGROUND_GREEN|FOREGROUND_RED
        };
#else
        static enum COLORS screen_color[] = {
            BLACK, RED, GREEN, BROWN,
            BLUE, MAGENTA, CYAN, LIGHTGRAY
        };
#endif

        if (fg == 0 && bg == 0)
        {
            fg  = nm_fg_color & 7;
            fgi = nm_fg_color & 8;
            bg  = nm_bg_color & 7;
            bgi = nm_bg_color & 8;
        }
        for (anchor = p_next = obuf;
             (p_next = memchr(p_next, ESC, ob - p_next)) != NULL; )
        {
            p = p_next;
            if (p[1] == '[')  /* "ESC-[" sequence */
            {
                if (p > anchor)
                {
                    /*
                     * If some chars seen since
                     * the last escape sequence,
                     * write them out to the screen.
                     */
                    WIN32textout(anchor, p-anchor);
                    anchor = p;
                }
                p += 2;  /* Skip the "ESC-[" */
                if (is_ansi_end(*p))
                {
                    /*
                     * Handle null escape sequence
                     * "ESC[m", which restores
                     * the normal color.
                     */
                    p++;
                    anchor = p_next = p;
                    fg  = nm_fg_color & 7;
                    fgi = nm_fg_color & 8;
                    bg  = nm_bg_color & 7;
                    bgi = nm_bg_color & 8;
                    at  = 0;
                    WIN32setcolors(nm_fg_color, nm_bg_color);
                    continue;
                }
                p_next = p;
                at &= ~32;

                /*
                 * Select foreground/background colors
                 * based on the escape sequence.
                 */
                while (!is_ansi_end(*p))
                {
                    char *q;
                    long code = strtol(p, &q, 10);

                    if (*q == '\0')
                    {
                        /*
                         * Incomplete sequence.
                         * Leave it unprocessed
                         * in the buffer.
                         */
                        int slop = (int) (q - anchor);
                        /* {{ strcpy args overlap! }} */
                        strcpy(obuf, anchor);
                        ob = &obuf[slop];
                        return;
                    }

                    if (q == p ||
                        code > 49 || code < 0 ||
                        (!is_ansi_end(*q) && *q != ';'))
                    {
                        p_next = q;
                        break;
                    }
                    if (*q == ';')
                    {
                        q++;
                        at |= 32;
                    }

                    switch (code)
                    {
                    default:
                    /* case 0: all attrs off */
                        fg = nm_fg_color & 7;
                        bg = nm_bg_color & 7;
                        at &= 32;
                        /*
                         * \e[0m use normal
                         * intensities, but
                         * \e[0;...m resets them
                         */
                        if (at & 32)
                        {
                            fgi = 0;
                            bgi = 0;
                        } else
                        {
                            fgi = nm_fg_color & 8;
                            bgi = nm_bg_color & 8;
                        }
                        break;
                    case 1: /* bold on */
                        fgi = 8;
                        at |= 1;
                        break;
                    case 3: /* italic on */
                    case 7: /* inverse on */
                        at |= 2;
                        break;
                    case 4: /* underline on */
                        bgi = 8;
                        at |= 4;
                        break;
                    case 5: /* slow blink on */
                    case 6: /* fast blink on */
                        bgi = 8;
                        at |= 8;
                        break;
                    case 8: /* concealed on */
                        at |= 16;
                        break;
                    case 22: /* bold off */
                        fgi = 0;
                        at &= ~1;
                        break;
                    case 23: /* italic off */
                    case 27: /* inverse off */
                        at &= ~2;
                        break;
                    case 24: /* underline off */
                        bgi = 0;
                        at &= ~4;
                        break;
                    case 28: /* concealed off */
                        at &= ~16;
                        break;
                    case 30: case 31: case 32:
                    case 33: case 34: case 35:
                    case 36: case 37:
                        fg = screen_color[code - 30];
                        at |= 32;
                        break;
                    case 39: /* default fg */
                        fg = nm_fg_color & 7;
                        at |= 32;
                        break;
                    case 40: case 41: case 42:
                    case 43: case 44: case 45:
                    case 46: case 47:
                        bg = screen_color[code - 40];
                        at |= 32;
                        break;
                    case 49: /* default bg */
                        bg = nm_bg_color & 7;
                        at |= 32;
                        break;
                    }
                    p = q;
                }
                if (!is_ansi_end(*p) || p == p_next)
                    break;
                /*
                 * In SGR mode, the ANSI sequence is
                 * always honored; otherwise if an attr
                 * is used by itself ("\e[1m" versus
                 * "\e[1;33m", for example), set the
                 * color assigned to that attribute.
                 */
                if (sgr_mode || (at & 32))
                {
                    if (at & 2)
                    {
                        f = bg | bgi;
                        b = fg | fgi;
                    } else
                    {
                        f = fg | fgi;
                        b = bg | bgi;
                    }
                } else
                {
                    if (at & 1)
                    {
                        f = bo_fg_color;
                        b = bo_bg_color;
                    } else if (at & 2)
                    {
                        f = so_fg_color;
                        b = so_bg_color;
                    } else if (at & 4)
                    {
                        f = ul_fg_color;
                        b = ul_bg_color;
                    } else if (at & 8)
                    {
                        f = bl_fg_color;
                        b = bl_bg_color;
                    } else
                    {
                        f = nm_fg_color;
                        b = nm_bg_color;
                    }
                }
                if (at & 16)
                    f = b ^ 8;
#if MSDOS_COMPILER==WIN32C
                f &= 0xf | COMMON_LVB_UNDERSCORE;
#else
                f &= 0xf;
#endif
                b &= 0xf;
                WIN32setcolors(f, b);
                p_next = anchor = p + 1;
            } else
                p_next++;
        }

        /* Output what's left in the buffer.  */
        WIN32textout(anchor, ob - anchor);
    }
    ob = obuf;
}
#endif

/*
 * Flush buffered output.
 *
 * If we haven't displayed any file data yet,
 * output messages on error output (file descriptor 2),
 * otherwise output on standard output (file descriptor 1).
 *
 * This has the desirable effect of producing all
 * error messages on error output if standard output
 * is directed to a file.  It also does the same if
 * we never produce any real output; for example, if
 * the input file(s) cannot be opened.  If we do
 * eventually produce output, code in edit() makes
 * sure these messages can be seen before they are
 * overwritten or scrolled away.
 */
    public void
flush(VOID_PARAM)
{
    int n;

    n = (int) (ob - obuf);
    if (n == 0)
        return;
    ob = obuf;

#if MSDOS_COMPILER==MSOFTC
    if (interactive())
    {
        obuf[n] = '\0';
        _outtext(obuf);
        return;
    }
#else
#if MSDOS_COMPILER==WIN32C || MSDOS_COMPILER==BORLANDC || MSDOS_COMPILER==DJGPPC
    if (interactive())
    {
        ob = obuf + n;
        *ob = '\0';
        win_flush();
        return;
    }
#endif
#endif

    if (write(outfd, obuf, n) != n)
        screen_trashed = 1;
}

/*
 * Set the output file descriptor (1=stdout or 2=stderr).
 */
    public void
set_output(fd)
    int fd;
{
    flush();
    outfd = fd;
}


/*
 * Output a character.
 */
    public int
putchr(c)
    int c;
{
#if 0 /* fake UTF-8 output for testing */
    extern int utf_mode;
    if (utf_mode)
    {
        static char ubuf[MAX_UTF_CHAR_LEN];
        static int ubuf_len = 0;
        static int ubuf_index = 0;
        if (ubuf_len == 0)
        {
            ubuf_len = utf_len(c);
            ubuf_index = 0;
        }
        ubuf[ubuf_index++] = c;
        if (ubuf_index < ubuf_len)
            return c;
        c = get_wchar(ubuf) & 0xFF;
        ubuf_len = 0;
    }
#endif
    clear_bot_if_needed();
#if MSDOS_COMPILER
    if (c == '\n' && is_tty)
    {
        /* remove_top(1); */
        putchr('\r');
    }
#else
#ifdef _OSK
    if (c == '\n' && is_tty)  /* In OS-9, '\n' == 0x0D */
        putchr(0x0A);
#endif
#endif
    /*
     * Some versions of flush() write to *ob, so we must flush
     * when we are still one char from the end of obuf.
     */
    if (ob >= &obuf[sizeof(obuf)-1])
        flush();
    *ob++ = c;
    at_prompt = 0;
    return (c);
}

    public void
clear_bot_if_needed(VOID_PARAM)
{
    if (!need_clr)
        return;
    need_clr = 0;
    clear_bot();
}

/*
 * Output a string.
 */
    public void
putstr(s)
    constant char *s;
{
    while (*s != '\0')
        putchr(*s++);
}


/*
 * Convert an integral type to a string.
 */
#define TYPE_TO_A_FUNC(funcname, type) \
void funcname(num, buf) \
    type num; \
    char *buf; \
{ \
    int neg = (num < 0); \
    char tbuf[INT_STRLEN_BOUND(num)+2]; \
    char *s = tbuf + sizeof(tbuf); \
    if (neg) num = -num; \
    *--s = '\0'; \
    do { \
        *--s = (num % 10) + '0'; \
    } while ((num /= 10) != 0); \
    if (neg) *--s = '-'; \
    strcpy(buf, s); \
}

TYPE_TO_A_FUNC(postoa, POSITION)
TYPE_TO_A_FUNC(linenumtoa, LINENUM)
TYPE_TO_A_FUNC(inttoa, int)

/*
 * Convert an string to an integral type.
 */
#define STR_TO_TYPE_FUNC(funcname, type) \
type funcname(buf, ebuf) \
    char *buf; \
    char **ebuf; \
{ \
    type val = 0; \
    for (;; buf++) { \
        char c = *buf; \
        if (c < '0' || c > '9') break; \
        val = 10 * val + c - '0'; \
    } \
    if (ebuf != NULL) *ebuf = buf; \
    return val; \
}

STR_TO_TYPE_FUNC(lstrtopos, POSITION)
STR_TO_TYPE_FUNC(lstrtoi, int)

/*
 * Output an integer in a given radix.
 */
    static int
iprint_int(num)
    int num;
{
    char buf[INT_STRLEN_BOUND(num)];

    inttoa(num, buf);
    putstr(buf);
    return ((int) strlen(buf));
}

/*
 * Output a line number in a given radix.
 */
    static int
iprint_linenum(num)
    LINENUM num;
{
    char buf[INT_STRLEN_BOUND(num)];

    linenumtoa(num, buf);
    putstr(buf);
    return ((int) strlen(buf));
}

/*
 * This function implements printf-like functionality
 * using a more portable argument list mechanism than printf's.
 *
 * {{ This paranoia about the portability of printf dates from experiences
 *    with systems in the 1980s and is of course no longer necessary. }}
 */
    public int
less_printf(fmt, parg)
    char *fmt;
    PARG *parg;
{
    char *s;
    int col;

    col = 0;
    while (*fmt != '\0')
    {
        if (*fmt != '%')
        {
            putchr(*fmt++);
            col++;
        } else
        {
            ++fmt;
            switch (*fmt++)
            {
            case 's':
                s = parg->p_string;
                parg++;
                while (*s != '\0')
                {
                    putchr(*s++);
                    col++;
                }
                break;
            case 'd':
                col += iprint_int(parg->p_int);
                parg++;
                break;
            case 'n':
                col += iprint_linenum(parg->p_linenum);
                parg++;
                break;
            case 'c':
                s = prchar(parg->p_char);
                parg++;
                while (*s != '\0')
                {
                    putchr(*s++);
                    col++;
                }
                break;
            case '%':
                putchr('%');
                break;
            }
        }
    }
    return (col);
}

/*
 * Get a RETURN.
 * If some other non-trivial char is pressed, unget it, so it will
 * become the next command.
 */
    public void
get_return(VOID_PARAM)
{
    int c;

#if ONLY_RETURN
    while ((c = getchr()) != '\n' && c != '\r')
        bell();
#else
    c = getchr();
    if (c != '\n' && c != '\r' && c != ' ' && c != READ_INTR)
        ungetcc(c);
#endif
}

/*
 * Output a message in the lower left corner of the screen
 * and wait for carriage return.
 */
    public void
error(fmt, parg)
    char *fmt;
    PARG *parg;
{
    int col = 0;
    static char return_to_continue[] = "  (press RETURN)";

    errmsgs++;

    if (!interactive())
    {
        less_printf(fmt, parg);
        putchr('\n');
        return;
    }

    if (!oldbot)
        squish_check();
    at_exit();
    clear_bot();
    at_enter(AT_STANDOUT|AT_COLOR_ERROR);
    col += so_s_width;
    col += less_printf(fmt, parg);
    putstr(return_to_continue);
    at_exit();
    col += sizeof(return_to_continue) + so_e_width;

    get_return();
    lower_left();
    clear_eol();

    if (col >= sc_width)
        /*
         * Printing the message has probably scrolled the screen.
         * {{ Unless the terminal doesn't have auto margins,
         *    in which case we just hammered on the right margin. }}
         */
        screen_trashed = 1;

    flush();
}

static char intr_to_abort[] = "... (interrupt to abort)";

/*
 * Output a message in the lower left corner of the screen
 * and don't wait for carriage return.
 * Usually used to warn that we are beginning a potentially
 * time-consuming operation.
 */
    public void
ierror(fmt, parg)
    char *fmt;
    PARG *parg;
{
    at_exit();
    clear_bot();
    at_enter(AT_STANDOUT|AT_COLOR_ERROR);
    (void) less_printf(fmt, parg);
    putstr(intr_to_abort);
    at_exit();
    flush();
    need_clr = 1;
}

/*
 * Output a message in the lower left corner of the screen
 * and return a single-character response.
 */
    public int
query(fmt, parg)
    char *fmt;
    PARG *parg;
{
    int c;
    int col = 0;

    if (interactive())
        clear_bot();

    (void) less_printf(fmt, parg);
    c = getchr();

    if (interactive())
    {
        lower_left();
        if (col >= sc_width)
            screen_trashed = 1;
        flush();
    } else
    {
        putchr('\n');
    }

    if (c == 'Q')
        quit(QUIT_OK);
    return (c);
}