path: root/mbbsd/pmore.c

/* $Id$ */
#include "bbs.h"

/*
 * "pmore" is "piaip's more", NOT "PTT's more"!!!
 *
 * piaip's new implementation of pager(more) with mmap,
 * designed for unlimilited length(lines).
 *
 * Author: Hung-Te Lin (piaip), June 2005.
 * <piaip@csie.ntu.edu.tw>
 *
 * MAJOR IMPROVEMENTS:
 *  - Clean source code, and more readble to mortal
 *  - Correct navigation
 *  - Excellent search ability (for correctness and user behavior)
 *  - Less memory consumption (mmap is not considered)
 *  - Better support for large terminals
 *  - Unlimited file length and line numbers
 *
 * TODO:
 *  - Speed up with supporting Scroll [done]
 *  - Support PTT_PRINTS [done]
 *  - Wrap long lines or left-right wide navigation
 *  - Big5 truncation
 * 
 * WONTDO:
 *  - The message seperator line is different from old more.
 *    I decided to abandon the old style (which is buggy).
 *    > old   style: increase one line to show seperator
 *    > pmore style: use blank line for seperator.
 *
 * HINTS:
 *  - Remember mmap pointers are NOT null terminated strings.
 *    You have to use strn* APIs and make sure not exceeding mmap buffer.
 *    DO NOT USE strcmp, strstr, strchr, ...
 *  - Scroll handling is painful. If you displayed anything on screen,
 *    remember to MFDISP_DIRTY();
 *  - To be portable between most BBS systems, pmore is designed to
 *    workaround most BBS bugs inside itself.
 */

#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <ctype.h>
#include <string.h>

// Platform Related. NoSync is faster but if we don't have it...
#ifdef MAP_NOSYNC
#define MF_MMAP_OPTION (MAP_NOSYNC)
#else
#define MF_MMAP_OPTION (MAP_SHARED)
#endif

// --------------------------------------------------------------- <FEATURES>
#define PMORE_USE_PTT_PRINTS
#define PMORE_USE_SCROLL
#define PMORE_PRELOAD_SIZE (512*1024L) // on busy system set smaller or undef
// -------------------------------------------------------------- </FEATURES>

#define DEBUG
int debug = 0;

// --------------------------------------------- <Defines and constants>

// --------------------------- <Display>
// Escapes. I don't like \033 everywhere.
#define ESC_NUM (0x1b)
#define ESC_STR "\x1b"
#define ESC_CHR '\x1b'

// Common ANSI commands.
#define ANSI_RESET  (ESC_STR "[m")
#define ANSI_COLOR(x) ESC_STR "[" #x "m"

// Poor BBS terminal system Workarounds
// - Most BBS implements clrtoeol() as fake command
//   and usually messed up when output ANSI quoted string.
// - A workaround is suggested by kcwu:
//   https://opensvn.csie.org/traccgi/pttbbs/trac.cgi/changeset/519
#define FORCE_CLRTOEOL() outs(ESC_STR "[K");
// --------------------------- </Display>

// --------------------------- <Main Navigation>
typedef struct
{
    unsigned char 
    rawmode,    // show file as-is.
    *start, *end,   // file buffer
    *disps, *dispe, // disply start/end
    *maxdisps;  // a very special pointer, 
                //   consider as "disps of last page"
    off_t len;      // file total length
    long  lineno,   // lineno of disps
      oldlineno,    // last drawn lineno, < 0 means full update
      maxlinenoS;   // lineno of maxdisps, "S"! 
                // NOT REAL MAX LINENO NOR FILELENGTH!!!
} MmappedFile;

MmappedFile mf = { 
    0, 0, 0, 0, 0, 0, 
    0, 0, -1L, -1L 
};  // current file

/* mf_* navigation commands and return value meanings */
enum {
    MFNAV_OK,       // navigation ok
    MFNAV_EXCEED,   // request exceeds buffer
} MF_NAV_COMMANDS;

// Navigation units (dynamic, so not in enum const)
#define MFNAV_PAGE  (t_lines-2) // when navigation, how many lines in a page to move
#define MFDISP_PAGE (t_lines-1) // for display, the real number of lines to be shown.
#define MFDISP_DIRTY() { mf.oldlineno = -1; }
// --------------------------- </Main Navigation>

// --------------------------- <Aux. Structures>
/* pretty format header */
typedef struct
{
    int lines;  // header lines
    int authorlen;
    int boardlen;
} ArticleHeader;

ArticleHeader ah;

/* search records */
typedef struct
{
    int  len;
    int (*cmpfunc) (const char *, const char *, size_t);
    char search_str[81];    // maybe we can change to dynamic allocation
} SearchRecord;

SearchRecord sr = { 0, strncmp, "" };

enum {
    MFSEARCH_FORWARD,
    MFSEARCH_BACKWARD,
} MFSEARCH_DIRECTION;

// Reset structures
#define RESETMF() { memset(&mf, 0, sizeof(mf)); \
    mf.maxlinenoS = mf.oldlineno = -1; }
#define RESETAH() { memset(&ah, 0, sizeof(ah)); \
    ah.lines = ah.authorlen= ah.boardlen = -1; }
// --------------------------- </Aux. Structures>

// --------------------------------------------- </Defines and constants>


int mf_backward(int);   // used by mf_attach
void mf_sync_lineno();  // used by mf_attach

/* 
 * mmap basic operations 
 */
int mf_attach(unsigned char *fn)
{
    struct stat st;
    int fd = open(fn, O_RDONLY, 0600);

    if(fd < 0)
    return 0;

    if (fstat(fd, &st) || ((mf.len = st.st_size) <= 0) || S_ISDIR(st.st_mode))
    {
    mf.len = 0;
    close(fd);
    return 0;
    }

    /*
    mf.len = lseek(fd, 0L, SEEK_END);
    lseek(fd, 0, SEEK_SET);
    */

    mf.start = mmap(NULL, mf.len, PROT_READ, 
        MF_MMAP_OPTION, fd, 0);
    close(fd);

    if(mf.start == MAP_FAILED)
    {
    RESETMF();
    return 0;
    }

    mf.end = mf.start + mf.len;
    mf.disps = mf.dispe = mf.start;
    mf.lineno = 0;

    // build maxdisps
    mf.disps = mf.end - 1;
    mf_backward(MFNAV_PAGE);
    mf.maxdisps = mf.disps;

#ifdef PMORE_PRELOAD_SIZE
    if(mf.len <= PMORE_PRELOAD_SIZE)
    mf_sync_lineno(); // maxlinenoS will be automatically updated
    else
#endif
    mf.maxlinenoS = -1;

    mf.disps = mf.dispe = mf.start;
    mf.lineno = 0;
    return  1;
}

void mf_detach()
{
    if(mf.start) {
    munmap(mf.start, mf.len);
    RESETMF();
    }
}

/*
 * lineno calculation, and moving
 */
void mf_sync_lineno()
{
    unsigned char *p;

    if(mf.disps == mf.maxdisps && mf.maxlinenoS >= 0)
    {
    mf.lineno = mf.maxlinenoS;
    } else {
    mf.lineno = 0;
    for (p = mf.start; p < mf.disps; p++)
        if(*p == '\n')
        mf.lineno ++;

    if(mf.disps == mf.maxdisps && mf.maxlinenoS < 0)
        mf.maxlinenoS = mf.lineno;
    }
}

int mf_backward(int lines)
{
    int flFirstLine = 1;
    // first, because we have to trace back to line beginning,
    // add one line.
    lines ++;

    // now try to rollback for lines
    if(lines == 1)
    {
    /* special case! just rollback to start */
    while ( mf.disps > mf.start && 
        *(mf.disps-1) != '\n')
        mf.disps --;
    mf.disps --;
    lines --;
    }
    else while(mf.disps > mf.start && lines > 0)
    {
    while (mf.disps > mf.start && *--mf.disps != '\n');
    if(flFirstLine)
    {
        flFirstLine = 0; lines--;
        continue;
    }

    if(mf.disps >= mf.start) 
        mf.lineno--, lines--;
    }

    if(mf.disps == mf.start)
    mf.lineno = 0;
    else
    mf.disps ++;

    if(lines > 0)
    return MFNAV_OK;
    else
    return MFNAV_EXCEED;
}

int mf_forward(int lines)
{
    while(mf.disps <= mf.maxdisps && lines > 0)
    {
    while (mf.disps <= mf.maxdisps && *mf.disps++ != '\n');

    if(mf.disps <= mf.maxdisps)
        mf.lineno++, lines--;
    }

    if(mf.disps > mf.maxdisps)
    mf.disps = mf.maxdisps;

    /* please make sure you have lineno synced. */
    if(mf.disps == mf.maxdisps && mf.maxlinenoS < 0)
    mf.maxlinenoS = mf.lineno;

    if(lines > 0)
    return MFNAV_OK;
    else
    return MFNAV_EXCEED;
}

int mf_goTop()
{
    mf.disps = mf.start;
    mf.lineno = 0;
    return MFNAV_OK;
}

int mf_goBottom()
{
    mf.disps = mf.maxdisps;
    /*
    mf.disps = mf.end-1;
    mf_backward(MFNAV_PAGE);
    */
    mf_sync_lineno();

    return MFNAV_OK;
}

int mf_goto(int lineno)
{
    mf.disps = mf.start;
    mf.lineno = 0;
    return mf_forward(lineno);
}

int mf_viewedNone()
{
    return (mf.disps <= mf.start);
}

int mf_viewedAll()
{
    return (mf.dispe >= mf.end);
}
/*
 * search!
 */
int mf_search(int direction)
{
    unsigned char *s = sr.search_str;
    int l = sr.len;
    int flFound = 0;

    if(!*s)
    return 0;

    if(direction ==  MFSEARCH_FORWARD) 
    {
    mf_forward(1);
    while(mf.disps < mf.end - l)
    {
        if(sr.cmpfunc(mf.disps, s, l) == 0)
        {
        flFound = 1;
        break;
        } else
        mf.disps ++;
    }
    mf_backward(0);
    if(mf.disps > mf.maxdisps)
        mf.disps = mf.maxdisps;
    mf_sync_lineno();
    } 
    else if(direction ==  MFSEARCH_BACKWARD) 
    {
    mf_backward(1);
    while (!flFound && mf.disps > mf.start)
    {
        while(!flFound && mf.disps < mf.end-l && *mf.disps != '\n')
        {
        if(sr.cmpfunc(mf.disps, s, l) == 0)
        {
            flFound = 1;
        } else
            mf.disps ++;
        }
        if(!flFound)
        mf_backward(1);
    }
    mf_backward(0);
    if(mf.disps < mf.start)
        mf.disps = mf.start;
    mf_sync_lineno();
    }
    if(flFound)
    MFDISP_DIRTY();
    return flFound;
}

/*
 * Format Related
 */
void mf_parseHeader()
{
    /* format:
     * AUTHOR: author BOARD: blah
     * XXX: xxx
     * XXX: xxx
     * [blank, fill with seperator]
     *
     * #define STR_AUTHOR1     "作者:"
     * #define STR_AUTHOR2     "發信人:"
     * #define STR_POST1       "看板:"
     * #define STR_POST2       "站內:"
     */
    RESETAH();
    if(mf.len > LEN_AUTHOR2)
    {
    if (strncmp(mf.start, STR_AUTHOR1, LEN_AUTHOR1) == 0)
    {
        ah.lines = 3;   // local
        ah.authorlen = LEN_AUTHOR1;
    } 
    else if (strncmp(mf.start, STR_AUTHOR2, LEN_AUTHOR2) == 0)
    {
        ah.lines = 4;
        ah.authorlen = LEN_AUTHOR2;
    }
    /* traverse for author length */
    {
        unsigned char *p = mf.start;
        unsigned char *pb = p;

        /* first, go to line-end */
        while(p < mf.end && *p != '\n')
        p++;
        pb = p;
        /* next, rollback for ':' */
        while(p > mf.start && *p != ':')
        p--;
        if(p > mf.start && *p == ':')
        {
        ah.boardlen = pb - p;
        while (p > mf.start && *p != ' ')
            p--;
        if( *p == ' ')
        {
            ah.authorlen = p - mf.start - ah.authorlen;
        } else
            ah.boardlen = -1, ah.authorlen = -1;
        } else
        ah.authorlen = -1;
    }
    }
}

/*
 * display mf content from disps for MFDISP_PAGE
 */
#define STR_ANSICODE    "[0123456789;,"
#define DISP_HEADS_LEN (4)  // strlen of each heads
static const char *disp_heads[] = {"作者", "標題", "時間", "轉信"};

void mf_disp()
{
    int lines = 0, col = 0, currline = 0;
    int startline = 0, endline = MFDISP_PAGE-1;
    // int x_min = 0;
    int x_max = t_columns - 1;
    int header_w = (t_columns - 1 - (t_columns-1)%2);
    /*
     * it seems like that BBS scroll has some bug
     * if we scroll a fulfilled buffer, so leave one space.
     */

#ifdef PMORE_USE_SCROLL
    /* process scrolling */
    if (mf.oldlineno >= 0 && mf.oldlineno != mf.lineno)
    {
    int scrll = mf.lineno - mf.oldlineno, i;
    int reverse = (scrll > 0 ? 0 : 1);

    if(reverse) 
        scrll = -scrll;
    else
    {
        /* because bottom status line is also scrolled,
         * we have to erase it here.
         */
        move(b_lines, 0);
        clrtoeol();
    }

    if(scrll > MFDISP_PAGE)
        scrll = MFDISP_PAGE;

    i = scrll;
    while(i-- > 0)
        if (reverse)
        rscroll();  // v
        else
        scroll();   // ^

    if(reverse)
    {
        startline = 0;  // v
        endline = scrll-1;
        // clear the line which will be scrolled
        // to bottom (status line position).
        move(b_lines, 0);
        clrtoeol();
    }
    else
    {
        startline = MFDISP_PAGE - scrll; // ^
        endline   = MFDISP_PAGE - 1;
    }
    move(startline, 0);
    // return;  // uncomment if you want to observe scrolling
    }
    else
#endif
    clear(), move(0, 0);

    mf.dispe = mf.disps;
    while (lines < MFDISP_PAGE) 
    {
    int inAnsi = 0;
    int skip = 0;

    currline = mf.lineno + lines;
    col = 0;
    
    /* Is currentline visible? */
    if (lines < startline || lines > endline)
    {
        while(mf.dispe < mf.end && *mf.dispe != '\n')
        mf.dispe++;
        skip = 1;   /* prevent printing trailing '\n' */
    }
    /* Now, consider what kind of line
     * (header, seperator, or normal text)
     * is current line.
     */
    else if (!mf.rawmode && currline == ah.lines)
    {
        /* case 1, header seperator line */
        outs(ANSI_COLOR(36));
        for(col = 0; col < header_w; col+=2)
        {
        // prints("%02d", col);
        outs("─");
        }
        outs(ANSI_RESET);
        while(mf.dispe < mf.end && *mf.dispe != '\n')
        mf.dispe++;
        col = x_max-1;
    } 
    else if (!mf.rawmode && currline < ah.lines)
    {
        /* case 2, we're printing headers */
        int w = t_columns, i_author = 0;
        int flDrawBoard = 0, flDrawAuthor = 0;
        const char *ph = disp_heads[currline];

        if (currline == 0 && ah.boardlen > 0)
        flDrawAuthor = 1;
draw_header:
        if(flDrawAuthor)
        w = header_w - ah.boardlen - 6;
        else
        w = header_w;

        outs(ANSI_COLOR(47;34) " "); col++;

        /* special case for STR_AUTHOR2 */
        if(!flDrawBoard)
        {
        outs(ph);
        col += DISP_HEADS_LEN;  // strlen(disp_heads[currline])
        } else {
        /* display as-is */
        while (*mf.dispe != ':' && *mf.dispe != '\n')
        if(col++ <= header_w)
            outc(*mf.dispe++);
        }

        while (*mf.dispe != ':' && *mf.dispe != '\n')
        mf.dispe ++;

        if(*mf.dispe == ':') {
        outs(" " ANSI_COLOR(44;37)); 
        col++;
        mf.dispe ++;
        }

        while (col < w) {   // -2 to match seperator
        int flCanDraw = (*mf.dispe != '\n');

        if(flDrawAuthor)
            flCanDraw = i_author < ah.authorlen;
        if(flCanDraw)
        {
            /* strip ansi in headers */
            unsigned char c = *mf.dispe++;
            if(inAnsi)
            {
            if (!strchr(STR_ANSICODE, c))
                inAnsi = 0;
            } else {
            if(c == ESC_CHR)
                inAnsi = 1;
            else
                outc(c), col++, i_author++;
            }
        } else {
            outc(' '), col++;
        }
        }

        if (flDrawAuthor)
        {
        flDrawBoard = 1;
        flDrawAuthor = 0;
        while(*mf.dispe == ' ')
            mf.dispe ++;
        goto draw_header;
        }

        outs(ANSI_RESET);
        // skip to end of line
        while(mf.dispe < mf.end && *mf.dispe != '\n')
        mf.dispe++;
        col = x_max-1;
    } 
    else if(mf.dispe < mf.end)
    {
        /* case 3, normal text */
        long dist = mf.end - mf.dispe;
        long flResetColor = 0;
        int  srlen = -1;

        // first check quote
        if(!mf.rawmode)
        {
        if(dist > 1 && 
            (*mf.dispe == ':' || *mf.dispe == '>') && 
            *(mf.dispe+1) == ' ')
        {
            outs(ANSI_COLOR(36));
            flResetColor = 1;
        } else if (dist > 2 && 
            (!strncmp(mf.dispe, "※", 2) || 
             !strncmp(mf.dispe, "==>", 3)))
        {
            outs(ANSI_COLOR(32));
            flResetColor = 1;
        }
        }

        while(mf.dispe < mf.end && *mf.dispe != '\n')
        {
        if(inAnsi)
        {
            if (!strchr(STR_ANSICODE, *mf.dispe))
            inAnsi = 0;
            if(col <= x_max)
            outc(*mf.dispe);
        } else {
            if(*mf.dispe == ESC_CHR)
            inAnsi = 1;
            else if(srlen < 0 && sr.search_str[0] && // support search
                //tolower(sr.search_str[0]) == tolower(*mf.dispe) &&
                mf.end - mf.dispe > sr.len &&
                sr.cmpfunc(mf.dispe, sr.search_str, sr.len) == 0)
            {
                outs(ANSI_COLOR(7)); 
                srlen = sr.len-1;
                flResetColor = 1;
            }

#ifdef PMORE_USE_PTT_PRINTS
            /* special case to resolve dirty Ptt_Prints */
            if(inAnsi && 
                mf.end - mf.dispe > 2 &&
                *(mf.dispe+1) == '*')
            {
            int i;
            char buf[64];   // make sure ptt_prints will not exceed

            memset(buf, 0, sizeof(buf));
            strncpy(buf, mf.dispe, 3);  // ^[[*s
            mf.dispe += 2;

            Ptt_prints(buf, NO_RELOAD); // result in buf
            i = strlen(buf);

            if (col + i > x_max)
                i = x_max - col;
            if(i > 0)
            {
                buf[i] = 0;
                col += i;
                outs(buf);
            }
            inAnsi = 0;
            } else
#endif
            {
            if(col <= x_max)
                outc(*mf.dispe);
            if(!inAnsi)
            {
                col++;
                if (srlen == 0)
                outs(ANSI_RESET);
                if(srlen >= 0)
                srlen --;
            }
            }
        }
        mf.dispe ++;
        }
        if(flResetColor)
        outs(ANSI_RESET);
    }

    if(mf.dispe < mf.end) 
        mf.dispe ++;

    if(!skip)
    {
        if(col < x_max) /* can we do so? */
        {
        FORCE_CLRTOEOL();
        outc('\n');
        }
        else
        // outc('>'),
        move(lines+1, 0);
    }
    lines ++;
    }
    mf.oldlineno = mf.lineno;
}

/* --------------------- MAIN PROCEDURE ------------------------- */

static const char    * const pmore_help[] = {
    "\0閱\讀文章功\能鍵使用說明",
    "\01游標移動功\能鍵",
    "(j)(↑)               上捲一行",
    "(k)(↓)(Enter)        下捲一行",
    "(^B)(PgUp)(BackSpace) 上捲一頁",
    "(→)(PgDn)(Space)     下捲一頁",
    "(0)(g)(Home)          檔案開頭",
    "($)(G)(End)           檔案結尾",
    "(;/:)                 跳至某行/某頁",
    "數字鍵 1-9            跳至輸入的行號",
    "\01其他功\能鍵",
    "(/)                   搜尋字串",
    "(n/N)                 重複正/反向搜尋",
    "(Ctrl-T)              存到暫存檔",
    "(f/b)                 跳至下/上篇",
    "(a/A)                 跳至同一作者下/上篇",
    "(t/[-/]+)             主題式閱\讀:循序/前/後篇",
    "(\\)                   切換顯示原始內容",  // this IS already aligned!
    "(q)(←)               結束",
    "(h)(H)(?)             本說明畫面",
#ifdef DEBUG
    "(d)                   切換除錯(debug)模式",
#endif
    "\01本系統使用 piaip 的新式瀏覽程式",
    NULL
};

/*
 * piaip's more, a replacement for old more
 */
int pmore(char *fpath, int promptend)
{
    int  flExit = 0, retval = 0;
    int  ch = 0;

    STATINC(STAT_MORE);
    if(!mf_attach(fpath))
    return -1;

    /* reset and parse article header */
    mf_parseHeader();

    clear();
    while(!flExit)
    {
    mf_disp();

    if(promptend == NA && mf_viewedAll())
        break;

    move(b_lines, 0);
    // clrtoeol(); // this shall be done in mf_disp to speed up.

    /* PRINT BOTTOM STATUS BAR */
    if(debug)
    prints("L#%d pmt=%d Dsp:%08X/%08X/%08X, F:%08X/%08X(%d) tScr(%dx%d)",
        (int)mf.lineno, 
        promptend,
        (unsigned int)mf.disps, 
        (unsigned int)mf.maxdisps,
        (unsigned int)mf.dispe,
        (unsigned int)mf.start, (unsigned int)mf.end,
        (int)mf.len,
        t_columns,
        t_lines
        );
    else
    {
        char *printcolor;
        char buf[256];  // orz
        int prefixlen = 0;
        int barlen = 0;
        int postfixlen = 0;

        if(mf_viewedAll())
        printcolor = ANSI_COLOR(37;44);
        else if (mf_viewedNone())
        printcolor = ANSI_COLOR(34;46);
        else
        printcolor = ANSI_COLOR(33;45);

        outs(ANSI_RESET);
        outs(printcolor);
        if(mf.maxlinenoS >= 0)
        sprintf(buf,
            "  瀏覽 第 %1d/%1d 頁 ",
            (int)(mf.lineno / MFNAV_PAGE)+1,
            (int)(mf.maxlinenoS / MFNAV_PAGE)+1
               );
        else
        sprintf(buf,
            "  瀏覽 第 %1d 頁 ",
            (int)(mf.lineno / MFNAV_PAGE)+1
               );
        outs(buf); prefixlen += strlen(buf);

        outs(ANSI_COLOR(1;30;47));

        sprintf(buf,
            " 閱\讀進度%3d%%, 目前顯示: 第 %02d~%02d 行 ",
            (int)((unsigned long)(mf.dispe-mf.start) * 100 / mf.len),
            (int)(mf.lineno + 1),
            (int)(mf.lineno + MFDISP_PAGE)
           );

        outs(buf); prefixlen += strlen(buf);

#define TRAILINGMSGLEN (23)  // trailing msg columns
        postfixlen = TRAILINGMSGLEN;

        if (prefixlen + postfixlen + 1 > t_columns)
        postfixlen = 0;
        barlen = t_columns - 1 - postfixlen - prefixlen;

        while(barlen-- > 0)
        outc(' ');

        if(postfixlen > 0)  /* enough buffer */
        outs(
            ANSI_COLOR(0;31;47) "(h)" 
            ANSI_COLOR(30) "按鍵說明 "
            ANSI_COLOR(31) "←[q]" 
            ANSI_COLOR(30) "離開  "
            );
        outs(ANSI_RESET);
        FORCE_CLRTOEOL();
    }

    /* igetch() will do refresh(); */
    ch = igetch();
    switch (ch) {
        /* ------------------ EXITING KEYS ------------------ */
        case 'r':
        case 'R':
        case 'Y':
        case 'y':
        flExit = 1, retval = 999;
        break;
        case 'X':
        flExit = 1, retval = 998;
        break;
        case 'A':
        flExit = 1, retval = AUTHOR_PREV;
        break;
        case 'a':
        flExit = 1, retval = AUTHOR_NEXT;
        break;
        case 'F':
        case 'f':
        flExit = 1, retval = READ_NEXT;
        break;
        case 'B':
        case 'b':
        flExit = 1, retval = READ_PREV;
        break;
        case KEY_LEFT:
        case 'q':
        flExit = 1, retval = FULLUPDATE;
        break;

        /* from Kaede, thread reading */
        case ']':
        case '+':
        flExit = 1, retval = RELATE_NEXT;
        break;
        case '[':
        case '-':
        flExit = 1, retval = RELATE_PREV;
        break;
        case '=':
        flExit = 1, retval = RELATE_FIRST;
        break;
        /* ------------------ NAVIGATION KEYS ------------------ */
        /* Simple Navigation */
        case 'j':
        case 'J':
        mf_backward(1);
        break;
        case 'k':
        case 'K':
        mf_forward(1);
        break;

        case Ctrl('F'):
        case KEY_PGDN:
        mf_forward(MFNAV_PAGE);
        break;
        case Ctrl('B'):
        case KEY_PGUP:
        mf_backward(MFNAV_PAGE);
        break;

        case '0':
        case 'g':
        case KEY_HOME:
        mf_goTop();
        break;
        case '$':
        case 'G':
        case KEY_END:
        mf_goBottom();
        break;

        /* Compound Navigation */
        case '\r':
        case '\n':
        case KEY_DOWN:
        if (mf_viewedAll() ||
            (promptend == 2 && (ch == '\r' || ch == '\n')))
            flExit = 1, retval = READ_NEXT;
        else
            mf_forward(1);
        break;

        case ' ':
        if (mf_viewedAll())
            flExit = 1, retval = READ_NEXT;
        else
            mf_forward(MFNAV_PAGE);
        break;
        case KEY_RIGHT:
        if(mf_viewedAll())
            promptend = 0, flExit = 1, retval = 0;
        else
            mf_forward(MFNAV_PAGE);
        break;

        case KEY_UP:
        if(mf_viewedNone())
            flExit = 1, retval = READ_PREV;
        else
            mf_backward(1);
        break;
        case Ctrl('H'):
        if(mf_viewedNone())
            flExit = 1, retval = READ_PREV;
        else
            mf_backward(MFNAV_PAGE);
        break;

        case 't':
        if (mf_viewedAll())
            flExit = 1, retval = RELATE_NEXT;
        else
            mf_forward(MFNAV_PAGE);
        break;
        /* ------------------ SEARCH  KEYS ------------------ */
        case '/':
        {
            char ans[4] = "n";

            sr.search_str[0] = 0;
            getdata_buf(b_lines - 1, 0, "[搜尋]關鍵字:", sr.search_str,
                40, DOECHO);
            if (sr.search_str[0]) {
            if (getdata(b_lines - 1, 0, "區分大小寫(Y/N/Q)? [N] ",
                    ans, sizeof(ans), LCECHO) && *ans == 'y')
                sr.cmpfunc = strncmp;
            else
                sr.cmpfunc = strncasecmp;
            if (*ans == 'q')
                sr.search_str[0] = 0;
            }
            sr.len = strlen(sr.search_str);
            mf_search(MFSEARCH_FORWARD);
            MFDISP_DIRTY();
        }
        break;
        case 'n':
        mf_search(MFSEARCH_FORWARD);
        break;
        case 'N':
        mf_search(MFSEARCH_BACKWARD);
        break;
        /* ------------------ SPECIAL KEYS ------------------ */
        case '1': case '2': case '3': case '4': case '5':
        case '6': case '7': case '8': case '9':
        case ';': case ':':
        {
            char buf[10] = "";
            int  i = 0;
            int  pageMode = (ch == ':');
            if (ch >= '1' && ch <= '9')
            buf[0] = ch, buf[1] = 0;

            getdata_buf(b_lines-1, 0, 
                (pageMode ? "跳至此頁: " : "跳至此行: "),
                buf, 7, DOECHO);
            if(buf[0]) {
            i = atoi(buf);
            if(i-- > 0)
                mf_goto(i * (pageMode ? MFNAV_PAGE : 1));
            }
            MFDISP_DIRTY();
        }
        break;

        case Ctrl('T'):
        {
            char buf[10];
            getdata(b_lines - 1, 0, "把這篇文章收入到暫存檔？[y/N] ",
                buf, 4, LCECHO);
            if (buf[0] == 'y') {
            setuserfile(buf, ask_tmpbuf(b_lines - 1));
                        Copy(fpath, buf);
            }
            MFDISP_DIRTY();
        }
        break;

        case 'h':
        case 'H':
        case '?':
        // help
        show_help(pmore_help);
        MFDISP_DIRTY();
        break;

        case 'E':
        // admin edit any files other than ve help file
        if (HAS_PERM(PERM_SYSOP) && strcmp(fpath, "etc/ve.hlp")) {
            mf_detach();
            vedit(fpath, NA, NULL);
            return 0;
        }
        break;
        case '\\':
        mf.rawmode = !mf.rawmode;
        MFDISP_DIRTY();
        break;
#ifdef DEBUG
        case 'd':
        debug = !debug;
        MFDISP_DIRTY();
        break;
#endif
    }
    }

    mf_detach();
    if (retval == 0 && promptend) {
    pressanykey();
    clear();
    } else
    outs(reset_color);

    return retval;
}

/* vim:sw=4
 */