path: root/mbbsd/pmore.c

/* $Id$ */

/*
 * pmore: piaip's more, a new replacement for traditional pager
 *
 * piaip's new implementation of pager(more) with mmap,
 * designed for unlimilited length(lines).
 *
 * "pmore" is "piaip's more", NOT "PTT's more"!!!
 * pmore is designed for general maple-family BBS systems, not 
 * specific to any branch.
 *
 * Author: Hung-Te Lin (piaip), June 2005.
 * <piaip@csie.ntu.edu.tw>
 * All Rights Reserved.
 * You are free to use, modify, redistribute this program 
 * in any BBS style systems, or any other non-commercial usage.
 * You must keep these copyright infomration.
 *
 * 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 anyway)
 *  - Better support for large terminals
 *  - Unlimited file length and line numbers
 *
 * TODO AND DONE:
 *  - Optimized speed up with Scroll supporting [done]
 *  - Support PTT_PRINTS [done]
 *  - Wrap long lines [done]
 *  - DBCS friendly wrap [done]
 *  - ASCII Art movie support [done]
 *  - Left-right wide navigation [done]
 *  - Reenrtance for main procedure [done with little hack]
 *  - A new optimized terminal base system (piterm) [dropped]
 *  - ASCII Art movie navigation keys [pending]
 *  - 
 *  - [2007, Movie Enhancement]
 *  - New Invisible Frame Header Code [done]
 *  - Traditional Movie Compatible Mode 
 *  - Playback Control (pause, stop, skip, loop)
 *  - Interactive Movie (Hyper-text)
 *  - Support Anti-anti-idle (ex, PCMan sends up-down)
 *  - Virtual Contatenate [pending]
 *  - Better help system
 *  - Configuration system (like I in boards)
 */

// --------------------------------------------------------------- <FEATURES>
/* These are default values.
 * You may override them in your bbs.h or config.h etc etc.
 */
#define PMORE_PRELOAD_SIZE (64*1024L)   // on busy system set smaller or undef

#define PMORE_USE_PTT_PRINTS        // support PTT or special printing
#define PMORE_USE_OPT_SCROLL        // optimized scroll
#define PMORE_USE_DBCS_WRAP     // safe wrap for DBCS.
#define PMORE_USE_ASCII_MOVIE       // support ascii movie
//#define PMORE_RESTRICT_ANSI_MOVEMENT  // user cannot use ANSI escapes to move
#define PMORE_WORKAROUND_CLRTOEOL   // try to work with poor terminal sys
#define PMORE_ACCURATE_WRAPEND      // try more harder to find file end in wrap mode
#define PMORE_LOG_SYSOP_EDIT        // log whenever sysop uses E

#define PMORE_TRADITIONAL_PROMPTEND // when prompt=NA, show only page 1
#define PMORE_TRADITIONAL_FULLCOL   // to work with traditional ascii arts
#define PMORE_OVERRIDE_TIME     // override time format if possible
// -------------------------------------------------------------- </FEATURES>

#include "bbs.h"

#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.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|MAP_SHARED)
#else
#define MF_MMAP_OPTION (MAP_SHARED)
#endif

/* Developer's Guide
 * 
 * OVERVIEW
 *  - pmore is designed as a line-oriented pager. After you load (mf_attach)
 *    a file, you can move current display window by lines (mf_forward and
 *    mf_backward) and then display a page(mf_display).
 *    And please remember to delete allocated resources (mf_detach)
 *    when you exit.
 *  - Functions are designed to work with global variables.
 *    However you can overcome re-entrance problem by backuping up variables
 *    or replace all "." to "->" with little modification and add pointer as
 *    argument passed to each function. 
 *    (This is really tested and it works, however then using global variables
 *    is considered to be faster and easier to maintain, at lease shorter in
 *    time to key-in and for filelength).
 *  - Basically this file should only export one function, "pmore".
 *    Using any other functions here may be dangerous because they are not
 *    coded for external reentrance rightnow.
 *  - mf_* are operation functions to work with file buffer.
 *    Usually these function assumes "mf" can be accessed.
 *  - pmore_* are utility functions
 *
 * DETAIL
 *  - The most tricky part of pmore is the design of "maxdisps" and "maxlinenoS".
 *    What do they mean? "The pointer and its line number of last page".
 *    - Because pmore is designed to work with very large files, it's costly to
 *      calculate the total line numbers (and not necessary).  But if we don't
 *      know about how many lines left can we display then when navigating by
 *      pages may result in a page with single line conent (if you set display
 *      starting pointer to the real last line).
 *    - To overcome this issue, maxdisps is introduced. It tries to go backward
 *      one page from end of file (this operation is lighter than visiting 
 *      entire file content for line number calculation). Then we can set this
 *      as boundary of forward navigation.
 *    - maxlinenoS is the line number of maxdisps. It's NOT the real number of
 *      total line in current file (You have to add the last page). That's why
 *      it has a strange name of trailing "S", to hint you that it's not 
 *      "maxlineno" which is easily considered as "max(total) line number".
 *
 * 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.
 *  - Basically pmore considered the 'outc' output system as unlimited buffer.
 *    However on most BBS implementation, outc used a buffer with ANSILINELEN
 *    in length. And for some branches they even used unsigned byte for index.
 *    So if user complained about output truncated or blanked, increase buffer.
 */

#ifdef DEBUG
int debug = 0;
# define MFPROTO
#else
# define MFPROTO inline static
#endif

/* DBCS users tend to write unsigned char. let's make compiler happy */
#define ustrlen(x)  strlen((char*)x)
#define ustrchr(x,y)    (unsigned char*)strchr((char*)x, y)
#define ustrrchr(x,y)   (unsigned char*)strrchr((char*)x, y)


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

// --------------------------- <Display>

/* ANSI COMMAND SYSTEM */
/* On some systems with pmore style ANSI system applied,
 * we don't have to define these again.
 */
#ifndef PMORE_STYLE_ANSI
#define PMORE_STYLE_ANSI

// 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"
#define ANSI_CLRTOEND   ESC_STR "[K"
#define ANSI_MOVETO(y,x) ESC_STR "[" #y ";" #x "H"

#define ANSI_IN_ESCAPE(x) (((x) >= '0' && (x) <= '9') || \
    (x) == ';' || (x) == ',' || (x) == '[')

#endif /* PMORE_STYLE_ANSI */

#define ANSI_IN_MOVECMD(x) (strchr("ABCDfjHJRu", x) != NULL)
#define PMORE_DBCS_LEADING(c) (c >= 0x80)

// 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(ANSI_CLRTOEND)

/* Again, if you have a BBS system which optimized out* without recognizing
 * ANSI escapes, scrolling with ANSI text may result in melformed text (because
 * ANSI escapes were "optimized" ). So here we provide a method to overcome
 * with this situation. However your should increase your I/O buffer to prevent
 * flickers.
 */
MFPROTO void 
pmore_clrtoeol(int y, int x)
{
#ifdef PMORE_WORKAROUND_CLRTOEOL
    int i; 
    move(y, x); 
    for (i = x; i < t_columns; i++) 
    outc(' '); 
    clrtoeol();
    move(y, x);
#else
    move(y, x);
    clrtoeol();
    move(y, x);
#endif
}

// --------------------------- </Display>

// --------------------------- <Main Navigation>
typedef struct
{
    unsigned char 
    *start, *end,   // file buffer
    *disps, *dispe, // displayed content 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
      xpos,     // starting x position
            //
      wraplines,    // wrapped lines in last display
      trunclines,   // truncated lines in last display
      dispedlines,  // how many different lines displayed
            //  usually dispedlines = PAGE-wraplines,
            //  but if last line is incomplete(wrapped),
            //  dispedlines = PAGE-wraplines + 1
      lastpagelines,// lines of last page to show
                    //  this indicates how many lines can
            //  maxdisps(maxlinenoS) display.
      maxlinenoS;   // lineno of maxdisps, "S"! 
            //  What does the magic "S" mean?
            //  Just trying to notify you that it's 
                //  NOT REAL MAX LINENO NOR FILELENGTH!!!
            //  You may consider "S" of "Start" (disps).
} MmappedFile;

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

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

/* Navigation units (dynamic, so not in enum const) */
#define MFNAV_PAGE  (t_lines-2) // when navigation, how many lines in a page to move

/* Display system */
enum MF_DISP_CONST {
    /* newline method (because of poor BBS implementation) */
    MFDISP_NEWLINE_CLEAR = 0, // \n and cleartoeol
    MFDISP_NEWLINE_SKIP,
    MFDISP_NEWLINE_MOVE,  // use move to simulate newline.

    MFDISP_WRAP_TRUNCATE = 0,
    MFDISP_WRAP_WRAP,

    MFDISP_OPT_CLEAR = 0,
    MFDISP_OPT_OPTIMIZED,
    MFDISP_OPT_FORCEDIRTY,

    MFDISP_SEP_NONE = 0x00,
    MFDISP_SEP_LINE = 0x01,
    MFDISP_SEP_WRAP = 0x02,
    MFDISP_SEP_OLD  = MFDISP_SEP_LINE | MFDISP_SEP_WRAP,

    MFDISP_RAW_NA   = 0x00,
    MFDISP_RAW_NOANSI,
    MFDISP_RAW_PLAIN,
    MFDISP_RAW_MODES,
    // MFDISP_RAW_NOFMT, // this is rarely used sinde we have ansi and plain

};

#define MFDISP_PAGE (t_lines-1) // the real number of lines to be shown.
#define MFDISP_DIRTY() { mf.oldlineno = -1; }

/* Indicators */
#define MFDISP_TRUNC_INDICATOR  ANSI_COLOR(0;1;37) ">" ANSI_RESET
#define MFDISP_WRAP_INDICATOR   ANSI_COLOR(0;1;37) "\\" ANSI_RESET
#define MFDISP_WNAV_INDICATOR   ANSI_COLOR(0;1;37) "<" ANSI_RESET
// --------------------------- </Main Navigation>

// --------------------------- <Aux. Structures>
/* browsing preference */
typedef struct
{
    /* mode flags */
    unsigned short int
    wrapmode,   // wrap?
    seperator,  // seperator style
        indicator,  // show wrap indicators

    oldwrapmode,    // traditional wrap
        oldstatusbar,   // traditional statusbar
    rawmode;    // show file as-is.
} MF_BrowsingPrefrence;

MF_BrowsingPrefrence bpref =
{ MFDISP_WRAP_WRAP, MFDISP_SEP_OLD, 1, 
    0, 0, 0, };

/* pretty format header */
#define FH_HEADERS    (4)  // how many headers do we know?
#define FH_HEADER_LEN (4)  // strlen of each heads
static const char *_fh_disp_heads[FH_HEADERS] = 
    {"作者", "標題", "時間", "轉信"};

typedef struct
{
    int lines;  // header lines
    unsigned char *headers[FH_HEADERS];
    unsigned char *floats[2];   // right floating, name and val
} MF_PrettyFormattedHeader;

MF_PrettyFormattedHeader fh = { 0, {0,0,0,0}, {0, 0}};

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

MF_SearchRecord sr = { 0, strncmp, NULL};

enum MFSEARCH_DIRECTION {
    MFSEARCH_FORWARD,
    MFSEARCH_BACKWARD,
};

// Reset structures
#define RESETMF() { memset(&mf, 0, sizeof(mf)); \
    mf.lastpagelines = mf.maxlinenoS = mf.oldlineno = -1; }
#define RESETFH() { memset(&fh, 0, sizeof(fh)); \
    fh.lines = -1; }

// --------------------------- </Aux. Structures>

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

// --------------------------------------------- <Optional Modules>
#ifdef PMORE_USE_ASCII_MOVIE
enum _MFDISP_MOVIE_MODES {
    MFDISP_MOVIE_UNKNOWN= 0,
    MFDISP_MOVIE_DETECTED,
    MFDISP_MOVIE_YES,
    MFDISP_MOVIE_NO,
    MFDISP_MOVIE_PLAYING,
    MFDISP_MOVIE_PLAYING_OLD,
};

typedef struct {
    struct timeval frameclk;
    struct timeval synctime;
    unsigned char *options,
          *optkeys;
    unsigned char  mode,
           compat24,
           interactive,
           pause;
} MF_Movie;

MF_Movie mfmovie;

#define STOP_MOVIE() {  \
    mfmovie.options = NULL; \
    mfmovie.pause    = 0; \
    if (mfmovie.mode == MFDISP_MOVIE_PLAYING) \
        mfmovie.mode =  MFDISP_MOVIE_YES; \
    if (mfmovie.mode == MFDISP_MOVIE_PLAYING_OLD) \
        mfmovie.mode =  MFDISP_MOVIE_NO; \
}

#define RESET_MOVIE() { \
    mfmovie.mode = MFDISP_MOVIE_UNKNOWN; \
    mfmovie.options = NULL; \
    mfmovie.optkeys = NULL; \
    mfmovie.compat24 = 1; \
    mfmovie.pause    = 0; \
    mfmovie.interactive     = 0; \
    mfmovie.synctime.tv_sec = mfmovie.synctime.tv_usec = 0; \
    mfmovie.frameclk.tv_sec = 1; mfmovie.frameclk.tv_usec = 0; \
}

unsigned char *
    mf_movieFrameHeader(unsigned char *p, unsigned char *end);

int pmore_wait_key(struct timeval *ptv, int dorefresh);
int mf_movieNextFrame();
int mf_movieSyncFrame();
int mf_moviePromptPlaying();
int mf_movieMaskedInput(int c);

void mf_float2tv(float f, struct timeval *ptv);

#define MOVIE_MIN_FRAMECLK (0.1f)
#define MOVIE_MAX_FRAMECLK (3600.0f)
#define MOVIE_SECOND_U (1000000L)
#define MOVIE_ANTI_ANTI_IDLE

#endif
// --------------------------------------------- </Optional Modules>

// used by mf_attach
void mf_parseHeaders();
void mf_freeHeaders();
void mf_determinemaxdisps(int, int);

/* 
 * mmap basic operations 
 */
int 
mf_attach(const 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;
    }

    // BSD mmap advise. comment if your OS does not support this.
    madvise(mf.start, mf.len, MADV_SEQUENTIAL);

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

    mf_determinemaxdisps(MFNAV_PAGE, 0);

    mf.disps = mf.dispe = mf.start;
    mf.lineno = 0;

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

    /* a workaround for wrapped seperators */
    if(mf.maxlinenoS > 0 &&
        fh.lines >= mf.maxlinenoS &&
        bpref.seperator & MFDISP_SEP_WRAP)
    {
    mf_determinemaxdisps(+1, 1);
    }

    return  1;
}

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

    }
    mf_freeHeaders();
}

/*
 * 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;
    }
}

MFPROTO int mf_backward(int); // used by mf_buildmaxdisps
MFPROTO int mf_forward(int); // used by mf_buildmaxdisps

void
mf_determinemaxdisps(int backlines, int update_by_offset)
{
    unsigned char *pbak = mf.disps, *mbak = mf.maxdisps;
    long lbak = mf.lineno;

    if(update_by_offset)
    {
    if(backlines > 0)
    {
        /* tricky way because usually 
         * mf_forward checks maxdisps.
         */
        mf.disps = mf.maxdisps;
        mf.maxdisps = mf.end-1;
        mf_forward(backlines);
        mf_backward(0);
    } else
        mf_backward(backlines);
    } else {
    mf.lineno = backlines;
    mf.disps = mf.end - 1;
    backlines = mf_backward(backlines);
    }

    if(mf.disps != mbak)
    {
    mf.maxdisps = mf.disps;
    if(update_by_offset)
        mf.lastpagelines -= backlines;
    else
        mf.lastpagelines = backlines;

    mf.maxlinenoS = -1;
#ifdef PMORE_PRELOAD_SIZE
    if(mf.len <= PMORE_PRELOAD_SIZE)
        mf_sync_lineno(); // maxlinenoS will be automatically updated
#endif
    }
    mf.disps = pbak;
    mf.lineno = lbak;
}

/*
 * mf_backwards is also used for maxno determination,
 * so we cannot change anything in mf except these:
 *   mf.disps
 *   mf.lineno
 */
MFPROTO int 
mf_backward(int lines)
{
    int real_moved = 0;

    /* backward n lines means to find n times of '\n'. */

    /* if we're already in a line break, add one mark. */
   if (mf.disps < mf.end && *mf.disps == '\n')
       lines++, real_moved --;

    while (1)
    {
    if (mf.disps < mf.start || *mf.disps == '\n')
    {
        real_moved ++;
        if(lines-- <= 0 || mf.disps < mf.start)
        break;
    }
    mf.disps --;
    }

    /* now disps points to previous 1 byte of new address */
    mf.disps ++;
    real_moved --;
    mf.lineno -= real_moved;

    return real_moved;
}

MFPROTO int 
mf_forward(int lines)
{
    int real_moved = 0;

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

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

    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;

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

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

int 
mf_goBottom()
{
    mf.disps = mf.maxdisps;
    mf_sync_lineno();

    return MFNAV_OK;
}

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

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

MFPROTO 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 || !*s)
    return 0;

    if(direction ==  MFSEARCH_FORWARD) 
    {
    mf_forward(1);
    while(mf.disps < mf.end - l)
    {
        if(sr.cmpfunc((char*)mf.disps, (char*)s, l) == 0)
        {
        flFound = 1;
        break;
        } else {
        /* DBCS check here. */
        if(PMORE_DBCS_LEADING(*mf.disps++))
            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((char*)mf.disps, (char*)s, l) == 0)
        {
            flFound = 1;
        } else
        {
            /* DBCS check here. */
            if(PMORE_DBCS_LEADING(*mf.disps++))
            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;
}

/* String Processing
 *
 * maybe you already have your string processors (or not).
 * whether yes or no, here we provides some.
 */

#define ISSPACE(x) (x <= ' ')

MFPROTO void 
pmore_str_strip_ansi(unsigned char *p)  // warning: p is NULL terminated
{
    unsigned char *pb = p;
    while (*p != 0)
    {
    if (*p == ESC_CHR)
    {
        // ansi code sequence, ignore them.
        pb = p++;
        while (ANSI_IN_ESCAPE(*p))
        p++;
        memmove(pb, p, ustrlen(p)+1);
        p = pb;
    }
    else if (*p < ' ' || *p == 0xff)
    {
        // control codes, ignore them.
        // what is 0xff? old BBS does not handle telnet protocol
        // so IACs were inserted.
        memmove(p, p+1, ustrlen(p+1)+1);
    }
    else
        p++;
    }
}

/* this chomp is a little different: 
 * it kills starting and trailing spaces.
 */
MFPROTO void 
pmore_str_chomp(unsigned char *p)
{
    unsigned char *pb = p + ustrlen(p)-1;

    while (pb >= p)
    if(ISSPACE(*pb))
        *pb-- = 0;
    else
        break;
    pb = p;
    while (*pb && ISSPACE(*pb))
    pb++;

    if(pb != p)
    memmove(p, pb, ustrlen(pb)+1);
}

#if 0
int 
pmore_str_safe_big5len(unsigned char *p)
{
    return 0;
}
#endif

/*
 * Format Related
 */

void 
mf_freeHeaders()
{
    if(fh.lines > 0)
    {
    int i;

    for (i = 0; i < FH_HEADERS; i++)
        if(fh.headers[i])
        free(fh.headers[i]);
    for (i = 0; i < sizeof(fh.floats) / sizeof(unsigned char*); i++)
        free(fh.floats[i]);
    RESETFH();
    }
}

void 
mf_parseHeaders()
{
    /* file format:
     * AUTHOR: author BOARD: blah <- headers[0], flaots[0], floats[1]
     * XXX: xxx           <- headers[1]
     * XXX: xxx           <- headers[n]
     * [blank, fill with seperator] <- lines
     *
     * #define STR_AUTHOR1     "作者:"
     * #define STR_AUTHOR2     "發信人:"
     */
    unsigned char *pmf = mf.start;
    int i = 0;

    RESETFH();

    if(mf.len < LEN_AUTHOR2)
    return;

    if (strncmp((char*)mf.start, STR_AUTHOR1, LEN_AUTHOR1) == 0)
    {
    fh.lines = 3;   // local
    } 
    else if (strncmp((char*)mf.start, STR_AUTHOR2, LEN_AUTHOR2) == 0)
    {
    fh.lines = 4;
    }
    else 
    return;

    for (i = 0; i < fh.lines; i++)
    {
    unsigned char *p = pmf, *pb = pmf;
    int l;

    /* first, go to line-end */
    while(pmf < mf.end && *pmf != '\n')
        pmf++;
    if(pmf >= mf.end)
        break;
    p = pmf;
    pmf ++; // move to next line.

    // p is pointing at a new line. (\n)
    l = (int)(p - pb);
#ifdef CRITICAL_MEMORY
    // kcwu: dirty hack, avoid 64byte slot. use 128byte slot instead.
    if (l<100) {
        p = (unsigned char*) malloc (100+1);
    } else {
        p = (unsigned char*) malloc (l+1);
    }
#else
    p = (unsigned char*) malloc (l+1);
#endif
    fh.headers[i] = p;
    memcpy(p, pb, l);
    p[l] = 0;

    // now, postprocess p.
    pmore_str_strip_ansi(p);

#ifdef PMORE_OVERRIDE_TIME
    // (deprecated: too many formats for newsgroup)
    // try to see if this is a valid time line
    // use strptime to convert
#endif // PMORE_OVERRIDE_TIME

    // strip to quotes[+1 space]
    if((pb = ustrchr((char*)p, ':')) != NULL)
    {
        if(*(pb+1) == ' ') pb++;
        memmove(p, pb, ustrlen(pb)+1);
    }

    // kill staring and trailing spaces
    pmore_str_chomp(p);

    // special case, floats are in line[0].
    if(i == 0 && (pb = ustrrchr(p, ':')) != NULL && *(pb+1))
    {
        unsigned char *np = (unsigned char*)strdup((char*)(pb+1));

        fh.floats[1] = np;
        pmore_str_chomp(np);
        // remove quote and traverse back
        *pb-- = 0;
        while (pb > p && *pb != ',' && !(ISSPACE(*pb)))
        pb--;

        if (pb > p) {
        fh.floats[0] = (unsigned char*)strdup((char*)(pb+1));
        pmore_str_chomp(fh.floats[0]);
        *pb = 0;
        pmore_str_chomp(fh.headers[0]);
        } else {
        fh.floats[0] = (unsigned char*)strdup("");
        }
    }
    }
}

/*
 * mf_display utility macros
 */
MFPROTO void
MFDISP_SKIPCURLINE()
{ 
    while (mf.dispe < mf.end && *mf.dispe != '\n')
    mf.dispe++;
}

MFPROTO int
MFDISP_PREDICT_LINEWIDTH(unsigned char *p)
{
    /* predict from p to line-end, without ANSI seq.
     */
    int off = 0;
    int inAnsi = 0;

    while (p < mf.end && *p != '\n')
    {
    if(inAnsi)
    {
        if(!ANSI_IN_ESCAPE(*p))
        inAnsi = 0;
    } else {
        if(*p == ESC_CHR)
        inAnsi = 1;
        else
        off ++;
    }
    p++;
    }
    return off;
}

MFPROTO int
MFDISP_DBCS_HEADERWIDTH(int originalw)
{
    return originalw - (originalw %2);
//    return (originalw >> 1) << 1;
}

#define MFDISP_FORCEUPDATE2TOP() { startline = 0; }
#define MFDISP_FORCEUPDATE2BOT() { endline   = MFDISP_PAGE - 1; }
#define MFDISP_FORCEDIRTY2BOT() \
    if(optimized == MFDISP_OPT_OPTIMIZED) { \
    optimized = MFDISP_OPT_FORCEDIRTY; \
    MFDISP_FORCEUPDATE2BOT(); \
    }

static char *override_msg = NULL;
static char *override_attr = NULL;

/*
 * display mf content from disps for MFDISP_PAGE
 */

void 
mf_display()
{
    int lines = 0, col = 0, currline = 0, wrapping = 0;
    int startline, endline;

    int optimized = MFDISP_OPT_CLEAR;

    /* why t_columns-1 here?
     * because BBS systems usually have a poor terminal system
     * and many stupid clients behave differently.
     * So we try to avoid using the last column, leave it for
     * BBS to place '\n' and CLRTOEOL.
     */
    const int headerw = MFDISP_DBCS_HEADERWIDTH(t_columns-1);
    const int dispw = headerw - (t_columns - headerw < 2);
    const int maxcol = dispw - 1;
    int newline_default = MFDISP_NEWLINE_CLEAR;

    if(mf.wraplines || mf.trunclines)
    MFDISP_DIRTY(); // we can't scroll with wrapped lines.

    mf.wraplines = 0;
    mf.trunclines = 0;
    mf.dispedlines = 0;

    MFDISP_FORCEUPDATE2TOP();
    MFDISP_FORCEUPDATE2BOT();

#ifdef PMORE_USE_OPT_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.
         */
        pmore_clrtoeol(b_lines, 0);
        // 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)
    {
        endline = scrll-1;      // v
        // clear the line which will be scrolled
        // to bottom (status line position).
        pmore_clrtoeol(b_lines, 0);
        // move(b_lines, 0);
        // clrtoeol();
    }
    else
    {
        startline = MFDISP_PAGE - scrll; // ^
    }
    move(startline, 0);
    optimized = MFDISP_OPT_OPTIMIZED;
    // 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 newline = newline_default;
    int predicted_linewidth = -1;
    int xprefix = mf.xpos;

#ifdef PMORE_USE_DBCS_WRAP
    unsigned char *dbcs_incomplete = NULL;
#endif

    currline = mf.lineno + lines;
    col = 0;

    if(!wrapping && mf.dispe < mf.end)
        mf.dispedlines++;

    if(optimized == MFDISP_OPT_FORCEDIRTY)
    {
        /* btw, apparently this line should be visible. 
         * if not, maybe something wrong.
         */
        pmore_clrtoeol(lines, 0);
    }

#ifdef PMORE_USE_ASCII_MOVIE
    if(mfmovie.mode == MFDISP_MOVIE_PLAYING_OLD &&
        mfmovie.compat24)
    {
        if(mf.dispedlines == 23)
        return;
    } 
    else if (mfmovie.mode == MFDISP_MOVIE_DETECTED)
    {
        // detected only applies for first page.
        // since this is not very often, let's prevent
        // showing control codes.
        if(mf_movieFrameHeader(mf.dispe, mf.end))
        MFDISP_SKIPCURLINE();
    }
    else if(mfmovie.mode == MFDISP_MOVIE_UNKNOWN || 
        mfmovie.mode == MFDISP_MOVIE_PLAYING)
    {
        if(mf_movieFrameHeader(mf.dispe, mf.end))
        switch(mfmovie.mode)
        {

            case MFDISP_MOVIE_UNKNOWN:
            mfmovie.mode = MFDISP_MOVIE_DETECTED;
            /* let's remove the first control sequence. */
            MFDISP_SKIPCURLINE();
            break;

            case MFDISP_MOVIE_PLAYING:
            /*
             * maybe we should do clrtobot() here,
             * but it's even better if we do clear()
             * all time. so we set dirty here for
             * next frame, and please set dirty before
             * playing.
             */
            MFDISP_DIRTY();
            return;
        }
    } 
#endif

    /* Is currentline visible? */
    if (lines < startline || lines > endline)
    {
        MFDISP_SKIPCURLINE();
        newline = MFDISP_NEWLINE_SKIP;
    }
    /* Now, consider what kind of line
     * (header, seperator, or normal text)
     * is current line.
     */
    else if (currline == fh.lines && bpref.rawmode == MFDISP_RAW_NA)
    {
        /* case 1, header seperator line */
        if (bpref.seperator & MFDISP_SEP_LINE)
        {
        outs(ANSI_COLOR(36));
        for(col = 0; col < headerw; col+=2)
        {
            // prints("%02d", col);
            outs("─");
        }
        outs(ANSI_RESET);
        }

        /* Traditional 'more' adds seperator as a newline.
         * This is buggy, however we can support this
         * by using wrapping features.
         * Anyway I(piaip) don't like this. And using wrap
         * leads to slow display (we cannt speed it up with
         * optimized scrolling.
         */
        if(bpref.seperator & MFDISP_SEP_WRAP) 
        {
        /* we have to do all wrapping stuff
         * in normal text section.
         * make sure this is updated.
         */
        wrapping = 1;
        mf.wraplines ++;
        MFDISP_FORCEDIRTY2BOT();
        if(mf.dispe > mf.start && 
            mf.dispe < mf.end &&
            *mf.dispe == '\n')
            mf.dispe --;
        }
        else
        MFDISP_SKIPCURLINE();
    } 
    else if (currline < fh.lines && bpref.rawmode == MFDISP_RAW_NA )
    {
        /* case 2, we're printing headers */
        const char *val = (const char*)fh.headers[currline];
        const char *name = _fh_disp_heads[currline];
        int w = headerw - FH_HEADER_LEN - 3;

        outs(ANSI_COLOR(47;34) " ");
        outs(name);
        outs(" " ANSI_COLOR(44;37) " "); 

        /* right floating stuff? */
        if (currline == 0 && fh.floats[0])
        {
        w -= ustrlen(fh.floats[0]) + ustrlen(fh.floats[1]) + 4;
        }

        prints("%-*.*s", w, w, 
            (val ? val : ""));

        if (currline == 0 && fh.floats[0])
        {
        outs(ANSI_COLOR(47;34) " ");
        outs((const char*)fh.floats[0]);
        outs(" " ANSI_COLOR(44;37) " "); 
        outs((const char*)fh.floats[1]);
        outs(" ");
        }

        outs(ANSI_RESET);
        MFDISP_SKIPCURLINE();
    } 
    else if(mf.dispe < mf.end)
    {
        /* case 3, normal text */
        long dist = mf.end - mf.dispe;
        long flResetColor = 0;
        int  srlen = -1;
        int breaknow = 0;

        unsigned char c;

        if(xprefix > 0 && !bpref.oldwrapmode && bpref.indicator)
        {
        outs(MFDISP_WNAV_INDICATOR);
        col++;
        }

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

        while(!breaknow && mf.dispe < mf.end && (c = *mf.dispe) != '\n')
        {
        if(inAnsi)
        {
            if (!ANSI_IN_ESCAPE(c))
            inAnsi = 0;
            /* whatever this is, output! */
            mf.dispe ++;
            switch(bpref.rawmode)
            {
            case MFDISP_RAW_NOANSI:
                /* TODO
                 * col++ here may be buggy. */
                if(col < t_columns)
                {
                /* we tried our best to determine */
                if(xprefix > 0)
                    xprefix --;
                else
                {
                    outc(c); 
                    col++;
                }
                }
                if(!inAnsi)
                outs(ANSI_RESET);
                break;
            case MFDISP_RAW_PLAIN:
                break;

            default:
                if(ANSI_IN_MOVECMD(c))
#ifdef PMORE_RESTRICT_ANSI_MOVEMENT
                c = 's'; // "save cursor pos"
#else
                    // some user cannot live without this.
                // make them happy.
                newline_default = newline = MFDISP_NEWLINE_MOVE;
#endif
                outc(c);
                break;
            }
            continue;

        } else {

            if(c == ESC_CHR)
            {
            inAnsi = 1;
            /* we can't output now because maybe
             * ptt_prints wants to do something.
             */
            }
            else if(sr.search_str && srlen < 0 &&  // support search
#ifdef PMORE_USE_DBCS_WRAP
                dbcs_incomplete == NULL &&
#endif
                mf.end - mf.dispe > sr.len &&
                sr.cmpfunc((char*)mf.dispe, (char*)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, (char*)mf.dispe, 3);  // ^[[*s
            mf.dispe += 2;

            if(bpref.rawmode)
                buf[0] = '*';
            else
            {
                if(strchr("sbmlpn", buf[2]) != NULL)
                {
                override_attr = ANSI_COLOR(1;37;41);
                override_msg = " 注意: 此頁有控制碼,"
                    "原內容並不一定有您真實個人資訊";
                }
                Ptt_prints(buf, sizeof(buf), NO_RELOAD); // result in buf
            }
            i = strlen(buf);

            if (col + i > maxcol)
                i = maxcol - col;
            if(i > 0)
            {
                buf[i] = 0;
                col += i;
                outs(buf);
            }
            inAnsi = 0;
            } else
#endif
            if(inAnsi)
            {
            switch(bpref.rawmode)
            {
                case MFDISP_RAW_NOANSI:
                /* TODO
                 * col++ here may be buggy. */
                if(col < t_columns)
                {
                    /* we tried our best to determine */
                    if(xprefix > 0)
                    xprefix --;
                    else
                    {
                    outs(ANSI_COLOR(1) "*");
                    col++;
                    }
                }
                break;
                case MFDISP_RAW_PLAIN:
                break;
                default:
                outc(ESC_CHR);
                break;
            }
            } else {
            int canOutput = 0;
            /* if col > maxcol,
             * because we have the space for
             * "indicators" (one byte),
             * so we can tolerate one more byte.
             */
            if(col <= maxcol)   // normal case
                canOutput = 1;
            else if (bpref.oldwrapmode && // oldwrapmode
                col < t_columns)
            {
                canOutput = 1;
                newline = MFDISP_NEWLINE_MOVE;
            } else {
                int off = 0;
                // put more efforts to determine
                // if we can use indicator space
                // determine real offset between \n
                if(predicted_linewidth < 0)
                predicted_linewidth = col + 1 +
                    MFDISP_PREDICT_LINEWIDTH(mf.dispe+1);
                off = predicted_linewidth - (col + 1);

                if (col + off <= (maxcol+1))
                {
                canOutput = 1;  // indicator space
                }
#ifdef PMORE_TRADITIONAL_FULLCOL
                else if (col + off < t_columns)
                {
                canOutput = 1;
                newline = MFDISP_NEWLINE_MOVE;
                }
#endif
            }

            if(canOutput)
            {
                /* the real place to output text
                 */
#ifdef PMORE_USE_DBCS_WRAP
                if(mf.xpos > 0 && dbcs_incomplete && col < 2)
                {
                /* col = 0 or 1 only */
                if(col == 0) /* no indicators */
                    c = ' ';
                else if(!bpref.oldwrapmode && bpref.indicator)
                    c = ' ';
                }

                if (dbcs_incomplete)
                dbcs_incomplete = NULL;
                else if(PMORE_DBCS_LEADING(c)) 
                dbcs_incomplete = mf.dispe;
#endif
                if(xprefix > 0)
                xprefix --;
                else
                {
                outc(c);
                col++;
                }

                if (srlen == 0)
                outs(ANSI_RESET);
                if(srlen >= 0)
                srlen --;
            }
            else
            /* wrap modes */
            if(mf.xpos > 0 || bpref.wrapmode == MFDISP_WRAP_TRUNCATE)
            {
                breaknow = 1;
                mf.trunclines ++;
                MFDISP_SKIPCURLINE();
                wrapping = 0;
            }
            else if (bpref.wrapmode == MFDISP_WRAP_WRAP)
            {
                breaknow = 1;
                wrapping = 1;
                mf.wraplines ++;
#ifdef PMORE_USE_DBCS_WRAP
                if(dbcs_incomplete)
                {
                mf.dispe = dbcs_incomplete;
                dbcs_incomplete = NULL;
                /* to be more dbcs safe,
                 * use the followings to
                 * erase printed character.
                 */
                if(col > 0) {
                    /* TODO BUG BUGGY
                     * using move is maybe actually non-sense
                     * because BBS terminal system cannot
                     * display this when ANSI escapes were used
                     * in same line.  However, on most
                     * situation this works.
                     * So we used an alternative, forced ANSI 
                     * move command.
                     */
                    // move(lines, col-1);
                    char ansicmd[16];
                    sprintf(ansicmd, ANSI_MOVETO(%d,%d),
                        lines+1, col-1+1);
                    /* to preven ANSI ESCAPE being tranlated as
                     * DBCS trailing byte. */
                    outc(' '); 
                    /* move back one column */
                    outs(ansicmd);
                    /* erase it (previous leading byte)*/
                    outc(' ');
                    /* go to correct position */
                    outs(ansicmd);
                }
                }
#endif
            }
            }
        }
        if(!breaknow)
            mf.dispe ++;
        }
        if(flResetColor)
        outs(ANSI_RESET);

        /* "wrapping" should be only in normal text section.
         * We don't support wrap within scrolling,
         * so if we have to wrap, invalidate all lines.
         */
        if(breaknow)
        {
        if(wrapping)
            MFDISP_FORCEDIRTY2BOT();

        if(!bpref.oldwrapmode && bpref.indicator && col < t_columns)
        {
            if(wrapping)
            outs(MFDISP_WRAP_INDICATOR);
            else
            outs(MFDISP_TRUNC_INDICATOR);
        } else {
            outs(ANSI_RESET);
        }
        }
        else
        wrapping = 0;
    }

    if(mf.dispe < mf.end && *mf.dispe == '\n') 
        mf.dispe ++;
    // else, we're in wrap mode.

    switch(newline)
    {
        case MFDISP_NEWLINE_SKIP:
        break;
        case MFDISP_NEWLINE_CLEAR:
        FORCE_CLRTOEOL();
        outc('\n');
        break;
        case MFDISP_NEWLINE_MOVE:
        move(lines+1, 0);
        break;
    }
    lines ++;
    }
    /*
     * we've displayed the file.
     * but if we got wrapped lines in last page,
     * mf.maxdisps may be required to be larger.
     */
    if(mf.disps == mf.maxdisps && mf.dispe < mf.end)
    {
    /*
     * never mind if that's caused by seperator
     * however this code is rarely used now.
     * only if no preload file.
     */
    if (bpref.seperator & MFDISP_SEP_WRAP &&
        mf.wraplines == 1 &&
        mf.lineno < fh.lines)
    {
        /*
         * o.k, now we know maxline should be one line forward.
         */
        mf_determinemaxdisps(+1, 1);
    } else 
    {
        /* not caused by seperator?
         * ok, then it's by wrapped lines.
         *
         * old flavor: go bottom: 
         *    mf_determinemaxdisps(0)
         * however we have "update" method now,
         * so we can achieve more user friendly behavior.
         */
        mf_determinemaxdisps(+mf.wraplines, 1);
    }
    }
    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",
    "(k/↑) (j/↓/Enter)   上捲/下捲一行",
    "(^B)(PgUp)(BackSpace) 上捲一頁",
    "(^F)(PgDn)(Space)(→) 下捲一頁",
    "(,/</S-TAB)(./>/TAB)  左/右捲動",
    "(0/g/Home) ($/G/End)  檔案開頭/結尾",
    "(;/:)                 跳至某行/某頁",
    "數字鍵 1-9            跳至輸入的頁數或行號",
    "\01其他功\能鍵",
    "(/" ANSI_COLOR(1;30) "/" ANSI_RESET 
       "s)                 搜尋字串",
    "(n/N)                 重複正/反向搜尋",
    "(Ctrl-T)              存入暫存檔",
    "(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!
    "(w/W/l)               切換自動斷行/斷行符號/分隔線顯示方式",
    "(p/z/o)               播放動畫/棋局打譜/切換傳統模式(狀態列與斷行方式)",
    "(q/←) (h/H/?/F1)     結束/本說明畫面",
#ifdef DEBUG
    "(d)                   切換除錯(debug)模式",
#endif
    /* You don't have to delete this copyright line.
     * It will be located in bottom of screen and overrided by
     * status line. Only user with big terminals will see this :)
     */
    "\01本系統使用 piaip 的新式瀏覽程式: pmore, piaip's more",
    NULL
};
/*
 * pmore utility macros
 */
MFPROTO void
PMORE_UINAV_FORWARDPAGE()
{
    /* Usually, a forward is just mf_forward(MFNAV_PAGE);
     * but because of wrapped lines...
     * This function is used when user tries to nagivate
     * with page request.
     * If you want to a real page forward, don't use this.
     * That's why we have this special function.
     */
    int i = mf.dispedlines - 1;

    if(mf_viewedAll())
    return;

    if(i < 1)
    i = 1;
    mf_forward(i);
}

MFPROTO void
PMORE_UINAV_FORWARDLINE()
{
    if(mf_viewedAll())
    return;
    mf_forward(1);
}

#define REENTRANT_RESTORE() { mf = bkmf; fh = bkfh; }

/*
 * piaip's more, a replacement for old more
 */
int 
pmore(char *fpath, int promptend)
{
    int flExit = 0, retval = 0;
    int ch = 0;
    int invalidate = 1;

    /* simple re-entrant hack
     * I don't want to write pointers everywhere,
     * and pmore should be simple enough (inside itself)
     * so we can do so.
     */

    MmappedFile bkmf;
    MF_PrettyFormattedHeader bkfh;

#ifdef PMORE_USE_ASCII_MOVIE
    RESET_MOVIE();
#endif

    bkmf = mf; /* simple re-entrant hack */
    bkfh = fh;
    RESETMF();
    RESETFH();
    
    override_msg = NULL; /* elimiate pending errors */

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

    clear();
    while(!flExit)
    {
    if(invalidate)
    {
        mf_display(); 
        invalidate = 0;
    }

    /* in current implementation,
     * we want to invalidate for each keypress.
     */
    invalidate = 1;

#ifdef  PMORE_TRADITIONAL_PROMPTEND

    if(promptend == NA)
    {
#ifdef PMORE_USE_ASCII_MOVIE
        if(mfmovie.mode == MFDISP_MOVIE_DETECTED)
        {
        /* quick auto play */
        mfmovie.mode = MFDISP_MOVIE_YES;
        RESET_MOVIE();
        mfmovie.mode = MFDISP_MOVIE_PLAYING;
        mf_determinemaxdisps(0, 0); // display until last line
        mf_movieNextFrame();
        MFDISP_DIRTY();
        continue;
        } else if (mfmovie.mode != MFDISP_MOVIE_PLAYING)
#endif
        break;
    }
#else
    if(promptend == NA && mf_viewedAll())
        break;
#endif
    move(b_lines, 0);
    // clrtoeol(); // this shall be done in mf_display to speed up.

#ifdef PMORE_USE_ASCII_MOVIE
    switch (mfmovie.mode)
    {
        case MFDISP_MOVIE_UNKNOWN:
        mfmovie.mode = MFDISP_MOVIE_NO;
        break;

        case MFDISP_MOVIE_DETECTED:
        mfmovie.mode = MFDISP_MOVIE_YES;
        {
            // query if user wants to play movie.

            int w = t_columns-1;
            const char *s = 
            " 這份文件是可播放的文字動畫，要開始播放嗎？ [Y/n]";

            outs(ANSI_RESET ANSI_COLOR(1;33;44));
            w -= strlen(s); outs(s);

            while(w-- > 0) outc(' '); outs(ANSI_RESET);
            w = tolower(igetch());

            if(     w != 'n' && 
                w != KEY_UP && w != KEY_LEFT &&
                w != 'q')
            {
            RESET_MOVIE();
            mfmovie.mode = MFDISP_MOVIE_PLAYING;
            mf_determinemaxdisps(0, 0); // display until last line
            mf_movieNextFrame();
            MFDISP_DIRTY();
            continue;
            }
            /* else, we have to clean up. */
            move(b_lines, 0);
            clrtoeol();
        }
        break;

        case MFDISP_MOVIE_PLAYING_OLD:
        case MFDISP_MOVIE_PLAYING:

        mf_moviePromptPlaying();

        if(mf_movieSyncFrame())
        {
            /* user did not hit anything.
             * play next frame.
             */
            if(mfmovie.mode == MFDISP_MOVIE_PLAYING)
            {
            if(!mf_movieNextFrame())
            {
                STOP_MOVIE();
                mf_determinemaxdisps(MFNAV_PAGE, 0);
                mf_forward(0);

                if(promptend == NA)
                {
                /* if we played to end,
                 * no need to prevent pressanykey().
                 */
                flExit = 1, retval = 0;
                }
            }
            }
            else if(mfmovie.mode == MFDISP_MOVIE_PLAYING_OLD)
            {
            if(mf_viewedAll())
            {
                mfmovie.mode = MFDISP_MOVIE_NO;
                mf_determinemaxdisps(MFNAV_PAGE, 0);
                mf_forward(0);
            }
            else
            {
                if(!mfmovie.compat24)
                PMORE_UINAV_FORWARDPAGE();
                else
                mf_forward(22);
            }
            }
        } else {
            /* TODO simple navigation here? */

            /* stop playing */
            if(mfmovie.mode == MFDISP_MOVIE_PLAYING)
            {
            STOP_MOVIE();
            if(promptend == NA)
            {
                flExit = 1, retval = READ_NEXT;
            }
            }
            else if(mfmovie.mode == MFDISP_MOVIE_PLAYING_OLD)
            mfmovie.mode = MFDISP_MOVIE_NO;

            mf_determinemaxdisps(MFNAV_PAGE, 0);
            mf_forward(0);
        }
        continue;
    }
#endif

    /* PRINT BOTTOM STATUS BAR */
#ifdef DEBUG
    if(debug)
    {
        /* in debug mode don't print ANSI codes
         * because themselves are buggy.
         */
        prints("L#%ld(w%ld,lp%ld) pmt=%d Dsp:%08X/%08X/%08X, "
            "F:%08X/%08X(%d) tScr(%dx%d)",
            mf.lineno, mf.wraplines, mf.lastpagelines,
            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
#endif
    {
        char *printcolor;

        char buf[256];  // orz
        int prefixlen = 0;
        int barlen = 0;
        int postfix1len = 0, postfix2len = 0;

        int progress  = 
        (int)((unsigned long)(mf.dispe-mf.start) * 100 / mf.len);
        /*
         * page determination is hard.
         * should we use starting line, or finishing line?
         */
        int nowpage = 
        (int)((mf.lineno + mf.dispedlines/2) / MFNAV_PAGE)+1;
        int allpages = -1; /* unknown yet */
        if (mf.maxlinenoS >= 0)
        {
        allpages = 
        (int)((mf.maxlinenoS + mf.lastpagelines -
               ((bpref.seperator & MFDISP_SEP_WRAP) &&
            (fh.lines >= 0) ? 0:1)) / MFNAV_PAGE)+1;
        if (mf.lineno >= mf.maxlinenoS || nowpage > allpages)
            nowpage = allpages;
        /*
            nowpage = 
            (int)((mf.lineno + mf.dispedlines-2) / MFNAV_PAGE)+1 ;
            */
        }
        /* why -2 and -1?
         * because we want to determine by nav_page,
         * and mf.dispedlines is based on disp_page (nav_page+1)
         * mf.lastpagelines is based on nav_page
         */

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

        outs(ANSI_RESET);
        outs(printcolor);

        if(bpref.oldstatusbar)
        {

        prints("  瀏覽 P.%d(%d%%)  %s  %-30.30s%s",
            nowpage,
            progress,
            ANSI_COLOR(31;47), 
            "(h)" 
            ANSI_COLOR(30) "求助  "
            ANSI_COLOR(31) "→↓[PgUp][",
            "PgDn][Home][End]"
            ANSI_COLOR(30) "游標移動  "
            ANSI_COLOR(31) "←[q]"
            ANSI_COLOR(30) "結束   ");

        } else {

        if(allpages >= 0)
            sprintf(buf,
                "  瀏覽 第 %1d/%1d 頁 (%3d%%) ",
                nowpage,
                allpages,
                progress
               );
        else
            sprintf(buf,
                "  瀏覽 第 %1d 頁 (%3d%%) ",
                nowpage,
                progress
               );
        outs(buf); prefixlen += strlen(buf);

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

        if(override_msg)
        {
            buf[0] = 0;
            if(override_attr) outs(override_attr);
            snprintf(buf, sizeof(buf), override_msg);
            override_msg = NULL;
        }
        else
        if(mf.xpos > 0)
        {
            snprintf(buf, sizeof(buf),
                " 顯示範圍: %d~%d 欄位, %02d~%02d 行",
                (int)mf.xpos+1, 
                (int)(mf.xpos + t_columns-(mf.trunclines ? 2 : 1)),
                (int)(mf.lineno + 1),
                (int)(mf.lineno + mf.dispedlines)
               );
        } else {
            snprintf(buf, sizeof(buf),
                " 目前顯示: 第 %02d~%02d 行",
                (int)(mf.lineno + 1),
                (int)(mf.lineno + mf.dispedlines)
               );
        }

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

        postfix1len = 12;   // check msg below
        postfix2len = 10;
        if(mf_viewedAll()) postfix1len = 15;

        if (prefixlen + postfix1len + postfix2len + 1 > t_columns)
        {
            postfix1len = 0;
            if (prefixlen + postfix1len + postfix2len + 1 > t_columns)
            postfix2len = 0;
        }
        barlen = t_columns - 1 - postfix1len - postfix2len - prefixlen;

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

        if(postfix1len > 0)
            outs(
            mf_viewedAll() ?
                ANSI_COLOR(0;31;47)"(y)" ANSI_COLOR(30) "回信"
                ANSI_COLOR(31) "(X)" ANSI_COLOR(30) "推文 "
            :
                ANSI_COLOR(0;31;47) "(h)" 
                ANSI_COLOR(30) "按鍵說明 "
            );
        if(postfix2len > 0)
            outs(
                ANSI_COLOR(0;31;47) "←[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:
        /* because we have other keys to do so,
         * disable now.
         */
        /*
        if(mf.xpos > 0)
        {
            mf.xpos --;
            break;
        }
        */
        flExit = 1, retval = FULLUPDATE;
        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 'k': case 'K':
        mf_backward(1);
        break;
        case 'j': case 'J':
        PMORE_UINAV_FORWARDLINE();
        break;

        case Ctrl('F'):
        case KEY_PGDN:
        PMORE_UINAV_FORWARDPAGE();
        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();

#ifdef PMORE_ACCURATE_WRAPEND
        /* allright. in design of pmore,
         * it's possible that when user navigates to file end,
         * a wrapped line made nav not 100%.
         */
        mf_display();
        invalidate = 0;

        if(!mf_viewedAll())
        {
            /* one more try. */
            mf_goBottom();
            invalidate = 1;
        }
#endif
        break;

        /* Compound Navigation */
        case '.':
        if(mf.xpos == 0)
            mf.xpos ++;
        mf.xpos ++;
        break;
        case ',':
        if(mf.xpos > 0)
            mf.xpos --;
        break;
        case '\t':
        case '>':
        //if(mf.xpos == 0 || mf.trunclines)
            mf.xpos = (mf.xpos/8+1)*8;
        break;
        /* acronym form shift-tab, ^[[Z */
        /* however some terminals does not send that. */
        case KEY_STAB:
        case '<':
        mf.xpos = (mf.xpos/8-1)*8;
        if(mf.xpos < 0) mf.xpos = 0;
        break;
        case '\r':
        case '\n':
        case KEY_DOWN:
        if (mf_viewedAll() ||
            (promptend == 2 && (ch == '\r' || ch == '\n')))
            flExit = 1, retval = READ_NEXT;
        else
            PMORE_UINAV_FORWARDLINE();
        break;

        case ' ':
        if (mf_viewedAll())
            flExit = 1, retval = READ_NEXT;
        else
            PMORE_UINAV_FORWARDPAGE();
        break;
        case KEY_RIGHT:
        if(mf_viewedAll())
            promptend = 0, flExit = 1, retval = 0;
        else
        {
            /* if mf.xpos > 0, widenav mode. */
            /* because we have other keys to do so,
             * disable it now.
             */
            /*
            if(mf.trunclines > 0)
            {
            if(mf.xpos == 0)
                mf.xpos++;
            mf.xpos++;
            }
            else if (mf.xpos == 0)
            */
            PMORE_UINAV_FORWARDPAGE();
        }
        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
            PMORE_UINAV_FORWARDPAGE();
        break;
        /* ------------------ SEARCH  KEYS ------------------ */
        case 's':
        case '/':
        {
            char sbuf[81] = "";
            char ans[4] = "n";

            if(sr.search_str) {
            free(sr.search_str);
            sr.search_str = NULL;
            }

            getdata(b_lines - 1, 0, "[搜尋]關鍵字:", sbuf,
                40, DOECHO);

            if (sbuf[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 if (*ans == 'q')
                sbuf[0] = 0;
            else
                sr.cmpfunc = strncasecmp;
            }
            sr.len = strlen(sbuf);
            if(sr.len) sr.search_str = (unsigned char*)strdup(sbuf);
            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[16] = "";
            int  i = 0;
            int  pageMode = (ch != ':');
            if (ch >= '1' && ch <= '9')
            buf[0] = ch, buf[1] = 0;

            pmore_clrtoeol(b_lines-1, 0);
            getdata_buf(b_lines-1, 0, 
                (pageMode ? 
                 "跳至此頁(若要改指定行數請在結尾加.): " : 
                 "跳至此行: "),
                buf, 8, DOECHO);
            if(buf[0]) {
            i = atoi(buf);
            if(buf[strlen(buf)-1] == '.')
                pageMode = 0;
            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 KEY_F1:
        case '?':
        // help
        show_help(pmore_help);
        MFDISP_DIRTY();
        break;

        case 'E':
        // admin edit any files other than ve help file
        // and posts in Security board
        if (    HasUserPerm(PERM_SYSOP) && 
            (strcmp(fpath, "etc/ve.hlp") != 0) &&
            (strcmp(currboard, "Security") != 0)
            )
        {
#ifdef PMORE_LOG_SYSOP_EDIT
            time4_t t = time4(NULL);

            log_file("log/security", LOG_VF|LOG_CREAT,
                "%d %24.24s %d %s admin edit file=%s\n", 
                t, ctime4(&t), getpid(), cuser.userid, fpath);
#endif // PMORE_LOG_SYSOP_EDIT

            mf_detach();
            vedit(fpath, NA, NULL);

            REENTRANT_RESTORE();
            return 0;
        }
        break;
        case 'w':
        switch(bpref.wrapmode)
        {
            case MFDISP_WRAP_WRAP:
            bpref.wrapmode = MFDISP_WRAP_TRUNCATE;
            // override_attr = ANSI_COLOR(31);
            // override_msg = " 已設定為截行模式(不自動斷行)";
            vmsg("斷行方式已設定為截行模式(不自動斷行)");
            break;

            case MFDISP_WRAP_TRUNCATE:
            bpref.wrapmode = MFDISP_WRAP_WRAP;
            // override_attr = ANSI_COLOR(34);
            // override_msg = " 已設定為自動斷行模式";
            vmsg("斷行方式已設定為自動斷行(預設)");
            break;
        }
        MFDISP_DIRTY();
        break;
        case 'W':
        bpref.indicator = !bpref.indicator;
        if(bpref.indicator)
            // override_attr = ANSI_COLOR(34);
            // override_msg = " 顯示斷行符號";
            vmsg("設定為斷行時顯示斷行符號(預設)");
        else
            // override_attr = ANSI_COLOR(31);
            // override_msg = " 不再顯示斷行符號";
            vmsg("設定為斷行時不顯示斷行符號");
        MFDISP_DIRTY();
        break;
        case 'o':
        bpref.oldwrapmode  = !bpref.oldwrapmode;
        bpref.oldstatusbar = !bpref.oldstatusbar;
        MFDISP_DIRTY();
        break;
        case 'l':
        switch(bpref.seperator)
        {
            case MFDISP_SEP_OLD:
            bpref.seperator = MFDISP_SEP_LINE;
            // override_attr = ANSI_COLOR(31);
            // override_msg = " 設定為單行分隔線";
            vmsg("分隔線設定為單行分隔線");
            break;
            case MFDISP_SEP_LINE:
            bpref.seperator = 0;
            // override_attr = ANSI_COLOR(31);
            // override_msg = " 設定為無分隔線";
            vmsg("設定為無分隔線");
            break;
            default:
            bpref.seperator = MFDISP_SEP_OLD;
            // override_attr =  ANSI_COLOR(34);
            // override_msg =  " 傳統分隔線加空行";
            vmsg("分隔線設定為傳統分隔線加空行(預設)");
            break;
        }
        MFDISP_DIRTY();
        break;
        case '\\':
        case '|':
        if(ch == '|')
            bpref.rawmode += MFDISP_RAW_MODES-1;
        else
        {
            /* '\\' */

            /* should we do first time prompt checking here,
             * or remove hotkey '\\'?
             */
            static unsigned char first_prompt = 1;
            if(first_prompt)
            {
            char ans[3] = "";
            getdata(b_lines - 1, 0, 
                "確定改變預設內容顯示方式嗎？ "
                "(若不懂請直接按 Enter)[y/N]"
                ,
                ans, 3, LCECHO);
            if(ans[0] != 'y')
                break;
            first_prompt = 0;
            }
            bpref.rawmode ++;
        }
        bpref.rawmode %= MFDISP_RAW_MODES;
        switch(bpref.rawmode)
        {
            case MFDISP_RAW_NA:
            // override_attr = ANSI_COLOR(34);
            // override_msg = " 顯示預設格式化內容";
            vmsg("顯示方式設定為預設格式化內容");
            break;
            /*
            case MFDISP_RAW_NOFMT:
            // override_attr = ANSI_COLOR(31);
            // override_msg = " 省略自動格式化";
            break;
            */
            case MFDISP_RAW_NOANSI:
            // override_attr = ANSI_COLOR(33);
            // override_msg = " 顯示原始 ANSI 控制碼";
            vmsg("顯示方式設定為顯示原始 ANSI 控制碼");
            break;
            case MFDISP_RAW_PLAIN:
            // override_attr = ANSI_COLOR(37);
            // override_msg = " 顯示純文字";
            vmsg("顯示方式設定為純文字");
            break;
        }
        MFDISP_DIRTY();
        break;
#ifdef PMORE_USE_ASCII_MOVIE
        case 'p':
        /* play ascii movie again
         */
        if(mfmovie.mode == MFDISP_MOVIE_YES)
        {
            RESET_MOVIE();
            mfmovie.mode = MFDISP_MOVIE_PLAYING;
            mf_determinemaxdisps(0, 0); // display until last line
            /* it is said that it's better not to go top. */
            // mf_goTop();
            mf_movieNextFrame();
            MFDISP_DIRTY();
        } 
        else if (mfmovie.mode == MFDISP_MOVIE_NO)
        {
            static char buf[10]="1";
            //move(b_lines-1, 0);
            
            /* 
             * TODO scan current page to confirm if this is a new style movie
             */
            pmore_clrtoeol(b_lines-1, 0);
            getdata_buf(b_lines - 1, 0, 
                "這可能是傳統動畫檔, "
                "若要直接播放請輸入速度(秒): "
                ,
                buf, 8, LCECHO);

            if(buf[0])
            {
            float nf = 0;
            nf = atof(buf); // sscanf(buf, "%f", &nf);
            RESET_MOVIE();

            mfmovie.mode = MFDISP_MOVIE_PLAYING_OLD;
            mf_float2tv(nf, &mfmovie.frameclk);
            mfmovie.compat24 = 0;
            /* are we really going to start? check termsize! */
            if (t_lines != 24)
            {
                char ans[4];
                pmore_clrtoeol(b_lines-1, 0);
                getdata(b_lines - 1, 0, 
                "傳統動畫是以 24 行為單位設計的, "
                "要模擬 24 行嗎? (否則會用現在的行數)[Yn] "
                , ans, 3, LCECHO);
                if(ans[0] == 'n')
                mfmovie.compat24 = 0;
                else
                mfmovie.compat24 = 1;
            }
            mf_determinemaxdisps(0, 0); // display until last line
            MFDISP_DIRTY();
            }
        }
        break;
#endif

#ifdef DEBUG
        case 'd':
        debug = !debug;
        MFDISP_DIRTY();
        break;
#endif

        case 'z':
        ChessReplayGame(fpath);
        break;
    }
    /* DO NOT DO ANYTHING HERE. NOT SAFE RIGHT NOW. */
    }

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

    REENTRANT_RESTORE();
    return retval;
}

// ---------------------------------------------------- Extra modules

#ifdef PMORE_USE_ASCII_MOVIE
void 
mf_float2tv(float f, struct timeval *ptv)
{
    if(f < MOVIE_MIN_FRAMECLK)
    f = MOVIE_MIN_FRAMECLK;
    if (f > MOVIE_MAX_FRAMECLK)
    f = MOVIE_MAX_FRAMECLK;

    ptv->tv_sec = (long) f;
    ptv->tv_usec = (f - (long)f) * MOVIE_SECOND_U;
}

int 
mf_str2float(unsigned char *p, unsigned char *end, float *pf)
{
    char buf[16] = {0};
    int cbuf = 0;

    /* process time */
    while ( p < end && 
        cbuf < sizeof(buf)-1 &&
        (isdigit(*p) || *p == '.' || *p == '+' || *p == '-'))
    buf[cbuf++] = *p++;

    if (!cbuf)
    return 0;

    buf[cbuf] = 0;
    *pf = atof(buf);

    return 1;
}

/*
 * maybe you can use add_io or you have other APIs in
 * your I/O system, but we'll do it here.
 * override if you have better methods.
 */
int 
pmore_wait_key(struct timeval *ptv, int dorefresh)
{
    int sel = 0;
    fd_set readfds;
    int c = 0;

    if (dorefresh)
    refresh();

    do {
    // if already something in queue,
    // detemine if ok to break.
    while ( num_in_buf() > 0)
    {
        if (!mf_movieMaskedInput((c = igetch())))
        return c;
    }

    // wait for real user interaction
    FD_ZERO(&readfds);
    FD_SET(0, &readfds);

#ifdef STATINC
    STATINC(STAT_SYSSELECT);
#endif
    sel = select(1, &readfds, NULL, NULL, ptv);

    // if select() stopped by other interrupt,
    // do it again.
    if (sel < 0 && errno == EINTR)
        continue;

    // if (sel > 0), try to read.
    // note: there may be more in queue.
    // will be processed at next loop.
    if (sel > 0 && !mf_movieMaskedInput((c = igetch())))
        return c;

    } while (sel > 0);

    // now, maybe something for read (sel > 0)
    // or time out (sel == 0)
    // or weird error (sel < 0)
    return (sel == 0) ? 0 : 1;
}

int
mf_moviePromptPlaying()
{
    int w = t_columns - 1;
    // s may change to anykey...
    const char *s = " >>> 動畫播放中... 可按 q 或 Ctrl-C 停止";

    move(b_lines, 0);
    if (mfmovie.interactive)
    {
    outs(ANSI_RESET ANSI_COLOR(1;34;47));
    s = " >>> 互動式動畫播放中... 可按 q 或 Ctrl-C 停止";
    } else {
    outs(ANSI_RESET ANSI_COLOR(1;30;47));
    }

    w -= strlen(s); outs(s); 

    while(w-- > 0) outc(' '); outs(ANSI_RESET);
    return 1;
}

int
mf_moviePromptOptions(
    int isel, int maxsel,
    int key, 
    char *text, unsigned int szText)
{
    if (isel == maxsel)
    outs(ANSI_COLOR(1;33;41));
    else
    outs(ANSI_COLOR(1;33;44));

    outs("[");

    if (isprint(key))
    {
    outc(key);
    outs(".");
    } else {
    // named keys
    if (key == KEY_UP)   outs("↑ ");
    if (key == KEY_LEFT) outs("← ");
    if (key == KEY_DOWN) outs("↓ ");
    if (key == KEY_RIGHT)outs("→ ");
    }

    if (!text) 
    { 
    // default option text
    text = "???"; 
    szText = strlen(text);
    }

    outs_n(text, szText);
    outs("]" ANSI_COLOR(30;47) " ");

    return 1;
}

int 
mf_movieNamedKey(int c)
{
    switch (c)
    {
    case 'u':
        return KEY_UP;
    case 'd':
        return KEY_DOWN;
    case 'l':
        return KEY_LEFT;
    case 'r':
        return KEY_RIGHT;
    default:
        break;
    }
    return 0;
}

int 
mf_movieMaskedInput(int c)
{
    unsigned char *p = mfmovie.optkeys;

    if (!p)
    return 0;

    // some keys cannot be masked
    if (c == 'q' || c == 'Q' || c == Ctrl('C'))
        return 0;

    // special: mask all
    if (mf.end - p >= 4 && memcmp(p, "@all", 4) == 0)
    return 1;

    // general look up
    while (p < mf.end && *p && *p != '\n' && *p != '#')
    {
    if (*p == '@' && mf.end - p > 1 
        && isalnum(*(p+1))) // named key
    {
        p++;
        if (mf_movieNamedKey(*p) == c)
        return 1;
    } else {
        if ((int)*p == c)
        return 1;
    }
    p++;
    }
    return 0;
}

unsigned char * 
mf_movieFrameHeader(unsigned char *p, unsigned char *end)
{
    // ANSI has ESC_STR [8m as "Conceal" but
    // not widely supported, even PieTTY.
    // So let's go back to fixed format...
    static char *patHeader = "==" ESC_STR "[30;40m^L";
    static char *patHeader2= ESC_STR "[30;40m^L"; // patHeader + 2; // "=="
    static size_t szPatHeader   = 12; // strlen(patHeader);
    static size_t szPatHeader2  = 10; // strlen(patHeader2);

    size_t sz = end - p;

    if (sz < 1) return NULL;
    if(*p == 12)    // ^L
    return p+1;

    if (sz < 2) return NULL;
    if( *p == '^' &&
        *(p+1) == 'L')
    return p+2;

    // Add more frame headers
    if (sz < szPatHeader2) return NULL;
    if (memcmp(p, patHeader2, szPatHeader2) == 0)
    return p + szPatHeader2;

    if (sz < szPatHeader) return NULL;
    if (memcmp(p, patHeader, szPatHeader) == 0)
    return p + szPatHeader;

    return NULL;
}

int 
mf_movieGotoNamedFrame(const unsigned char *name, const unsigned char *end)
{
    const unsigned char *p = name;
    size_t sz = 0;

    // resolve name first
    while (p < end && isalnum(*p))
    p++;
    sz = p - name;

    if (sz < 1) return 0;

    // now search entire file for frame

    mf_goTop();

    do
    {
    if ((p = mf_movieFrameHeader(mf.disps, mf.end)) == NULL ||
        *p != ':')
        continue; 

    // got some frame. let's check the name
    p++;
    if (mf.end - p < sz)
        continue;

    if (memcmp(p, name, sz) == 0)
        return 1;

    } while  (mf_forward(1) > 0);
    return 0;
}

int 
mf_movieGotoFrame(int fno)
{
    mf_goTop();

    while (fno > 0)
    {
    while ( mf_movieFrameHeader(mf.disps, mf.end) == NULL)
    {
        if (mf_forward(1) < 1)
        return 0;
    }

    fno --;

    if (fno > 0)
        mf_forward(1);
    }
    return 1;
}

int 
mf_movieCurrentFrameNo()
{
    int no = 0;
    unsigned char *p = mf.disps;
    mf_goTop();

    do
    {
    if ( mf_movieFrameHeader(mf.disps, mf.end))
        no++;

    if (mf.disps >= p)
        break;

    if (mf_forward(1) < 1)
        break;

    } while ( 1 ); // mf.disps < p);

    return no;
}

int
mf_parseOffsetCmd(
    unsigned char *s, unsigned char *end,
    int base)
{
    // return is always > 0, or base.
    int v = 0;

    if (s >= end)
    return base;

    v = atoi((char*)s);

    if (*s == '+' || *s == '-')
    {
    // relative format
    v = base + v;
    } else if (isdigit(*s)) {
    // absolute format
    } else {
    // error format?
    v = 0;
    }

    if (v <= 0)
    v = base;
    return v;
}

int
mf_movieExecuteOffsetCmd(unsigned char *s, unsigned char *end)
{
    // syntax: type[+-]offset
    //
    // type:   l(line), f(frame), p(page).
    // +-:     if empty, absolute. if assigned, relative.
    // offset: is 1 .. N for all cases

    int curr = 0, newno = 0;
    
    switch(*s)
    {
    case 'p':   
        // by page
        curr = (mf.lineno / MFDISP_PAGE) + 1;
        newno = mf_parseOffsetCmd(s+1, end, curr);
#ifdef DEBUG
        vmsgf("page: %d -> %d\n", curr, newno);
#endif // DEBUG
        // prevent endless loop
        if (newno == curr)
        return 0;

        return mf_goto((newno -1) * MFDISP_PAGE);

    case 'f':
        // by frame
        // TODO modify frame number so it follows 1..N
        curr = mf_movieCurrentFrameNo();
        newno = mf_parseOffsetCmd(s+1, end, curr);
#ifdef DEBUG
        vmsgf("frame: %d -> %d\n", curr, newno);
#endif // DEBUG
        // prevent endless loop
        if (newno == curr)
        return 0;

        return mf_movieGotoFrame(newno);

    case 'l':
        // by lines
        curr = mf.lineno + 1;
        newno = mf_parseOffsetCmd(s+1, end, curr);
#ifdef DEBUG
        vmsgf("line: %d -> %d\n", curr, newno);
#endif // DEBUG
        // prevent endless loop
        if (newno == curr)
        return 0;

        return mf_goto(newno-1);

    case ':':
        // by names
        return mf_movieGotoNamedFrame(s+1, end);

    default:
        // not supported yet
        break;
    }
    return 0;
}


int 
mf_movieOptionHandler(unsigned char *opt, unsigned char *end)
{
    // format: #time#key1,cmd,text1#key2,cmd,text2#
    // if key  is empty, use auto-increased key.
    // if cmd  is empty, invalid.
    // if text is empty, display key only or hide if time is assigned.
    
    int ient = 0;
    unsigned char *pkey = NULL, *cmd = NULL, *text = NULL;
    unsigned int szCmd = 0, szText = 0;
    unsigned char *p = opt;
    int key = 0;
    float optclk = -1.0f; // < 0 means infinite wait
    struct timeval tv;

    int isel = 0, c = 0, maxsel = 0, selected = 0;
    int newOpt = 1;
    int hideOpts = 0;

    // TODO handle line length
    // TODO restrict option size
    
    // set up timer (opt points to optional time now)
    do {
    p = opt;
    while (  p < end &&
        (isdigit(*p) || *p == '+' || *p == '-' || *p == '.') )
        p++;

    // if no number, abort.
    if (p == opt || (p < end && *p != '#')) break;

    // p looks like valid timer now
    if (mf_str2float(opt, p, &optclk))
    {
        // conversion failed.
        if (optclk == 0)
        optclk = -1.0f;
    }

    // point opt to new var after #.
    opt = p + 1;
    break;

    } while (1);
    
    // UI Selection
    do {
    // do c test here because we need parser to help us
    // finding the selection
    if (c == '\r' || c == '\n' || c == ' ')
    {
        selected = 1;
    }

    newOpt = 1;

    // parse (key,frame,text)
    for (   p = opt, ient = 0, maxsel = 0,
        key = '0';  // default command
        p < end && *p != '\n'; p++)
    {
        if (newOpt)
        {
        // prepare for next loop
        pkey = p;
        cmd = text = NULL;
        szCmd = szText = 0;
        ient = 0;
        newOpt = 0;
        }

        // calculation of fields
        if (*p == ',' || *p == '#')
        {
        switch (++ient)
        {
            // case 0 is already processed.
            case 1:
            cmd = p+1;
            break;

            case 2:
            text = p+1;
            szCmd = p - cmd;
            break;

            case 3:
            szText = p - text;

            default:
            // unknown parameters
            break;
        }
        } 

        // ready to parse one option
        if (*p == '#')
        {
        newOpt = 1;

        // first, fix pointers
        if (szCmd == 0 || *cmd == ',' || *cmd == '#')
        { cmd = NULL; szCmd = 0; }

        // quick abort if option is invalid.
        if (!cmd) 
            continue;

        if (szText == 0 || *text == ',' || *text == '#')
        { text = NULL; szText = 0; }

        // assign key
        if (*pkey == ',' || *pkey == '#')
            key++;
        else
        {
            // named key?
            int nk = 0;

            if (*pkey == '@' && 
                ++ pkey < end &&
                (nk = mf_movieNamedKey(*pkey)))
            {
            key = nk;
            } else 
            key = *pkey;
            // warning: pkey may be changed after this.
        }

        // calculation complete.
        
        // print option
        if (!hideOpts && maxsel == 0 && text == NULL)
        {
            hideOpts = 1;
            mf_moviePromptPlaying();
            // prevent more hideOpt test
        }

        if (!hideOpts)
        {
            // print header
            if (maxsel == 0)
            {
            pmore_clrtoeol(b_lines, 0);
            outs(ANSI_COLOR(31;47)" >> 請輸入選項: ");
            }

            mf_moviePromptOptions(
                isel, maxsel, key,
                (char*)text, szText);
        }

        // handle selection
        if (c == key)
        {
            // hotkey pressed
            selected = 1;
            isel = maxsel;
        }

        maxsel ++;

        // parse complete.
        // test if this item is selected.
        if (selected && isel == maxsel - 1)
            break;
        }
    }

    if (selected || maxsel == 0)
        break;

    // finish the selection bar
    if (!hideOpts && maxsel > 0)
        outs(" " ANSI_RESET);

    // wait for input
    if (optclk > 0)
    {
        // timed interaction

        // disable optkeys to allow masked input
        unsigned char *tmpopt = mfmovie.optkeys;
        mfmovie.optkeys = NULL;

        mf_float2tv(optclk, &tv);
        c = pmore_wait_key(&tv, 1);
        mfmovie.optkeys = tmpopt;

        // if timeout, drop.
        if (!c)
        return 0;
    } else {
        // infinite wait
        c = igetch();
    }

    // parse keyboard input
    if (c == 'q' || c == 'Q' || c == Ctrl('C'))
    {
        // cannot be masked,
        // also force stop of playback
        STOP_MOVIE();
        vmsg("已強制中斷互動式系統。");
        return 0;
    }

    // standard navigation keys.
    if (mf_movieMaskedInput(c))
        continue;

    // these keys can be masked
    if (c == KEY_LEFT || c == KEY_UP)
    {
        if (isel > 0) isel --;
    } 
    else if (c == KEY_RIGHT || c == KEY_TAB || c == KEY_DOWN)
    {
        if (isel < maxsel-1) isel ++;
    } 
    else if (c == KEY_HOME)
    {
        isel = 0;
    } 
    else if (c == KEY_END)
    {
        isel = maxsel -1;
    } 

    } while ( !selected );

    // selection is made now.
    pmore_clrtoeol(b_lines, 0);

#ifdef DEBUG
    prints("selection: %d\n", isel);
    igetch();
#endif

    // Execute Selection
    if (!cmd || !szCmd)
    return 0;

    return mf_movieExecuteOffsetCmd(cmd, cmd+szCmd);
}

/*
 * mf_movieSyncFrame: 
 *  wait until synchronization, and flush break key (if any).
 * return meaning:
 * I've got synchronized.
 * If no (user breaks), return 0
 */
int mf_movieSyncFrame()
{
    if (mfmovie.pause)
    {
    mfmovie.pause = 0;
    vmsg(" >>> 暫停播放動畫，請按任意鍵繼續。 <<<");
    return 1;
    } 
    else if (mfmovie.options)
    {
    unsigned char *opt = mfmovie.options;
    mfmovie.options = NULL;
    mf_movieOptionHandler(opt, mf.end);
    return 1;
    }
    else if (mfmovie.synctime.tv_sec > 0)
    {
    /* synchronize world timeline model */
    struct timeval dv;
    gettimeofday(&dv, NULL);
    dv.tv_sec = mfmovie.synctime.tv_sec - dv.tv_sec;
    if(dv.tv_sec < 0)
        return 1;
    dv.tv_usec = mfmovie.synctime.tv_usec - dv.tv_usec;
    if(dv.tv_usec < 0) {
        dv.tv_sec --;
        dv.tv_usec += MOVIE_SECOND_U;
    }
    if(dv.tv_sec < 0)
        return 1;

    return !pmore_wait_key(&dv, 1);
    } else {
    /* synchronize each frame clock model */
    /* because Linux will change the timeval passed to select,
     * let's use a temp value here.
     */
    struct timeval dv = mfmovie.frameclk;
    return !pmore_wait_key(&dv, 1);
    }
}

#define MOVIECMD_SKIP_ALL(p,end) \
    while (p < end && *p && *p != '\n') \
    { p++; } \

unsigned char *
mf_movieProcessCommand(unsigned char *p, unsigned char *end)
{
    for (; p < end && *p != '\n'; p++)
    {
    if (*p == 'S') {
        // SYNCHRONIZATION
        gettimeofday(&mfmovie.synctime, NULL);
        // S can take other commands
    } 
    else if (*p == 'E') 
    {
        // END
        STOP_MOVIE();
        // MFDISP_SKIPCURLINE();
        MOVIECMD_SKIP_ALL(p,end);
        return p;
    }
    else if (*p == 'P') 
    {
        // PAUSE
        mfmovie.pause = 1;
        // MFDISP_SKIPCURLINE();
        MOVIECMD_SKIP_ALL(p,end);
        return p;
 
    }
    else if (*p == 'G') 
    {
        // GOTO
        // Gt+-n
        // jump +-n of type(l,p,f)

        mf_movieExecuteOffsetCmd(p+1, end); 
        MOVIECMD_SKIP_ALL(p,end);
        return p;
    } 
    else if (*p == ':') 
    {
        // NAMED
        // :name:
        // name allows alnum only
        p++;
        // TODO check isalnum p?
        
        // :name can accept trailing commands
        while (p < end && *p != '\n' && *p != ':')
        p++;

        if (*p == ':') p++;

        // continue will increase p
        p--;
        continue;
    }
    else if (*p == 'K') 
    {
        // Reserve Key for interactive usage.
        // Currently only K#...# format is supported.
        if (p+2 < end && *(p+1) == '#')
        {
        p += 2;
        mfmovie.optkeys = p;
        mfmovie.interactive = 1;

        // K#..# can accept trailing commands
        while (p < end && *p != '\n' && *p != '#')
            p++;

        // if empty, set optkeys to NULL?
        if (mfmovie.optkeys == p)
            mfmovie.optkeys = NULL;

        if (*p == '#') p++;

        // continue will increase p
        p--;
        continue;
        }
        MOVIECMD_SKIP_ALL(p,end);
        return p;
    }
    else if (*p == '#') 
    {
        // OPTIONS
        // #key1,frame1,text1#key2,frame2,text2#
        mfmovie.options = p+1;
        mfmovie.interactive = 1;
        // MFDISP_SKIPCURLINE();
        MOVIECMD_SKIP_ALL(p,end);
        return p;
    }
    else if (*p == 'O') 
    {
        // OLD compatible mode
        // =  -> compat24
        // -  -> ?
        // == -> ?
        p++;
        if (p >= end)
        return end;
        if (*p == '=')
        {
        mfmovie.mode = MFDISP_MOVIE_PLAYING_OLD;
        mfmovie.compat24 = 1;
        p++;
        }
        // MFDISP_SKIPCURLINE();
        return p+1;
    } 
    else if (*p == 'L') 
    {
        // LOOP
        // Lm,n   
        // m times to backward n
        break;
    } 
    else 
    {
        // end of known control codes
        break;
    }
    }
    return p;
}

int 
mf_movieNextFrame()
{
    while (1) 
    {
    unsigned char *p = mf_movieFrameHeader(mf.disps, mf.end);

    if(p) 
    {
        float nf = 0;
        unsigned char *odisps = mf.disps;
        
        /* process leading */
        p = mf_movieProcessCommand(p, mf.end);

        // disps may change after commands
        if (mf.disps != odisps)
        {
        // commands changing location must
        // support at least one frame pause
        // to allow user break
        struct timeval tv;
        mf_float2tv(MOVIE_MIN_FRAMECLK, &tv);

        if (pmore_wait_key(&tv, 0))
        {
            STOP_MOVIE();
            return 0;
        }
        continue;
        }

        /* process time */
        if (mf_str2float(p, mf.end, &nf))
        {
        mf_float2tv(nf, &mfmovie.frameclk);
        }

        if(mfmovie.synctime.tv_sec > 0)
        {
        mfmovie.synctime.tv_usec += mfmovie.frameclk.tv_usec;
        mfmovie.synctime.tv_sec  += mfmovie.frameclk.tv_sec;
        mfmovie.synctime.tv_sec  += mfmovie.synctime.tv_usec / MOVIE_SECOND_U;
        mfmovie.synctime.tv_usec %= MOVIE_SECOND_U;
        }

        if (mfmovie.mode != MFDISP_MOVIE_PLAYING_OLD)
        mf_forward(1);

        return 1;
    }

    if (mf_forward(1) <= 0)
        break;
    }

    return 0;
}
#endif

/* vim:sw=4:ts=8:nofoldenable
 */