/*
    xed - Simple hex editor

    Copyright (C) 2005  Ian Cowburn (ianc@noddybox.demon.co.uk)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    -------------------------------------------------------------------------

*/
static const char id[]="$Id$";

#include <sys/types.h>
#include <curses.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <ctype.h>
#include <signal.h>
#include <stdarg.h>
#include <regex.h>
#include <string.h>

#include "xedkeys.h"

#define	VERSION		"V2.0"
#define USAGE		"[-x] [-i] [-r] [-c] [-R] file"

#define NONE		0
#define HEX		1
#define ASCII		2
#define REGEXP		3

#define FILENAME_LEN	25

#define GETSTR_LEN	80
#define GETSTR_DISP_LEN	50

#define BUFSIZE(x)	((((x)/1024)+1)*1024)

#define CTYPE(func,c)   (((c>=0)&&(c<=255)) ? func(c) : (c))
#define CTEST(func,c)   (((c>=0)&&(c<=255)) ? func(c) : (FALSE))

#define IPBUFFSIZE	1024

typedef unsigned char	uchar;

char	*name;
char	*filename;
char	print_name[FILENAME_LEN+1];
uchar	*edit;
uchar	*mirror;
long	bufsize;
int	in_place=FALSE;
int	regexp=FALSE;
int	casesense=TRUE;
int	readonly=FALSE;
int	fd;
long	file_len;
long	page_ptr;
long	file_ptr;
long	end_page;
long	page_depth;
int	edit_hex=TRUE;
int	overtype=TRUE;
int	editted=FALSE;

int	last_search=NONE;
char	sch_str[GETSTR_LEN];
int	sch_hex[128];
int	sch_no;

regex_t	re;
int	re_alloc=FALSE;

/* Function prototypes
*/
void	Err(const char *s);
void	SysErr(const char *p);
void	MainCode(void);
int	HandleKey(int key);
int	HandleKeyHex(int key);
void	HandleKeyAscii(int key);
int	CompileRegExp(void);
void	SearchRegExp(void);
void	DoSearchRegExp(void);
void	SearchString(void);
void	DoSearchString(void);
void	SearchHex(void);
void	DoSearchHex(void);
int	Read(int fd, void *buff, int no);
int	Write(int fd, void *buff, int no);
void	OpenFile(void);
void	SaveFile(void);
int	CalcHex(int x[]);
int	GetByte(long cur);
char	*GetByteString(long *cur, int all_lower);
int	GetLastSaved(long cur);
void	Display(void);
void	PartialDisplay(long cur, int x, int y);
void	InsertValue(long p,long b);
void	DeleteValue(long p);
void	ReplaceValue(long p,long b);
void	UpdateValue(long p, int b);
void	ShowCursor(void);
void	ShowPos(void);
int	ScanKey(void);
int	GetKey(int allkeys);
void	GetString(char s[]);
char	*Get(char *p);
int	GetChar(char *p, char *v);
void	Message(const char *fmt, ...);
char	*Tail(char s[], int l);


int main(int argc, char *argv[])
{
    char *env,*arg,*list[256];	/* If you're that prepared to break it, you */
    int listc;			/* DESERVE to get a segmentation fault */
    int src,dest,f;

    name=argv[0];

    /* Prepend XEDARG variable if present
    */
    src=0;
    dest=0;
    if (env=getenv("XEDARG"))
    {
	arg=strtok(env," \t");

	while(arg)
	{
	    list[dest++]=arg;
	    arg=strtok(NULL," \t");
	}
    }

    for(f=1;f<argc;f++)
    	list[dest++]=argv[f];

    listc=dest;

    if (listc<1)
    {
        fprintf(stderr,"%s:usage %s %s\n",name,name,USAGE);
        exit(EXIT_FAILURE);
    }

    f=0;
    while(*list[f]=='-')
    {
	switch (*(list[f]+1))
	{
	    case 'x':
		in_place=TRUE;
		break;
	    case 'i':
		overtype=FALSE;
		break;
	    case 'r':
		regexp=TRUE;
		break;
	    case 'c':
		casesense=FALSE;
		break;
	    case 'R':
		readonly=TRUE;
		break;
	    default:
		fprintf(stderr,"%s:usage %s %s\n",name,name,USAGE);
		exit(EXIT_FAILURE);
		break;
	}
	f++;

	if (f==listc)
	{
	    fprintf(stderr,"%s:usage %s %s\n",name,name,USAGE);
	    exit(EXIT_FAILURE);
	}
    }

    filename=list[f];

    strcpy(print_name,Tail(filename,FILENAME_LEN));

    signal(SIGINT,SIG_IGN);

    initscr();
    cbreak();
    noecho();
    keypad(stdscr,TRUE);

    MainCode();

    erase();
    refresh();

    if (in_place)
        if (close(fd)==-1)
            SysErr(filename);

    endwin();

    return EXIT_SUCCESS;
}


void Err(const char *s)
{
    endwin();

    fprintf(stderr,"%s: %s\n",name,s);
    exit(EXIT_FAILURE);
}


void SysErr(const char *p)
{
    endwin();

    if (p)
	perror(p);
    else
	perror(name);

    exit(EXIT_FAILURE);
}


void MainCode(void)
{
    char errstr[80];
    int quit=FALSE;
    int ch;

    if (COLS<80)
    {
	sprintf
	    (errstr,
		"Terminal width (%d) less than required minimum (80)",COLS);
        Err(errstr);
    }

    if (LINES<10)
    {
	sprintf
	    (errstr,
		"Terminal depth (%d) less than required minimum (10)",LINES);
        Err(errstr);
    }

    OpenFile();

    file_ptr=page_ptr=0L;

    Display();

    Message(VERSION);
    ShowCursor();

    while(!quit)
    {
        switch (HandleKey(GetKey(TRUE)))
	{
            case FALSE:
                if ((editted)&&(!in_place))
		{
                    ch=GetChar
                        ("File has been editted.  Quit (y/[n])?","yYnN\n");

                    if ((ch=='y')||(ch=='Y'))
                        quit=TRUE;
		}
                else
                    quit=TRUE;

                break;
            case TRUE:
                break;
	}
    }
}


int HandleKey(int key)
{
    int finished;

    if (edit_hex)
    {
        HandleKeyHex(key);
        return ((key!='q')&&(key!='Q')&&(key!=3));
    }
    else
    {
        HandleKeyAscii(key);
        return (key!=3);
    }
}


int HandleKeyHex(int key)
{
    char *s;
    int hex[2],next_key,old_val;
    int ch;

    switch(key)
    {
        case CURS_UP1:
        case CURS_UP2:
            if (file_ptr>15)
	    {
                file_ptr-=16;

                if (file_ptr<page_ptr)
		{
                    page_ptr-=16;

                    if (page_ptr<0)
                        page_ptr=0;

                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case CURS_LEFT1:
        case CURS_LEFT2:
            if (file_ptr)
	    {
                file_ptr--;

                if (file_ptr<page_ptr)
		{
                    page_ptr-=16;

                    if (page_ptr<0)
                        page_ptr=0;

                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case CURS_DOWN1:
        case CURS_DOWN2:
        case '\n':
            if (file_ptr<(file_len-1))
	    {
                file_ptr+=16;

		if (file_ptr>(file_len-1))
		    file_ptr=file_len-1;

                if (file_ptr>end_page)
		{
                    page_ptr+=16;
                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case CURS_RIGHT1:
        case CURS_RIGHT2:
            if (file_ptr<(file_len-1))
	    {
                file_ptr++;

                if (file_ptr>end_page)
		{
                    page_ptr+=16;
                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case PAGE_BACK1:
        case PAGE_BACK2:
        case PAGE_BACK3:
            if (file_ptr>=page_depth)
	    {
                page_ptr-=page_depth;

                if (page_ptr<0)
                    page_ptr=0;

                file_ptr-=page_depth;

                Display();
	    }
            break;

        case PAGE_FWD1:
        case PAGE_FWD2:
        case PAGE_FWD3:
            if (page_ptr<=file_len-page_depth-1)
	    {
                page_ptr+=page_depth;

                file_ptr+=page_depth;

		if (file_ptr>(file_len-1))
		    file_ptr=file_len-1;

                Display();
	    }
            break;

        case SWITCH_TO_ASCII:
            edit_hex=FALSE;
            ShowCursor();
            break;

        case START_OF_FILE:
            page_ptr=file_ptr=0L;
            Display();
            break;

        case END_OF_FILE:
            page_ptr=file_len-page_depth;

            if (page_ptr<0)
                page_ptr=0;

            file_ptr=file_len-1;
            Display();
            break;

        case JUMP_TO:
            s=Get("Address to jump to (prefix with 0x for hex) : ");

            page_ptr=strtol(s,(char **)NULL,0);

            if (page_ptr<0)
                page_ptr=0;

            if (page_ptr>=file_len)
                page_ptr=file_len-1;

            file_ptr=page_ptr;

            if ((page_ptr>file_len-page_depth)&&(page_depth<file_len))
	    {
                page_ptr=file_len-page_depth;

                if (page_ptr<0)
                    page_ptr=0;
	    }

            Display();

            break;

        case SAVE:
	    if (!readonly)
	    {
		if (!in_place)
		{
		    SaveFile();

		    editted=FALSE;
		}
		else
		    Message("All changes already saved in -x mode!");
	    }
	    else
		Message("File is read-only!");

            ShowCursor();
            break;

        case RESTORE_BYTE:
	    if (!readonly)
	    {
		if (!in_place)
		{
		    if (file_len)
		    {
			ReplaceValue
				(file_ptr,(uchar)GetLastSaved(file_ptr));

			if (file_ptr<(file_len)-1)
			{
			    file_ptr++;

			    if (file_ptr>end_page)
			    {
				page_ptr+=16;
				Display();
			    }
			    else
				ShowCursor();
			}
		    }
		}
		else
		    Message("Can't recover in -x mode!");
	    }
	    else
		Message("File is read-only!");

            ShowCursor();
            break;

        case REFRESH:
            Display();
            break;

        case INSERT_TOGGLE:
	    if (!readonly)
		if (in_place)
		{
		    Message("no insert/delete in -x mode");
		    ShowCursor();
		}
		else
		{
		    overtype=!overtype;
		    ShowPos();
		    ShowCursor();
		}
            break;

        case DELETE_CHAR:
	    if (!readonly)
	    {
		if (in_place)
		    Message("no insert/delete in -x mode");
		else
		    if (file_len)
		    {
			editted=TRUE;

			DeleteValue(file_ptr);

			if ((file_ptr>=file_len)&&(file_len))
			    if (--file_ptr<page_ptr)
				page_ptr=file_ptr;

			Display();
		    }
	    }
	    else
		Message ("File is read-only!");

	    ShowCursor();
            break;

        case FIND_STRING:
	    if (!regexp)
	    {
		ch=GetChar("(S)tring or (N)umber search ? ","sSnN\n");

		if ((ch=='N')||(ch=='n'))
		{
		    SearchHex();
		    Display();
		}
		else
		{
		    if ((ch=='S')||(ch=='s'))
		    {
			SearchString();
			Display();
		    }
		    else
			ShowCursor();
		}
	    }
	    else
	    {
		SearchRegExp();

		if (last_search==REGEXP)
		    Display();
		else
		    ShowCursor();
	    }

            break;

        case FIND_NEXT:
	    switch (last_search)
	    {
            	case NONE:
		    Message("No previous search!");
		    ShowCursor();
                    break;
                case HEX:
                    DoSearchHex();
                    Display();
                    break;
                case ASCII:
		    DoSearchString();
		    Display();
                    break;
		case REGEXP:
		    DoSearchRegExp();
		    Display();
                    break;
	    }
            break;

	case FIND_TYPE:
	    regexp=!regexp;
            ShowCursor();
	    break;

	case FIND_CASE:
	    casesense=!casesense;

	    if (last_search==REGEXP)
		CompileRegExp();

            ShowCursor();
	    break;

        default:
	    if (!readonly)
	    {
		if (CTEST(isxdigit,key))
		{
		    old_val=GetByte(file_ptr);

		    hex[0]=CTYPE(toupper,key);

		    addch(hex[0]);
		    refresh();

		    next_key=GetKey(FALSE);

		    while ((!CTEST(isxdigit,next_key))&&
				    (next_key!=8)&&(next_key!=127))
			next_key=GetKey(FALSE);

		    hex[1]=CTYPE(toupper,next_key);

		    if (CTEST(isxdigit,next_key))
		    {
			editted=TRUE;

			UpdateValue(file_ptr,CalcHex(hex));

			/* Special case for the first char in an empty file */
			if (file_len==0)
			    file_len=1;

			if (file_ptr<(file_len)-1)
			{
			    file_ptr++;

			    if (file_ptr>end_page)
			    {
				page_ptr=file_ptr;
				Display();
			    }
			    else
				ShowCursor();
			}
			else
			    ShowCursor();
		    }
		    else
		    {
			if (!overtype)
			    ReplaceValue(file_ptr,old_val);
			else
			    UpdateValue(file_ptr,old_val);

			ShowCursor();
		    }
		}
	    }
            break;
    }
}


void HandleKeyAscii(int key)
{
    switch(key)
    {
        case ASC_CURS_UP1:
        case ASC_CURS_UP2:
            if (file_ptr>15)
	    {
                file_ptr-=16;

                if (file_ptr<page_ptr)
		{
                    page_ptr-=16;

                    if (page_ptr<0)
                        page_ptr=0;

                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case ASC_CURS_LEFT1:
        case ASC_CURS_LEFT2:
            if (file_ptr)
	    {
                file_ptr--;

                if (file_ptr<page_ptr)
		{
                    page_ptr-=16;

                    if (page_ptr<0)
                        page_ptr=0;

                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case ASC_CURS_DOWN1:
        case ASC_CURS_DOWN2:
            if (file_ptr<(file_len-1))
	    {
                file_ptr+=16;

		if (file_ptr>(file_len-1))
		    file_ptr=file_len-1;

                if (file_ptr>end_page)
		{
                    page_ptr+=16;
                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case ASC_CURS_RIGHT1:
        case ASC_CURS_RIGHT2:
            if (file_ptr<(file_len)-1)
	    {
                file_ptr++;

                if (file_ptr>end_page)
		{
                    page_ptr+=16;
                    Display();
		}
                else
                    ShowCursor();
	    }
            break;

        case ASC_PAGE_BACK:
            if (file_ptr>=page_depth)
	    {
                page_ptr-=page_depth;

                if (page_ptr<0)
                    page_ptr=0;

                file_ptr-=page_depth;

                Display();
	    }
            break;

        case ASC_PAGE_FWD:
            if (page_ptr<=file_len-page_depth-1)
	    {
                page_ptr+=page_depth;

                file_ptr+=page_depth;

		if (file_ptr>(file_len-1))
		    file_ptr=file_len-1;

                Display();
	    }
            break;

        case ASC_REFRESH:
            Display();
            break;

        case SWITCH_TO_HEX:
            edit_hex=TRUE;
            ShowCursor();
            break;

        case INSERT_TOGGLE:
	    if (!readonly)
		if (in_place)
		{
		    Message("no insert/delete in -x mode");
		    ShowCursor();
		}
		else
		{
		    overtype=!overtype;
		    ShowPos();
		    ShowCursor();
		}
            break;

        case ASC_DELETE_CHAR:
	    if (!readonly)
	    {
		if (in_place)
		    Message("no insert/delete in -x mode");
		else
		    if (file_len)
		    {
			DeleteValue(file_ptr);

			if ((file_ptr>=file_len)&&(file_len))
			    if (--file_ptr<page_ptr)
				page_ptr=file_ptr;

			Display();
		    }
	    }
	    else
		Message ("File is read-only!");

	    ShowCursor();
            break;

        default:
	    if (!readonly)
		if (CTEST(isprint,key))
		{
		    editted=TRUE;

		    UpdateValue(file_ptr,key);

		    /* Special case for the first char in an empty file */
		    if (file_len==0)
			file_len=1;

		    if (file_ptr<(file_len)-1)
		    {
			file_ptr++;

			if (file_ptr>end_page)
			{
			    page_ptr=file_ptr;
			    Display();
			}
			else
			    ShowCursor();
		    }
		    else
			ShowCursor();
		}
            break;
    }
}

int CompileRegExp(void)
{
    char buff[80];
    int ret;

    if (re_alloc)
	regfree(&re);

    re_alloc=FALSE;

    if (casesense)
	ret=regcomp(&re,sch_str,REG_EXTENDED|REG_NEWLINE);
    else
	ret=regcomp(&re,sch_str,REG_EXTENDED|REG_ICASE|REG_NEWLINE);

    if(ret!=0)
    {
	regerror(ret,&re,buff,80);
	Message ("RE error : %s",buff);
	return (FALSE);
    }

    re_alloc=TRUE;

    return TRUE;
}

void SearchRegExp(void)
{
    last_search=NONE;

    strcpy(sch_str,Get("/"));

    if (!strlen(sch_str))
        return;

    if (CompileRegExp())
    {
	last_search=REGEXP;
	DoSearchRegExp();
    }
}

void DoSearchRegExp(void)
{
    char *p;
    long f,of;
    regmatch_t re_match;

    Message("Searching....");

    f=file_ptr+1;

    of=f;
    p=GetByteString(&f,!casesense);
    while(p)
    {
	if (regexec(&re,p,1,&re_match,0)==0)
	{
	    file_ptr=of+re_match.rm_so;

	    if ((file_ptr<page_ptr)||(file_ptr>end_page))
		page_ptr=file_ptr;

	    free(p);
	    return;
	}

	free(p);
	of=f;
	p=GetByteString(&f,!casesense);
    }

    Message("Not found.  Press a key.");
    GetKey(TRUE);
    Message("");
}


void SearchString(void)
{
    last_search=NONE;

    strcpy(sch_str,Get("Search string : "));

    if (!strlen(sch_str))
        return;

    last_search=ASCII;

    DoSearchString();
}


void DoSearchString(void)
{
    long f;
    int l,r;

    Message("Searching....");

    l=strlen(sch_str);

    for(f=file_ptr+1;f<file_len-l+1;f++)
    {
        for(r=0;r<l;r++)
	    if (casesense)
	    {
		if (GetByte(f+r)!=sch_str[r])
		    r=l+1;
	    }
	    else
	    {
		if (tolower(GetByte(f+r))!=tolower(sch_str[r]))
		    r=l+1;
	    }

        if (r==l)
	{
            file_ptr=f;

            if ((file_ptr<page_ptr)||(file_ptr>end_page))
                page_ptr=file_ptr;

            return;
	}
    }

    Message("Not found.  Press a key.");
    GetKey(TRUE);
    Message("");
}


void SearchHex(void)
{
    char *s;

    last_search=NONE;
    sch_no=0;

    s=Get("Enter First number (return to quit) : ");

    while(*s)
    {
        sch_hex[sch_no++]=(int)strtol(s,(char **)NULL,0);
        s=Get("Enter next number (return to finish) : ");
    }

    if (!sch_no)
        return;

    last_search=HEX;

    DoSearchHex();
}


void DoSearchHex(void)
{
    int f,r;

    Message("Searching....");

    for(f=file_ptr+1;f<file_len-sch_no+1;f++)
    {
        for(r=0;r<sch_no;r++)
            if (GetByte(f+r)!=sch_hex[r])
                r=sch_no+1;

        if (r==sch_no)
	{
            file_ptr=f;

            if ((file_ptr<page_ptr)||(file_ptr>end_page))
                page_ptr=file_ptr;

            return;
	}
    }

    Message("Not found.  Press a key");
    GetKey(TRUE);
    Message("");
}


/* Provide a skin to read(2) and write(2)
*/
int Read(int fd, void *buff, int no)
{
    int tot,rd;

    tot=0;
    while(tot<no)
    {
	rd=read(fd,buff+tot,no-tot);

	/* If we read zero bytes, it's probably the end of the file.
	*/
	if (rd==0)
	    return tot;

	/* Reading -1 leaves little room for argument!
	*/
	if (rd==-1)
	    return -1;

	tot+=rd;
    }

    return tot;
}


int Write(int fd, void *buff, int no)
{
    int tot,wr;

    tot=0;
    while(tot<no)
    {
	wr=write(fd,buff+tot,no-tot);

	if ((wr==-1)||(wr==0))
	    return -1;

	tot+=wr;
    }

    return tot;
}


void OpenFile(void)
{
    if (readonly)
    {
	if ((fd=open(filename,O_RDONLY))==-1)
	    SysErr(filename);
    }
    else
    {
	if ((fd=open(filename,O_RDWR))==-1)
	    SysErr(filename);
    }

    if ((file_len=lseek(fd,0L,SEEK_END))==-1)
	SysErr(filename);

    lseek(fd,0L,SEEK_SET);

    if (!in_place)
    {
        if (!(edit=(uchar *)malloc(bufsize=BUFSIZE(file_len))))
            SysErr(NULL);

        if (!(mirror=(uchar *)malloc(bufsize)))
            SysErr(NULL);

        if (Read(fd,edit,file_len)!=file_len)
            SysErr(filename);

        memcpy(mirror,edit,file_len);

        close(fd);
    }
}


void SaveFile(void)
{
    Message("Writing...");

    if((fd=open(filename,O_WRONLY|O_TRUNC))==-1)
        SysErr(filename);

    if (Write(fd,edit,file_len)!=file_len)
        SysErr(filename);

    close(fd);

    memcpy(mirror,edit,file_len);

    Message("Done");
}


int CalcHex(int x[])
{
    static char hex_digits[]="0123456789ABCDEF";

    int h,l;

    for(h=0;(h<16)&&(x[0]!=hex_digits[h]);h++);
    for(l=0;(l<16)&&(x[1]!=hex_digits[l]);l++);

    if ((h==16)||(l==16))
        Err("CalcHex() broken!");

    return(h*16+l);
}


int GetByte(long cur)
{
    static uchar ipbuff[IPBUFFSIZE];
    static long buffpos;
    static int first_read=TRUE;
    uchar c;

    if (cur>=file_len)
        return -1;

    if(!in_place)
        return edit[cur];

    if (first_read)
	first_read=FALSE;
    else
	if ((cur>=buffpos)&&(cur<buffpos+IPBUFFSIZE))
	    return ipbuff[cur-buffpos];

    if (lseek(fd,cur,SEEK_SET)==-1)
    	SysErr(filename);

    if(Read(fd,ipbuff,IPBUFFSIZE)==-1)
        SysErr(filename);

    buffpos=cur;

    return ipbuff[cur-buffpos];
}


char *GetByteString(long *cur, int all_lower)
{
    char *p;
    long l,cp;
    int b;

    cp=*cur;

    if (cp>=file_len)
        return NULL;

    l=0;

    while(((b=GetByte(cp++))!=-1)&&(b!=0)&&(b!='\n'))
	l++;

    if (!l)
    {
	if (!(p=(char *)malloc(0x1)))
	    SysErr(NULL);
	*p=0;
	*cur+=1;
	return p;
    }

    if (!(p=(char *)malloc((int)l+1)))
	SysErr(NULL);

    for(cp=0;cp<l;cp++)
	*(p+cp)=(all_lower) ? (tolower(GetByte((*cur)+cp))) :
					    (GetByte((*cur)+cp));

    *(p+cp)=0;

    *cur+=l+1;

    return p;
}


int GetLastSaved(long cur)
{
    return (int)mirror[cur];
}


void Display(void)
{
    int r,f,b;
    long cur;

    erase();

    mvprintw(0,0,"File : %s",print_name);

    r=3;
    cur=page_ptr;

    while(r<LINES-3)
    {
        mvprintw(r,0,"%8.8X :",cur);

        for(f=0;f<16;f++)
            if ((b=GetByte(cur++))==-1)
                mvaddstr(r,11+f*3,"**");
            else
	    {
                mvprintw(r,11+f*3,"%2.2X",(uchar)b);

                if ((b<32)||(b>126))
                    mvaddch(r,62+f,(chtype)'.');
                else
                    mvaddch(r,62+f,(chtype)b);
	    }
        r++;
    }

    end_page=cur-1;
    page_depth=end_page-page_ptr+1;

    ShowCursor();
}


void PartialDisplay(long cur, int x, int y)
{
    int r,f,b;

    r=y;

    while(r<LINES-3)
    {
        if (!x)
            mvprintw(r,0,"%8.8X :",cur);

        for(f=x;f<16;f++)
            if ((b=GetByte(cur++))==-1)
                mvaddstr(r,11+f*3,"**");
            else
	    {
                mvprintw(r,11+f*3,"%2.2X",(uchar)b);

                if ((b<32)||(b>126))
                    mvaddch(r,62+f,(chtype)'.');
                else
                    mvaddch(r,62+f,(chtype)b);
	    }

        x=0;
        r++;
    }
}


void InsertValue(long p,long b)
{
    if (++file_len>bufsize)
        {
        if (!(edit=(uchar *)realloc(edit,(bufsize=BUFSIZE(file_len)))))
            SysErr(NULL);

        if (!(mirror=(uchar *)realloc(mirror,bufsize)))
            SysErr(NULL);
        }

    memmove(edit+p+1,edit+p,file_len-p-1);
    memmove(mirror+p+1,mirror+p,file_len-p-1);

    edit[p]=(uchar)b;
    mirror[p]=(uchar)b;
}


void DeleteValue(long p)
{
    if (file_len>1)
    {
        memmove(edit+p,edit+p+1,file_len-p-1);
        memmove(mirror+p,mirror+p+1,file_len-p-1);

        file_len--;
    }
    else
        file_len=0;
}


void ReplaceValue(long p,long b)
{
    int x,y;
    uchar c=b;

    edit[p]=(uchar)b;

    y=3+(p-page_ptr)/16;
    x=(p-page_ptr)%16;

    mvprintw(y,11+x*3,"%2.2X",(uchar)b);

    if ((b<32)||(b>126))
        mvaddch(y,62+x,(chtype)'.');
    else
        mvaddch(y,62+x,(chtype)b);
}


void UpdateValue(long p, int b)
{
    int x,y;
    uchar c=b;

    if (!in_place)
    {
        if (overtype)
            edit[p]=(uchar)b;
        else
            InsertValue(p,b);
    }
    else
    {
        lseek(fd,p,SEEK_SET);
        if (Write(fd,&c,1)==-1)
            SysErr(filename);
    }

    y=3+(p-page_ptr)/16;
    x=(p-page_ptr)%16;

    if (overtype)
    {
        mvprintw(y,11+x*3,"%2.2X",(uchar)b);

        if ((b<32)||(b>126))
            mvaddch(y,62+x,(chtype)'.');
        else
            mvaddch(y,62+x,(chtype)b);
    }
    else
        PartialDisplay(p,x,y);
}


void ShowCursor(void)
{
    int x,y;

    ShowPos();

    y=(file_ptr-page_ptr)/16;
    x=(file_ptr-page_ptr)%16;

    if (edit_hex)
        move(3+y,11+x*3);
    else
        move(3+y,62+x);

    refresh();
}


void ShowPos(void)
{
    mvprintw(1,0,"Pos : %8.8x",file_ptr);
    mvprintw(0,40,"File size : %8.8x",file_len);

    /* Print Status line */
    if (readonly)
	mvaddstr(1,20,"READ ONLY");
    else
	if (overtype)
	    mvaddstr(1,20,"OVERTYPE");
	else
	    mvaddstr(1,20," INSERT ");

    if (regexp)
        mvaddstr(1,37,"REGEXP SEARCH");
    else
        mvaddstr(1,37,"STRING SEARCH");

    if (casesense)
	mvaddstr(1,57," CASE SENSITIVE ");
    else
	mvaddstr(1,57,"CASE INSENSITIVE");
}


int ScanKey(void)
{
    int k;

    k=getch();

    if (k==KEY_BACKSPACE)
	k=8;

    if (k==ERR)
	k=3;

    /* Message("Read key %9d",k); */

    return k;
}


int GetKey(int allkeys)
{
    int k;

    k=ScanKey();

    if (!allkeys)
	while(!CTEST(isascii,k))
	    k=ScanKey();

    return k;
}


void GetString(char s[])
{
    int k,done,p,x,y;

    done=FALSE;
    p=0;
    s[p]=0;
    getyx(stdscr,y,x);

    while(!done)
    {
	mvprintw(y,x,"%-*.*s",GETSTR_DISP_LEN,GETSTR_DISP_LEN,
						Tail(s,GETSTR_DISP_LEN));

	move(y,x+((p>=GETSTR_DISP_LEN) ? (GETSTR_DISP_LEN) : (p)));

	refresh();

	switch (k=GetKey(TRUE))
	{
	    case 8:
	    case 127:
		if (p)
		    s[--p]=0;
		break;

	    case 3:
		strcpy(s,"");
		done=TRUE;
		break;

	    case '\n':
		done=TRUE;
		break;

	    default:
		if (p<GETSTR_LEN-1)
		{
		    s[p++]=(char)k;
		    s[p]=0;
		}
		else
		    flash();
	}
    }
}


char *Get(char *p)
{
    static char s[GETSTR_LEN];
    int f;

    Message(p);

    echo();
    GetString(s);
    noecho();

    return s;
}


int GetChar(char *p, char *v)
{
    int f,ch=0xff;

    Message(p);

    while(!strchr(v,ch))
        ch=GetKey(TRUE);

    ShowCursor();

    return ch;
}


void Message(const char *fmt, ...)
{
    va_list arg;
    int f;

    move(LINES-1,0);

    for(f=0;f<COLS-2;f++)
        addch(' ');

    va_start(arg,fmt);
    mvwprintw(stdscr,LINES-1,0,fmt,arg);
    va_end(arg);

    refresh();
}


char *Tail(char s[], int l)
{
    static char ret[1024];
    int sl,d;

    if(strlen(s)<=l)
        strcpy(ret,s);
    else
        {
        sl=strlen(s);
        d=l;

        while(d>-1)
            ret[d--]=s[sl--];

	ret[0]='.';
	ret[1]='.';
        }

    return ret;
}


/* END OF FILE */