#include <cstdlib>
#include <iostream>
#include <windows.h>
//#include <winnt.h>

using namespace std;
bool bQuit;
FILE * fp;
void ShowHelpInfo();
void GetCommand(char * commands);
void CheckCommand(char * commands);
bool GetOpenFileHandle(char * path);
bool ShowFileHexData(int lowrange,int highrange);
void show(unsigned char * showdata,int cha,long lowrange);
int main(int argc, char *argv[])
{

    char compt[10];
    char command[100];
    fp=0;
    //sprintf("-",compt);
    bQuit=1;
    ShowHelpInfo();
    // show();system("PAUSE");
    while (bQuit)
    {
        printf("-");
        scanf("%c",command);
        CheckCommand(command);
    }
    //  system("PAUSE");
    return EXIT_SUCCESS;
}
void ShowHelpInfo()
{
    char showstr[]="File Hex for Dos Version write by Chjshen.\n                              2009-05-21\n\n";
    printf(showstr);
    printf("Open  -f [filename]  |open Filename file.\n");
    printf("Show  -s [range]     |show hex data. \n");
    printf("Quit  -q             |quit.\n");
    printf("Hex   -h  Hex1 hex2  |Hex1+Hex2 and Hex1-Hex2 or Hex2-Hex1.\n");
    printf("Help  -?             |help information.\n");
    printf("\nFor Example:\n -f notepad.exe \n -s 100 15f \n -h 10 12 \n");

}
void CheckCommand(char * commands)
{
    char command;
    char hexresultstr[100];
    char path[MAX_PATH];
    int hex1,hex2;
    int lowrange,highrange;
    command=commands[0];

    switch (toupper(command))
    {
    case 'F':
        scanf("%s",path);
        if (GetOpenFileHandle(path))
            printf("Now \"%s\" is opened.",path);
        fflush(stdin);
        break;
    case 'E':
    case 'Q':
        if (fp!=0)
            fclose(fp);
        printf("quit.");
        bQuit=0;
        fflush(stdin);
        break;
    case 'S':
        scanf("%x %x",&lowrange,&highrange);
        ShowFileHexData(lowrange,highrange);
        //printf("Show hex data.");
        fflush(stdin);
        break;
    case 'H':
        scanf("%X %X",&hex1,&hex2);
        sprintf(hexresultstr,"%04X %04X",hex1+hex2,hex1>=hex2?hex1-hex2:hex2-hex1);
        printf(hexresultstr);
        fflush(stdin);
        break;
    case '?':
        ShowHelpInfo();
        fflush(stdin);
        break;
    case 10:
        fflush(stdin);
        break;
    default:
        fflush(stdin);
        printf("Error command line.");
    }
    printf("\n");
}
bool GetOpenFileHandle(char * path)
{
    if (strlen(path)==0)
    {
        scanf("%s",path);
    }
    if (fp!=0)
    {
        fclose(fp);
    }
    fp=fopen(path,"rb");

    if (fp==0)
    {
        printf("Open File Error,please check your enter's filename is vaild.");
    }
    else
    {
        return true;
    }

    return 0;
}
bool ShowFileHexData(int lowrange,int highrange)
{

    long temlength=0;
    if (fp==0)
    {
        printf("No file opened,please open file that you wanted to show hex data.");
        return 0;
    }
    long length;
    fseek(fp,0,SEEK_END);
    length=ftell(fp);
    if (highrange>length||lowrange>length)
    {
        printf("over file length.");
        return 0;
    }
    if (lowrange>=highrange)
    {
        printf("Range error,please enter correct hex number.");
        return 0;
    }
    printf("%X~%X  Hex Data:\n",lowrange,highrange);
    // printf("%02X",readdata);
    int totall=lowrange;
    int i;
    int cha=highrange-lowrange;
    i=0;

    unsigned char * temdata=(unsigned char*)malloc(cha+1);
    fseek(fp,lowrange,SEEK_SET);
    fread(temdata,sizeof(unsigned char),cha+1,fp);
    cha++;
    show(temdata,cha,lowrange);

    free(temdata);
    return 1;
}
void show(unsigned char * showdata,int cha,long lowrange)
{
    int j,i;
    i=0;
    char readdata[100]="";
    j=0;
    char asii[20]="";
    while (j<=(int)cha/16)
    {
        i=0;
        sprintf(readdata,"");
        sprintf(asii,"");
        printf("\n%08X:",lowrange+j*16);
        do
        {
            if (j*16+i<cha)
            {
                if (i%16==8)
                    printf("-");
                else
                    printf(" ");
                printf("%02X",showdata[j*16+i]);
                if (showdata[j*16+i]<33||showdata[j*16+i]>127)
                {
                    if (showdata[j*16+i]=='\0')
                    {
                        sprintf(asii+strlen(asii)," ");
                    }
                    else
                    {
                        sprintf(asii+strlen(asii)," ");
                    }
                }
                else
                {
                    sprintf(asii+strlen(asii),"%c",showdata[j*16+i]);
                }
            }
            else
            {
                printf("   ");
                sprintf(asii+strlen(asii)," ");
            }
            i++;
        }
        while (i<16);
        printf(" %s",asii);
        j++;
    }

}