need Help! reading a binary file

Hi guys, I have question. I haven’t program in c++ in over 5 years last time I was programming I was learning the langrage in school. I now have jump back into programming in c++ and i am trying to make a program that would be able to read a binary file and get the data from it. so i can save it to a text file.

Code:

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This is how the data is structured.

------------------------------------------------
Size (Bytes)              Name                Type                Description
-------the structure of the file--------------------------------------------
  4                                  Signature          char[4]            File Signature ('logi') no terminating null
  4                                  version            uint32              File Format Version
  4                                  count              uint32              Number of entries that follow

Variable        entries
-----------------------------------------------------
1                      namelenth        uint8              Length of name
namelenth              name              char[]              name (nameLength characters) no terminating null
6                      id                uint8[6]            HEXVALUE 
8                FILETIME    FILETIME      100-nanosecond increments since January 1, 1601 (UTC). 64-bit integer
------------------------------------------------------------------------


here is a hex example of the file(paste it in to your hex editor and save it)
------------------------------------
6C6F676905000000010000000D5468697369737468656E616D65000A11F1D11160992BFCD425C901
------------------------------------

Lets break it down
----------------------------------------------------------

6C6F6769 = logi                                Signature
05000000 = 5                                    version
01000000 = 1                                    count
----------------------------------------------------------

0D = 13                                        namelenth
5468697369737468656E616D65 =  Thisisthename    name
000A11F1D111 = 000A11F1D111                    HEXVALUE  hex value of name
60992BFCD425C901 = 3:55:05 AM  10/4/2008        FILETIME
----------------------------------------------------------

Signature = logi
version = 5
count = 1
namelenth = 13
name = Thisisthename
HEXVALUE = 000A11F1D111
FILETIME = 3:55:05 AM  10/4/2008

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

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I can not change the format of the file it has already been set a long time ago.

I am not looking for anybody to do this program for me I am just trying to be point in the
Right direction.

By the way I don’t have access to visual studio.net IDE

Currently I am using the free IDE "Bloodshed Software - Dev-C++"

I need to make this program work with Linux and windows. windows whould be fine right now and it has to be in c/c++

Any help will be greatly appreciated. thank you.

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

Look into the FAQs on this website for examples of small programs that perform I/O.

So EXACTLY which part of the problem are you struggling with? How far have you got?

--
Mats

Quote:

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Originally Posted by Dino

Look into the FAQs on this website for examples of small programs that perform I/O.

---

Quote:

---

Originally Posted by matsp

So EXACTLY which part of the problem are you struggling with? How far have you got?

--
Mats

---

thank you Marsp and Dino for you reply.

i look in the FAQ about read and writing files and all over the internet(GOOGLE) but I'm not sure if I'm on the right track. here is the code i came up with.

Code:

---

#include <fstream>
#include <iostream>
using namespace std;

class Header                               
{
public:
        char  signature[4];                        //is logi
        unsigned int  version;                //greater than 5
        unsigned int  entries;                //number of entries
};

int main()
{
        Header a;
        ifstream ifs("testfile.dat", ios::binary);                //open file
        ifs.read((char *)&a, sizeof(Header));                        //read varibles
        cout << "File information\n";                                        //out put data to console.
        cout << "Signature: " << a.signature << endl;
        cout << "FileVersion: " << a.version << endl;
        cout << "Entries count: " << a.entries << endl;
        return 0;
}

---

but when i look at the output its not right. what I'm i doing wrong? i attach a picture of the console output.

Can you verify that sizeof(header) is twelve?

--
Mats

Quote:

---

Originally Posted by matsp

Can you verify that sizeof(header) is twelve?

--
Mats

---

Code:

---

#include <fstream>
#include <iostream>
using namespace std;

class Header                               
{
public:
        char  signature[4];                        //is logi
        unsigned int  version;                //greater than 5
        unsigned int  entries;                //number of entries
};

int main()
{
        Header a;
        ifstream ifs("testfile.dat", ios::binary);                //open file
        ifs.read((char *)&a, sizeof(Header));                        //read variables
        cout << "File information\n";                                        //out put data to console.
        cout << "Signature: " << a.signature << endl;
        cout << "FileVersion: " << a.version << endl;
        cout << "Entries count: " << a.entries << endl;
        cout <<        "Size of Header: " <<  sizeof(Header) << endl;
        return 0;
}

---

yes Header is 12;

Have you checked that read actually succeeds, because the value you are printing is 0xCCCCCCCC, which is MS VS standard fill pattern for "uninitialized stack space", so it appears that read isn't doing what you expect it to do. Are you sure the file is opening correctly?

--
Mats

Quote:

---

Originally Posted by matsp

Have you checked that read actually succeeds, because the value you are printing is 0xCCCCCCCC, which is MS VS standard fill pattern for "uninitialized stack space", so it appears that read isn't doing what you expect it to do. Are you sure the file is opening correctly?

--
Mats

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lol Mats you where right it wasn't opening the file. i had the hex editor open forgot to close it.

anyways this is what i have now for the output. how do i get rid of the char circle in red. and how would i go about reading the "namelenth" of the file since it is only 1 byte.

You are reading a 4 byte signature and printing it as a null-terminated string - there is no guarantee that there will be a zero to terminate the string...

--
Mats

You would be better served to read the file into a structure that matched the file layout, but then before printing it out, (or using other functions on the data), to copy it into a "well behaved" structure similar to what you have, but making an allowance for the null terminator as well.

>> Have you checked that read actually succeeds, because the value you are printing is 0xCCCCCCCC, which is MS VS standard fill pattern for "uninitialized stack space", so it appears that read isn't doing what you expect it to do.

Nice detective work there, matsp. :)

Quote:

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Originally Posted by Dino

You would be better served to read the file into a structure that matched the file layout, but then before printing it out, (or using other functions on the data), to copy it into a "well behaved" structure similar to what you have, but making an allowance for the null terminator as well.

---

first i like to say thank you to everyone who has tried to help me.

now I'm stuck.(doesn't surprise you. i know that's why I'm here :) )
The problem I am having now is how do i get the "namelength" from the file since it is only 1 byte and how do i add a variable name that is dependent on the namelenth
To the structure of a class call entries. also how would I get the hex value of the name.

Code:

---

Variable        entries
-----------------------------------------------------
1                      namelenth        uint8              Length of name
namelenth              name              char[]              name (nameLength characters) no terminating null
6                      id                uint8[6]            HEXVALUE 
8                FILETIME    FILETIME      100-nanosecond increments since January 1, 1601 (UTC). 64-bit integer
------------------------------------------------------------------------


class Entries                               
{
public:
        unsigned int8 namelenth;        //get the length of the name on 1 byte
        char name[namelenth];        // get the name      variable number of bytes
       
       
};

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So read takes, as the second argument, the sizeof the thing you're reading. So, put it there. (In the first case, you can use sizeof(yourvariable); in the second case, you can use the value of nameLength as the size to read.)

Quote:

---

Originally Posted by tabstop

So read takes, as the second argument, the sizeof the thing you're reading. So, put it there. (In the first case, you can use sizeof(yourvariable); in the second case, you can use the value of nameLength as the size to read.)

---

hi tabstop.
i know about the part on adding the lenth here is the code and the result the part i dont understand is how to get the namelenth which is 1byte.

Code:

---

#include <fstream>
#include <iostream>
using namespace std;

class Header                               
{
public:
        char  signature[4];                        //is logi
        unsigned int  version;                //greater than 5
        unsigned int  entries;                //number of entries
};
int main()
{
        Header a;
        ifstream ifs("testfile.dat", ios::binary);                //open file
        ifs.read((char *)&a, sizeof(Header));                        //read variables
        cout << "File information\n";                                        //out put data to console.
        cout << "Signature: " << a.signature << endl;
        cout << "FileVersion: " << a.version << endl;
        cout << "Entries count: " << a.entries << endl;
        cout <<        "Size of Header: " <<  sizeof(Header) << endl; //get the number of entries from the file.
        unsigned int  lenth; //how do you make this 1 byte int8
                ifs.read((char *)&lenth,1);
                cout << "Lenth of name: "  << lenth; //read lenth of name should be 13.
        return 0;
}

---

signature need to be of size 5 to hold the required terminating null character, which you will need to add yourself; i.e.,

Code:

---

signature[strlen("logi")] = '\0';

---

unsigned char namelength;

again i like to thank everyone for there help with this.


I'm wondering how do i get the HEXVALUE to display in Hexadecimal format.

Code:

---



#include <fstream>
#include <iostream>
using namespace std;

int main()
{
        char  signature[5];                        //is logi
        unsigned int  version;                //greater than 5
        unsigned int  entries;                //number of entries

        ifstream ifs("testfile.dat", ios::binary);                //OPEN FILE
               
        ifs.read((char *)&signature,4);                                        //Get Signature
        signature[4] = '\0';
       
        ifs.read((char *)&version, 4);                                        //Get Version
       
        ifs.read((char *)&entries, 4);                                        //Get Num Entries

        unsigned char  lenth;                                                        //Get Namelenth
        unsigned int nlenth;
        ifs.read((char *)&lenth,1);
        nlenth = (int)lenth;

        unsigned char *name;                                                        //Get NAME
        name = new unsigned char [nlenth+1];
        ifs.read((char *)&*name,nlenth);
        name[nlenth]='\0';
       

        unsigned char hexinput[6];                                                //Get HEXVALUE
        ifs.read((char *)&hexinput,6);

        //output data to console.
        cout << "File information\n";               
        cout << "Signature: " << signature << endl;
        cout << "FileVersion: " << version << endl;
        cout << "Entries count: " << entries << endl;
        cout << "Lenth of name: "  << nlenth << endl;
        cout << "The Name:  " << name <<endl;
        cout << "The hexvalue is: " << hexinput << endl;  //How do i make this look like the Hexadecimal value ;
        return 0;
}

---

1) You have to operate on a character at a time
2) The *prinft and *scanf functions have a formatter of "%x" that will aid you in your mission.

alright i got it to print in hex but how do i make it set this value to a string.
also how do i get the 64bit interger of FILETIME and show the date and time it is representing.

Code:

---

#include <fstream>
#include <iostream>
using namespace std;
/*
class Header                               
{
public:
        char  signature[5];                        //is logi
        unsigned int  version;                //greater than 5
        unsigned int  entries;                //number of entries
};*/
int main()
{
        char  signature[5];                        //is logi
        unsigned int  version;                //greater than 5
        unsigned int  entries;                //number of entries

        ifstream ifs("testfile.dat", ios::binary);                //OPEN FILE
               
        ifs.read((char *)&signature,4);                                        //Get Signature
        signature[4] = '\0';
       
        ifs.read((char *)&version, 4);                                        //Get Version
       
        ifs.read((char *)&entries, 4);                                        //Get Num Entries

        unsigned char  lenth;                                                        //Get Namelenth
        unsigned int nlenth;
        ifs.read((char *)&lenth,1);
        nlenth = (int)lenth;

        unsigned char *name;                                                        //Get NAME
        name = new unsigned char [nlenth+1];
        ifs.read((char *)&*name,nlenth);
        name[nlenth]='\0';
       
       
                                                                                                        //OUTPUT data to CONSOLE.
        cout << "File information\n";               
        cout << "Signature: " << signature << endl;
        cout << "FileVersion: " << version << endl;
        cout << "Entries count: " << entries << endl;
        cout << "Lenth of name: "  << nlenth << endl;
        cout << "The Name:  " << name <<endl;
        cout <<  "The hexvalue is: " ;
       

        unsigned char hexinput;                                                        //Get HEXVALUE
        unsigned int hexoutput;
        for (int i=1;i<6;i++)
        {
        ifs.read((char *)&hexinput,1);
        hexoutput = (int)hexinput;
        cout.setf(ios_base::hex, ios_base::basefield);
        if (hexoutput < 17) { cout << 0;}
        cout << std::hex << hexoutput ;                                        //How do i make this look like the Hexdicimal value in a string ;
        }
        cout << endl;

/*        unsigned long long filetime;  // DOESNT WORK;
        ifs.read((char *)&filetime,8);
        cout << "The date:  " << filetime;
*/

        return 0;
}

---

Instead of sending it to cout, you can send it to a StringStream. A very handy class.

Quote:

---

Originally Posted by Dino

Instead of sending it to cout, you can send it to a StringStream. A very handy class.

---

hi dino thank you for the replay Stringstream works very well.

now the only part I'm having problems with right now is the. FILETIME i need to know what is the right way to get this 64bit int out of the file and how i can convert this to unixtime so PHP can read it.








-----------------------------------------------------------------------------------------------------------
just something off subject here. last night i made the program. read all the logi entries i had in one directory right around 30,000,000 of them so I left the computer on to see how long it would take. and when i woke up in the morning i had an out of memory error. i thought well what can this program be doing that takes so much memory it shouldn't take more than about 2 megabytes. so i look at the code and didn't see any problems. i look at it again an there it was the for loop

Code:

---

for(int f=1;f<files;f++){
for (int i=1;i<=entries;i++){
}

---

declaring the variable in the loop was taking all my memory

so i added it to the head of the code and now the program takes only about 839k of memory.i know this might be old for some of you but who know maybe someone is here reading this right now that doesn't know where to look for a memory problem.

Code:

---

int i;
int f;
for(f=1;f<files;f++){
for(i=1;i<entries;i++){}}

---

anyways i need to get back to figuring out how to get the FILETIME from the file and read it. thank you all for your help on this program.

As to the FILETIME thing, do you know how the timestamp is output? (We've gone around and around and around with people who have a "perfectly standard timestamp" that no one knows how to interpret.) More importantly, that might give you some idea of how to read it in.

Anyway, g++ might take long long, or int64_t if you include inttypes.h. (I don't believe C++ has a standard way of getting at "types of a specific size, provided they exist" like C does.)

FILETIME is the number of 100-nanosecond since January 1, of 1601.... or something like that... I would not recommend using FILETIME if you are wanting to make your program work on OSes that are not Windows.

For the sake of tabstop's personal gratification (though I know him well enough to know he probably doesn't care terribly much). This example I wrote sort of unravels the mystery for you. :)

(Oh and for anyone who gives a damn: 11644473600 is the number of milliseconds between Jan 1, 1601 and Jan 1, 1970. And that other magic number is the coversion rate between 100-nanosecond or whatever to milliseconds)

nano you ninny. (I think)

Quote:

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Originally Posted by the beginning of the thread

8 FILETIME FILETIME 100-nanosecond increments since January 1, 1601 (UTC). 64-bit integer

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Yeah, ok. So you do know what that is, never mind. So it just comes down to getting that 64-bit variable (or, if push comes to shove, int filetime[2] and pretend its a 64-bit variable with some extra special math).

Quote:

---

Originally Posted by Dino

nano you ninny. (I think)

---

We will have to call it a push... its 100-nanosecond intervals... So technically we are both off by two powers of 10. Well played old bean. We shall meet again.

Quote:

---

Originally Posted by tabstop

Yeah, ok. So you do know what that is, never mind. So it just comes down to getting that 64-bit variable (or, if push comes to shove, int filetime[2] and pretend its a 64-bit variable with some extra special math).

---

One need not assume I read the beginnings of threads. Because I have never conveyed any gestures that could ever mislead someone to that conclusion.

@master: sorry I meant the OP. But you, too, can use an array of two ints to solve the problem of finding a 64-bit variable!

No biggy. I used the M$ structures to serve the same function as an array of two ints. For no other reason than to guarantee correct alignment.