Write hex in text file to other file

[fabtasticwill]

I need some help getting hex from a text file and writing it to a different file.
I made a program to dump hex from files into a text file and now I need it to save the hex to the original file. Here is my code to save the hex:

int main(int argc, char * argv[]) {
	ofstream myFile;
	ifstream file(argv[1], ios::in);
	myFile.open(argv[2], ios::out | ios::binary);
	char buffer[BUFFER_SIZE];
	char temp;
	int len = sizeof(buffer);
        if(file.is_open())
        {

		for(int i = 0;!file.eof(); ++i)
                {
			buffer[i] = '0x';
                        file >> temp;
			buffer[i] += temp;
			temp = NULL;
			
		}
        }
	file.close();
	cout<<buffer;
	myFile.write(buffer, BUFFER_SIZE);
	
	myFile.close();
	return 0;

}

It never outputs the correct contents of the file that has been dumped. I've checked with other hex editors and the hex dumper is working correctly.

[SIK]

can you please post a snippet of data of the input hex text file.

[fabtasticwill]

These are the first few lines:

 58 45 58 32 00 00 00 01 00 00 10 00 00 00 00 00
 00 00 00 70 00 00 00 0B 00 00 03 FF 00 00 02 3C
 00 01 01 00 92 00 23 38 00 01 02 01 92 00 00 00
 00 01 03 FF 00 00 0E 14 00 01 80 02 00 00 02 60
 00 01 83 FF 00 00 02 68 00 02 00 FF 00 00 02 78
 00 02 01 04 00 00 02 DC 00 02 02 00 00 01 00 00
 00 04 00 06 00 00 02 EC 00 04 04 04 00 00 03 04
 00 00 01 CC 00 00 80 00 F4 81 32 C1 21 81 B4 4F
 4D 82 78 2A 74 1B E8 2D B3 A5 D3 D6 30 4C A8 69
 3B C1 20 D9 B7 65 DA C6 02 C8 80 BD 35 F9 A2 0B
 29 A3 C7 51 77 7F DB 68 96 DE 84 0C DF 2E 26 A0
 83 1F E4 8B 1D 72 6A 79 6F 74 EC 5B 31 A5 62 BC
 51 A9 37 62 51 1E 56 0B 98 F0 3C 4C A3 17 42 1F

[SIK]

given the structure of your input file, you should be reading each 2 digit string from the input file and converting string value read to corresponding byte value. you can accomplish this with:

int HexByteStringToInt(const string & strHB)
{
   return (strHB[0]-'0')*16 + strHB[1]-'0';
}

does this help?

[whitenite1]

@fabtasticwill

I'm not sure how to correct it, but the main problem you're having is that each character is being read separately into buffer[i]. IE: First number, 58, is being read as 5 then the next buffer[i] reads the 8, since char only holds one character.

[fabtasticwill]

Thanks, but how exactly would I use this? I tried using that on the buffer, but that didn't help.

[fabtasticwill]

Thanks for the reply. I tried using char * instead of char but it said temp was uninitialized, even though it was being read from a file.

[SIK]

within your file reader section, try reading each word into a string, ie, from your input snippet the first word read into say string strHexByte would be "58"

the next would be "45", ...

each time you read a hex byte you should pass it to function HexByteStringToInt.

this will convert the hexadecimal byte value stored in [strHexByte] to the corresponding integer value.

for example: HexByteStringToInt("58") = 88.

you then place 88 inside of your buffer and advance the index.

once done you should be able to write the buffer to file and end up with a copy of the original binary.

[fabtasticwill]

I just tried that but when I run it, it says the program stopped working and closed. I'll give you the code i'm trying.

int HexByteStringToInt(const string & strHB)
{
   return (strHB[0]-'0')*16 + strHB[1]-'0';
}

int main(int argc, char * argv[]) {
	ofstream myFile;
	ifstream file(argv[1], ios::in);
	myFile.open(argv[2], ios::out | ios::binary);
	char * buffer[BUFFER_SIZE];//When I did it with char it worked correctly with this. = {0x58, 0x45, 0x5, 0x32, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00};
	char * temp = "  ";
	int len = sizeof(buffer);
        if(file.is_open())
        {

		for(int i = 0;!file.eof(); ++i)
               {
                        file >> buffer[i];
			buffer[i] = (char *)HexByteStringToInt(buffer[i]);
		
			
		}

	
        }
	file.close();


	myFile.write((char *)buffer, BUFFER_SIZE);
	
	myFile.close();
	return 0;

}

[fabtasticwill]

Ok, I just got it working, but i've got one problem. The output file has spaces between all the characters. I need to get rid of that. heres my code:

int main(int argc, char * argv[]) {
	ofstream myFile;
	ifstream file(argv[1], ios::in);
	myFile.open(argv[2], ios::out | ios::binary);
	int buffer[BUFFER_SIZE];
        if(file.is_open())
        {
		for(int i = 0;i < BUFFER_SIZE; ++i)
                {
                     file >>hex>> buffer[i];			
		}
        }
	file.close();

	myFile.write((char *)buffer, BUFFER_SIZE);
	
	myFile.close();
	return 0;

}

[SIK]

don't read from file into buffer, instead try reading from file into a string such that you get a two character string each time before you pass value to the HexByteStringToInt function.

don't read one byte out of your input file at a time (unless you build in the logic to combine characters to form the require hex byte strings.

change line 18 from

file >> buffer[i];

to:

string strHB;
file >> strHB;

[fabtasticwill]

I'm not using HexByteStringToInt anymore. I got it working without it. My problem now is that it adds spaces between all characters in the output file.

[SIK]

you should then try my suggestion

[fabtasticwill]

You mean using a string instead of and int? I tried and it didn't work and i'm not sure why. Here's the code I tried:

int main(int argc, char * argv[]) {
	ofstream myFile;
	ifstream file(argv[1], ios::in);
	myFile.open(argv[2], ios::out | ios::binary);
	int buffer[BUFFER_SIZE];
	char * result;
        if(file.is_open())
        {
		for(int i = 0;!file.eof(); ++i)
                {
                        file>>hex>> result[i];
			cout << hex << result[i] << ' ';
		}
        }
	file.close();
	myFile.write(result, BUFFER_SIZE);
	
	myFile.close();
	return 0;

}

[SIK]

my suggestion was to use a stl string.

so line 6 should become:

string result;

also remove the [hex] keyword from your file read operation.

also ensure that you include the correct stl files:

#include <iostream>
#include <fstream>
#include <string>

notice the absence the the [.h] extension.

[fabtasticwill]

When I tried that, it outputed

ØîZ 2A ÌÌÌÌÌÌÌÌÌÌÌÌÌ      ÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌÌ

there are a lot more of the Ì than I put. I used cout to look at the string and it had the hex. I think the problem was converting it to char *.

[SIK]

the line:

myFile.write(result, BUFFER_SIZE);

should be

myFile.write(result, actual_byte_cnt);

where actual_byte_cnt is the actual number of bytes converted instead of the total size of your output buffer

[fabtasticwill]

Thanks, but I know that. I was just using BUFFER_SIZE as a temporary solution. Thats where all the Ì come from. Right now all I need is to remove the extra spaces.

[SIK]

don't define buffer as an array of type [int] instead define it as an array of type char, like:

char buffer[BUFFER_SIZE];

an int is usually defined as 4 bytes in length whereas a char is define as having length of 1 byte.

this might be where the extra spaces/junk in between is coming from.

[fabtasticwill]

Thanks, I'll try it and see if it works.