Extract hexdump or RAW data of a file to text - c++

Question

I was wondering if there is a way to output the hexdump or raw data of a file to txt file.
for example
I have a file let's say "data.jpg" (the file type is irrelevant) how can I export the HEXdump (14ed 5602 etc) to a file "output.txt"?
also how I can I specify the format of the output for example, Unicode or UTF?
in C++

Answer 1

You can use a loop, fread and fprintf: With read you get the byte-value of the bytes, then with fprintf you can use the %x to print hexadecimal to a file.
http://www.cplusplus.com/reference/clibrary/cstdio/fread/
http://www.cplusplus.com/reference/clibrary/cstdio/fprintf/
If you want this to be fast you load whole machine-words (int or long long) instead of single bytes, if you want this to be even faster you fread a whole array, then sprintf a whole array, then fprintf that array to the file.

Answer 2

Maybe something like this?
#include <sstream>
#include <iostream>
#include <iomanip>
#include <iterator>
#include <algorithm>
int main()
{
std::stringstream buffer( "testxzy" );
std::istreambuf_iterator<char> it( buffer.rdbuf( ) );
std::istreambuf_iterator<char> end; // eof
std::cout << std::hex << std::showbase;
std::copy(it, end, std::ostream_iterator<int>(std::cout));
std::cout << std::endl;
return 0;
}
You just have to replace buffer with an ifstream that reads the binary file, and write the output to a textfile using an ofstream instead of cout.

Answer 3

This is pretty old -- if you want Unicode, you'll have to add that yourself.
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) {
unsigned long offset = 0;
FILE *input;
int bytes, i, j;
unsigned char buffer[16];
char outbuffer[60];
if ( argc < 2 ) {
fprintf(stderr, "\nUsage: dump filename [filename...]");
return EXIT_FAILURE;
}
for (j=1;j<argc; ++j) {
if ( NULL ==(input=fopen(argv[j], "rb")))
continue;
printf("\n%s:\n", argv[j]);
while (0 < (bytes=fread(buffer, 1, 16, input))) {
sprintf(outbuffer, "%8.8lx: ", offset+=16);
for (i=0;i<bytes;i++) {
sprintf(outbuffer+10+3*i, "%2.2X ",buffer[i]);
if (!isprint(buffer[i]))
buffer[i] = '.';
}
printf("%-60s %*.*s\n", outbuffer, bytes, bytes, buffer);
}
fclose(input);
}
return 0;
}