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copied!<p>Very easy:</p> <ol> <li>Create target or destination file (a.k.a. open).</li> <li>Open source file in <code>binary</code> mode, which prevents OS from translating the content.</li> <li>Read an octet (byte) from source file; <code>unsigned char</code> is a good variable type for this.</li> <li>Write the octet to the destination using your favorite conversion, hex, decimal, etc.</li> <li>Repeat at 3 until the read fails.</li> <li>Close all files.</li> </ol> <p>Research these keywords: <code>ifstream, ofstream, hex modifier, dec modifier, istream::read, ostream::write</code>. </p> <p>There are utilities and applications that already perform this operation. On the *nix and Cygwin side try <code>od</code>, *octal dump` and pipe the contents to a file.</p> <p>There is the <code>debug</code> utility on MS-DOS system. </p> <p>A popular format is: </p> <pre><code>AAAAAA bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb cccccccccccccccc where: AAAAAA -- Offset from beginning of file in hexadecimal or decimal. bb -- Hex value of byte using ASCII text. c -- Character representation of byte, '.' if the value is not printable. </code></pre> <p>Please edit your post to provide more details, including an example layout for the target file.</p> <h2>Edit:</h2> <p>A complex example (not tested): </p> <pre><code>#include <iostream> #include <fstream> #include <cstdio> #include <cstdlib> using namespace std; const unsigned int READ_BUFFER_SIZE = 1024 * 1024; const unsigned int WRITE_BUFFER_SIZE = 2 * READ_BUFFER_SIZE; unsigned char read_buffer[READ_BUFFER_SIZE]; unsigned char write_buffer[WRITE_BUFFER_SIZE]; int main(void) { int program_status = EXIT_FAILURE; static const char hex_chars[] = "0123456789ABCDEF"; do { ifstream srce_file("binary.dat", ios::binary); if (!srce_file) { cerr << "Error opening input file." << endl; break; } ofstream dest_file("binary.txt"); if (!dest_file) { cerr << "Error creating output file." << endl; } // While no read errors from reading a block of source data: while (srce_file.read(&read_buffer[0], READ_BUFFER_SIZE)) { // Get the number of bytes actually read. const unsigned int bytes_read = srce_file.gcount(); // Define the index and byte variables outside // of the loop to maybe save some execution time. unsigned int i = 0; unsigned char byte = 0; // For each byte that was read: for (i = 0; i < bytes_read; ++i) { // Get source, binary value. byte = read_buffer[i]; // Convert the Most Significant nibble to an // ASCII character using a lookup table. // Write the character into the output buffer. write_buffer[i * 2 + 0] = hex_chars[(byte >> 8)]; // Convert the Least Significant nibble to an // ASCII character and put into output buffer. write_buffer[i * 2 + 1] = hex_chars[byte & 0x0f]; } // Write the output buffer to the output, text, file. dest_file.write(&write_buffer[0], 2 * bytes_read); // Flush the contents of the stream buffer as a precaution. dest_file.flush(); } dest_file.flush(); dest_file.close(); srce_file.close(); program_status = EXIT_SUCCESS; } while (false); return program_status; } </code></pre> <p>The above program reads 1MB chunks from the binary file, converts to ASCII hex into an output buffer, then writes the chunk to the text file.</p>

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