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I am currently attempting to store a string containing binary code.

When I attempt to write this string to a text file it simply stores each 0 and 1 character in a string format, rather than storing it into 8 bit chunks as I require. This causes the file to be larger than intended, considering it uses 8 bits to store each 0 and 1.

Should I write the string to a .bin file instead of a .txt file? If so how would I go about doing this, and if possible an example with some working code.

My thanks for any advice in advance.

   string encoded = "01010101";    
   ofstream myfile;   
   myfile.open ("encoded");   
   myfile <<  encoded;   
   myfile.close();

Clarification: I have a string made up of 1's and 0's(resulting from a Huffman Tree), I wish to break this string up into 8 bit chunks, I wish to write each character represented by said chink to a compressed file.

user2202417
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  • Do you have a good reason for storing binary data in strings? Can't use something meant for storing binary data? – Pubby Mar 23 '13 at 14:22
  • I am attempting to store binary resulting from encoding text through the use of a Huffman tree. The issue I am having is writing the binary to a file in a 8 bit compressed manner. – user2202417 Mar 23 '13 at 15:00

3 Answers3

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I'm only guessing since you don't show any code, but it seems you have a string containing the characters '1' and '0'. If you write that to a file of course it will be as a text. You need to convert it to integers first.

See e.g. std::stoi or std::strtol for functions to convert strings of arbitrary base to integers.

Some programmer dude
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std::bitset can convert a string to an integer.

std::bitset<8> bits("01010101");
cout << bits.to_ullong();
Peter Wood
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Should I write the string to a .bin file instead of a .txt file?

If you wish so... But that wouldn't make a difference either. ofstream doesn't care about filenames. Just convert the string to a byte (uint8_t) and write that byte to the file:

string s = "10101010";
uint8_t byte = strtoul(s.c_str(), NULL, 2);
myfile << byte;
  • Like so? `string test = "01010101"; uint8_t byte = strtoul(test.c_str()); ofstream myfile3; myfile3.open ("binary.txt"); myfile3 << test; myfile3.close();` @H2CO3 – user2202417 Mar 23 '13 at 14:46
  • @user2202417 Yes, except that I accidentally left out two arguments of `strtoul`. See edit. –  Mar 23 '13 at 16:40