The easiest way is probably to create an std::bitset representing the value, then stream that to cout. #include <bitset> … char a = -58; std::bitset<8> x(a); std::cout << x << ‘\n’; short c = -315; std::bitset<16> y(c); std::cout << y << ‘\n’;
xxd does both binary and hexadecimal. bin: xxd -b file hex: xxd file
For reference—future Python possibilities: Starting with Python 2.6 you can express binary literals using the prefix 0b or 0B: >>> 0b101111 47 You can also use the new bin function to get the binary representation of a number: >>> bin(173) ‘0b10101101′ Development version of the documentation: What’s New in Python 2.6
Decode it. >>> b’a string’.decode(‘ascii’) ‘a string’ To get bytes from string, encode it. >>> ‘a string’.encode(‘ascii’) b’a string’
Your first mistake is thinking that ASCII encoding and Base64 encoding are interchangeable. They are not. They are used for different purposes. When you encode text in ASCII, you start with a text string and convert it to a sequence of bytes. When you encode data in Base64, you start with a sequence of bytes … Read more
Python 2.4 and Earlier f = open(“myfile”, “rb”) try: byte = f.read(1) while byte != “”: # Do stuff with byte. byte = f.read(1) finally: f.close() Python 2.5-2.7 with open(“myfile”, “rb”) as f: byte = f.read(1) while byte != “”: # Do stuff with byte. byte = f.read(1) Note that the with statement is not … Read more
Two’s complement is a clever way of storing integers so that common math problems are very simple to implement. To understand, you have to think of the numbers in binary. It basically says, for zero, use all 0’s. for positive integers, start counting up, with a maximum of 2(number of bits – 1)-1. for negative … Read more
Python’s string format method can take a format spec. >>> “{0:b}”.format(37) ‘100101’ Format spec docs for Python 2 Format spec docs for Python 3
This is known as the ‘Hamming Weight’, ‘popcount’ or ‘sideways addition’. Some CPUs have a single built-in instruction to do it and others have parallel instructions which act on bit vectors. Instructions like x86’s popcnt (on CPUs where it’s supported) will almost certainly be fastest for a single integer. Some other architectures may have a … Read more
Python 3.x makes a clear distinction between the types: str = ‘…’ literals = a sequence of Unicode characters (Latin-1, UCS-2 or UCS-4, depending on the widest character in the string) bytes = b’…’ literals = a sequence of octets (integers between 0 and 255) If you’re familiar with: Java or C#, think of str … Read more