See this response by Jack Klein (see original post): The original C standard (ANSI 1989/ISO 1990) required that a compiler successfully translate at least one program containing at least one example of a set of environmental limits. One of those limits was being able to create an object of at least 32,767 bytes. This minimum … Read more
The program will not work properly because at Line 1, when the user presses Enter, it will leave in the input buffer 2 character: Enter key (ASCII code 13) and \n (ASCII code 10). Therefore, at Line 2, it will read the \n and will not wait for the user to enter a character. The … Read more
The POSIX answer is tcflush(): flush non-transmitted output data, non-read input data, or both. There is also tcdrain() which waits for output to be transmitted. They’ve been in POSIX since there was a POSIX standard (1988 for the trial-use version), though I don’t recall ever using them directly. Example program Compile this code so the … Read more
The basic idea of buffering is to combine operations into bigger chunks: instead of reading small number of bytes, read an entire page and make this available as requested; instead of writing small number of bytes, buffer them up and write an entire page or when writing is explicitly requested. Essentially, this is an important … Read more
You can increase the value from the default, but you can’t increase it beyond the maximum value. Use setsockopt to change the SO_RCVBUF option: int n = 1024 * 1024; if (setsockopt(socket, SOL_SOCKET, SO_RCVBUF, &n, sizeof(n)) == -1) { // deal with failure, or ignore if you can live with the default size } Note … Read more
You are probably looking for io.BytesIO class. It works exactly like StringIO except that it supports binary data: from io import BytesIO bio = BytesIO(b”some initial binary data: \x00\x01″) StringIO will throw TypeError: from io import StringIO sio = StringIO(b”some initial binary data: \x00\x01″)
Buffers are associated with a specific block device, and cover caching of filesystem metadata as well as tracking in-flight pages. The cache only contains parked file data. That is, the buffers remember what’s in directories, what file permissions are, and keep track of what memory is being written from or read to for a particular … Read more
The order of local variable on the stack is unspecified. It may change between different compilers, different versions or different optimization options. It may even depend on the names of the variables or other seemingly unrelated things.
On many architectures, comparing 1 byte takes the same amount of time as 4 or 8, or sometimes even 16. 4 bytes is normally easy (either int or long), and 8 is too (long or long long). 16 or higher probably requires inline assembly to e.g., use a vector unit. Also, a branch mis-predictions really … Read more
Yes, the code is legal in C++11 because the storage for std::string is guaranteed to be contiguous and your code avoids overwriting the terminating NULL character (or value initialized CharT). From N3337, ยง21.4.5 [string.access] const_reference operator[](size_type pos) const; reference operator[](size_type pos); 1 Requires: pos <= size(). 2 Returns: *(begin() + pos) if pos < size(). … Read more