Normally, puts does not write immediately to STDOUT, but buffers the strings internally and writes the output in bigger chunks. This is done because IO operations are slow, and usually it makes more sense to avoid writing every single character immediately to the console. This behavior leads to problems in certain situations. Imagine you want … Read more
I think you have a fundamental misunderstanding about IO in Haskell. Particularly, you say this: Maybe there is a function which can convert from ‘IO String’ to [Char]? No, there isn’t1, and the fact that there is no such function is one of the most important things about Haskell. Haskell is a very principled language. … Read more
shutil.copyfile and shutil.copyfileobj for the rescue. See http://docs.python.org/library/shutil.html#module-shutil
It’s interesting that though the question might seem reasonable, it’s not that easy to figure out a practical reason why I would need to convert a StringIO into a BytesIO. Both are basically buffers and you usually need only one of them to make some additional manipulations either with the bytes or with the text. … Read more
The accepted answer is correct, but as of bash 4.1, you can use automatic file descriptor allocation, and in that case you don’t need eval: file=a exec {id}<>”$file” Then you can use it like this: echo test >&${id} or: fsck -v -f -C ${id} /dev/something
There seems to be no perfect way. The root of the problem is that clock_t can be either integer or floating point. clock_t can be a floating point type As Bastien Léonard mentions for POSIX (go upvote him), C99 N1256 draft 7.23.1/3 also says that: [clock_t is] arithmetic types capable of representing times and 6.2.5/18: … Read more
I would use a specialized writer if I wanted to make a String out of it. Writer writer = new StringWriter(); String data = writer.toString(); // now it works fine
It’s possible that you are calling a method like nextInt() before. Thus a program like this: Scanner scanner = new Scanner(System.in); int pos = scanner.nextInt(); System.out.print(“X: “); String x = scanner.nextLine(); System.out.print(“Y: “); String y = scanner.nextLine(); demonstatres the behavior you’re seeing. The problem is that nextInt() does not consume the ‘\n’, so the next … Read more
Most people use powers of 2 for the size. If the buffer is at least 512 bytes, it doesn’t make much difference ( < 20% ) For network the optimal size can be 2 KB to 8 KB (The underlying packet size is typically up to ~1.5 KB) For disk access, the fastest size can … Read more
What alternatives are there to monads for I/O in a pure functional language? I’m aware of two alternatives in the literature: One is a so-called linear type system. The idea is that a value of linear type must be used exactly one time: you can’t ignore it, and you can’t use it twice. With this … Read more