io

问题 I'm trying to read one line at a time, of arbitrary length, from stdin at the command line. I'm not sure if I'll be able to include GNU readline and would prefer to use a library function. The documentation I've read suggests that getline ought to work, but in my experiments it doesn't block. My sample program: #include <stdio.h> int main() { char *line = NULL; if (getline(&line, NULL, stdin) == -1) { printf("No line\n"); } else { printf("%s\n", line); } return 0; } produces No line , which

问题 I'm working on a project where I have to write a class that contains three other classes as private member variables to a binary file, where it can then be read back into variables to be used in the code. The code writes to the file, but I don't know if it is writing the correct info as when I try to read the file it reads in junk. I have included my current setup, does this look correct? If so, what could be going wrong, and if not, how can I fix this? If you need me to add any extra code,

问题 This question already has answers here : How to append text to an existing file in Java? (31 answers) Closed 3 years ago . I have one project that I want to get input from jframe. I have to input 3 people data in only one time when code was running and write that data into file name person.txt.Those data have Name Nickname Age and when i compile my code, It dosn't work and I just only write one data in person.txt file. Help me please? I can't get those in my project. what should i do ? public

问题 In the answer to this question I don't understand why the input.nextInt has a newline character as a leftover. Scanner is skipping nextLine() after using next(), nextInt() or other nextFoo()? 回答1: The answer is quite simple: Scanner#nextInt() reads the next integer but not the newline ( ENTER ) the user presses to submit the integer. To understand this you must know that everything you type will be written to a buffer, from which the Scanner methods try to read from. Regard the following

问题 In the answer to this question I don't understand why the input.nextInt has a newline character as a leftover. Scanner is skipping nextLine() after using next(), nextInt() or other nextFoo()? 回答1: The answer is quite simple: Scanner#nextInt() reads the next integer but not the newline ( ENTER ) the user presses to submit the integer. To understand this you must know that everything you type will be written to a buffer, from which the Scanner methods try to read from. Regard the following

问题 I know as a fact, that we cant implement an IO monad independently, but I dont know why exactly. This code is an attempt to implement an imperative paradigm using functional language. Can you explain the difference between this example and true IO? It looks like function main implements the correct action order and remains lazy. import System.IO.Unsafe data Io a = Io a runIO :: Io a -> a runIO (Io a) = a instance Monad Io where return x = Io x Io a >>= f = f a -- internal side effect function

问题 Consider this simple C++ program: #include <cstdint> #include <iostream> int main() { uint8_t var; std::cin >> var; std::cout << "var = " << var << '\n'; if (var == 1) { std::cout << "var is 1\n"; } else { std::cout << "var is not 1\n"; } } Running it shows some surprising behavior. When the input is 1 , the output is var = 1 var is not 1 which is clearly absurd! After quite a few varied tests, I realized what is happening—it's reading and writing a char! Still, it's not the behavior I want—I

问题 i have a simple problem. i use this code to add some records in text file using java but every time i run this program, the file is being created again. i wanna to append records without creating file again ? Formatter x = null; try{ x = new Formatter("C:\\Users\\Hamada\\Downloads\\products.txt"); } catch(Exception e) { //System.out.println("NO Database"); } x.format("%d,%s,%s,%s,%d,%d,%d,%d,%d,%d,%d",id, name, type, brand, quantity, day1, month1, year1, day2, month2, year2); x.close(); 回答1:

问题 I am constantly getting Expected BEGIN_TYPE but was STRING at line 1 column 1 path $ error. I've read about that error, but I am experiencing something different. When I try to use gson.fromJson() on a JSON string I've created in my app it compiles fine. ArrayList<MyCar> cars = new ArrayList<>(); cars.add(new MyCar()); cars.add(new MyCar()); String json = gson.toJson(cars); This compiles. Type carList = new TypeToken<ArrayList<MyCar>>(){}.getType(); ArrayList<MyCar> myCars = gson.fromJson

问题 I am trying to extract an application resource from My.Resources.FILE I have discovered how to do this with DLL & EXE files, but I still need help with the code for extracting PNG & ICO files. Other file types also. (If possible) Here is my current code that works with DLL & EXE files. Dim File01 As System.IO.FileStream = New System.IO.FileStream("C:\Users\" + Environment.UserName + "\Desktop\" + "SAMPLE.EXE", IO.FileMode.Create) File01.Write(My.Resources.SAMPLE, 0, My.Resources.SAMPLE.Length