getline

#include <iostream> #include <fstream> #include <string> using namespace std; //getline();用法 //将一个文件的内容按行复制到另一个文件 void copyFromFile() { ifstream in("copy.txt"); ofstream out("copy2.txt"); string s; while (getline(in, s))//getline 会去掉换行符 { out << s << "\n";//所以要加上换行符 } } //将文件内容复制到string对象中 void copyToString() { ifstream in("copy.txt"); string line; string result; while (getline(in, line))//getline 会去掉换行符 { result += line + "\n";//不用担心string的内存分配 但是文件最好抽象成多行的集合而不是一大段文本 } cout << result; } int main() { copyToString(); return 0; } 来源： https://www.cnblogs.com/tailiang/p/11972150.html

while(getline (&line, &line_size, f) != -1){} I'm using this function to read line line. But i want to know when i'm reading a blank line. Can someone help? none so as H2CO3 already mentioned you can use the line length for this: while (getline (&line, &line_size, f) != -1) { if (strlen(line) == 1) { printf("H2CO3 spotted a blank line\n"); } /* or alternatively */ if ('\n' == line[0]) { printf("Ed Heal also spotted the blank line\n"); } .. } You need to define blank line. Also, because "The getline function reads an entire line from a stream, up to and including the next newline character." I

I have gone through many posts on SO , but still i am not able to resolve the issue . I have to read : text pattern1 pattern2 from standard input , there are many text and patterns . Code : string t,p1,p2; while(getline(cin, t)) { cin>>p1; cin>>p2; cout<<"text is = "<<t<<"\np1 is = "<<p1<<"\np2 is = "<<p2<<endl; } Input file : hammer ham mer gogoa go z gogoa g o Output : text is = hammer p1 is = ham p2 is = mer text is = p1 is = gogoa p2 is = go text is = p1 is = z p2 is = gogoa text is = p1 is = g p2 is = o Marco A. If you're using getline after cin >> something , you need to flush the

Data saved in my file is (white spaces added at both beginning and end on purpose for this test): 1 2 3 Loading the data using the code below with or without "std::ws" does not cause any difference. So I am confused by the role of "std::ws" as I have seen code using it. Can someone explain a little bit? Thanks! void main () { ifstream inf; inf.open ("test.txt"); double x=0, y=0, z=0; string line; getline(inf, line); istringstream iss(line); //Using "std::ws" here does NOT cause any difference if (!(iss >> std::ws >> x >> y >> z >> std::ws)) { cout << "Format error in the line" << endl; } else

From what I've read, getline() used in a Boolean context returns an implicitly conversion to void* . I haven't found anywhere on the web any real reference to this statement. Everywhere it says that implicit conversion doesn't exist and that in a Boolean context pointers should be of the same kind (and if ptr == 0 than 0 is converted to type of the pointer ptr ). Also in the standard says in a Boolean context it is converted to an unspecified-Boolean-type. What does that even mean? Martin York In short: It means that you can use getline() in a if statement and if it works you enter the if

1022 Digital Library (30 分) A Digital Library contains millions of books, stored according to their titles, authors, key words of their abstracts, publishers, and published years. Each book is assigned an unique 7-digit number as its ID. Given any query from a reader, you are supposed to output the resulting books, sorted in increasing order of their ID's. Input Specification: Each input file contains one test case. For each case, the first line contains a positive integer N ( ≤) which is the total number of books. Then N blocks follow, each contains the information of a book in 6 lines: Line

I'm trying to read lines from .txt files, that have been saved as Unicode. That's how i'm doing it: wifstream input; string path = "test.txt"; input.imbue(locale(input.getloc(), new codecvt_utf16<wchar_t, 0x10ffff, consume_header>)); input.open(path); if (input.is_open()) { wstring line; input.seekg( 1 , ios_base::beg); getline(input, line); } It works fine for files with Latin characters. But for Cyrillic files I get weird symbols instead of spaces and adjacent characters. For example: What is in the input file: Госдеп США осудил нападение на What I get: ︓осдепР!ШАР>судилР=ападениеР=а What am