ifstream

问题 The code below will print all of the text from the sample text file I'm using except for the last little snippet of it. I think this has something to do with the eof or the byte size I'm using not working as I expect. #include <iostream> #include <fstream> using namespace std; int main(int argc, char* argv[]){ int length; char* buffer; //get file stream and open local file. ifstream stream; stream.open("SampleFile.txt", ios::binary); stream.seekg(0, ios::end); length = stream.tellg(); stream

问题 Why does this code print the char, without first character?? It says ocalhost instead of localhost . Grateful for help. #include <winsock2.h> #include <mysql/mysql.h> #include <iostream> #include <windows.h> #include <fstream> using namespace std; int main () { int b = 0; char * pch; int stringLength = 0; char textRead[50]; ifstream infile("config.ini", ios::in | ios::binary); if(!infile) { cout << "ERROR: config.ini not found!\n"; system("pause"); exit(0); } infile >> textRead; stringLength

问题 In VS 2005, I have some code that looks like this: ifs.open("foo"); while (!ifs.eof()) { ifs.read(&bar,sizeof(bar)); loc = ifs.tellg(); loc += bar.dwHeaderSize; // four byte boundary padding if ((loc % 4) != 0) loc += 4 - (loc % 4); ifs.seekg(loc,ios::beg); } ifs.close(); The code worked fine in VS 2005, but it fails in VS 2008 Express. From what I can tell, VS 2008 is not returning eof() after the code seeks to the end of the file. Am I missing something? I fixed it by adding an explicit

问题 I have an assignment where I am supposed to read multiple files containing integers (one on each line) and merge them into a output text file after sorting them. I am new to C++ so I do not know how everything works. I am testing my program with two .txt files. The first file is called fileone.txt, contains 1,2,7 (I do not know how to format this but they are all on different lines.) The second file is called filetwo.txt, and contains 1,3,5,9,10 (again every integer is on a different line). I

问题 I have an assignment where I am supposed to read multiple files containing integers (one on each line) and merge them into a output text file after sorting them. I am new to C++ so I do not know how everything works. I am testing my program with two .txt files. The first file is called fileone.txt, contains 1,2,7 (I do not know how to format this but they are all on different lines.) The second file is called filetwo.txt, and contains 1,3,5,9,10 (again every integer is on a different line). I

问题 I have a textfile that contains authors and the books written by authors. I am assigned to write a program in that the user will provide the name of a author. And the program must print the name of any books written by that author. I understand that i am supposed to use an ifstream to read this information. But how can i make it so my program doesn't read the entire file into memory (array, vector, etc.) to perform any of the search queries? What would be the best way to approach this? my

问题 I am trying to read data from a file using below code. (Note that you need to enable C++11 features on GCC to make this compile.) #include <fstream> typedef unsigned char byte; int main() { std::string filename = "test.cpp"; std::basic_ifstream<byte> in(filename, std::basic_ifstream<byte>::in | std::basic_ifstream<byte>::binary); in.exceptions(std::ios::failbit | std::ios::badbit); byte buf[5]; in.read(buf, 5); return 0; } However, when reading data I get an exception: terminate called after

问题 I don't understand what is throwing the exception here with my input file stream. I have done almost the exact thing before without any problems. std::string accnts_input_file = "absolute_path/account_storage.txt"; std::string strLine; std::ifstream istream; istream.exceptions( std::ifstream::failbit | std::ifstream::badbit ); try { istream.open( accnts_input_file.c_str() ); while( std::getline( istream, strLine ) ) { std::cout << strLine << '\n'; } istream.close(); } catch( std::ifstream:

问题 In the project I'm working on, I deal with quite a few string manipulations; strings are read from binary files along with their encoding (which can be single or double byte). Essentially, I read the string value as vector<char> , read the encoding and then convert all strings to wstring , for consistency. This works reasonably well, however the filenames themselves can be double-byte chars. I'm totally stumped on how to actually open the input stream. In C I would use _wfopen function

问题 I'm trying to read in a file that contains matrix data into a boost matrix. "" is already supposed to have operator overloads for this sort of thing and I can get it to write to a standard stream (cout). I don't know what's wrong with going the other way. I'm fairly new to C++, so I'm guessing I'm making an incorrect assumption regarding file streams, but it seemed like it made sense. Here are the web pages I'm going on: http://www.boost.org/doc/libs/1_51_0/boost/numeric/ublas/io.hpp http:/