if (!file.fail()) { // 文件存在 } else { // 文件不存在 } 根据判断结果输出相应的信息: 根据文件是否存在,输出相应的信息。 cpp if (!file.fail()) { std::cout << "File exists." << std::endl; } else { std::cout << "File does not exist." <<...
std::ifstream file(filename); returnfile.is_open(); } intmain(){ std::string filename="/tmp/test"; if(isFileOpen(filename)){ std::cout<<"File is open."<<std::endl; // 在这里进行相关操作 return0; } std::cout<<"File is not open or does not exist."<<std::endl; return0;...
string FILENAME ="testfile.txt";\nint main(){\n FileStreamT file(FILENAME, std::ifstream::in | std::ios::binary);\n if(!file.is_open())\n std::cout<< "COULD NOT OPEN FILE" << std::endl;\n else{\n FileStreamT::char_type buff;\n file.read(&buff,1);\n std::cout <<...
ifstream:如何判断指定的文件是否不存在 我想打开一个文件进行阅读。但是,在这个程序的上下文中,如果文件不存在就可以了,我继续。我希望能够识别错误何时“未找到文件”以及何时出现错误。否则意味着我需要退出并出错。 我没有看到用 fstream 做这个的明显方法。 我可以用C的 open() 和 perror() 来做到这一点。我认...
编辑：我已经被告知，这并不一定表明一个文件不存在，因为它可能是由于访问权限或其他问题标记以及。我...
ios::nocreateIf the file does not already exist, the function fails. ios::binaryOpens the file in binary mode (the default is text mode). Note that theios::nocreateflag is necessary if you intend to test for the file's existence (the usual case). ...
ios::inThe file is opened for input (default). ios::nocreateIf the file does not already exist, the function fails. ios::binaryOpens the file in binary mode (the default is text mode). Note that theios::nocreateflag is necessary if you intend to test for the file’s existence (the ...
Everything compiles fine but nothing will create the file if file.is_open does not exist. i added the file << "//config file created"; for troubleshooting thinking maybe because i wasn't writing to the file that maybe that caused it not to create one. Still to no avail though. If ...
Why does ifstream throw an exception when EOF occurs? How to check if a file is open in a stream? Ifstream won't open file Solution 1: The reason for this is that "blah.txt" is being opened twice. First time: ifstream input_file("blah.txt", ios::in) ...
intopenInput(ifstream& opIn,stringunsortfile){ opIn.open(unsortfile.c_str());if(opIn.fail()){cout<<unsortfile<<" does not exist.\n"; opIn.close();return0; }elsereturn1; } 开发者ID:Yen168,项目名称:algorithms-computers-and-programming-cpp,代码行数:15,代码来源:P8_1.cpp ...