If stat returns 0, the file (or directory) exists, otherwise it doesn't. I assume that you'll have to have access permissions on all directories in the file's path. I haven't tested portability, but this page suggests it shouldn't be an issue. Share Improve this answer Follow answer...
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 log; log.exceptions( std::ifstream::failbit );try{ log.open("test.txt"); }catch(std::ifstream::failure e) { std::cout <<"Exception opening/reading file\n"; } Source I've tested, andifstreamwill throw afailureexception if the file cannot be opened, e.g. file not fo...
最近博客需要这么个功能，最初是想用file_exists()来判断本地文件的，奈何地址那里我填的是“http://...
是的,使用std::ifstream file(filename);语句会打开文件并创建一个文件输入流对象。如果文件不存在或者没有访问权限,它可能无法成功打开。你可以通过检查file.is_open()来确定是否成功打开了文件。如果返回值为true,则表示文件已经成功打开;如果返回值为false,则表示文件未能成功打开。
每个IO 对象都维护一组条件状态 flags (eofbit, failbit and badbit)，用来指出此对象上是否可以进行 IO...
ifstream myFile("filename.txt"); if(myFile.fail()){ //File does not exist code here } //otherwise, file exists Solution 2: It is difficult to determine if the file does not exist. A possible solution is to utilize is_open () for a more general check. ...
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::nocreate If the file does not already exist, the function fails. ios::binary Opens the file in binary mode (the default is text mode). Note that the ios::nocreate flag is necessary if you intend to test for the file’s existence (the usual case).nProtThe...
在构造函数体内部，我们直接可以用类的成员变量来赋值，但是在调用构造函数前是没有这个类对象的，既然都...