1voidopen (constchar* filename, ios_base::openmode mode = ios_base::in);2voidopen (conststring& filename, ios_base::openmode mode = ios_base::in); 函数参数: filename要打开文件的文件名 mode打开文件的方式 3.ifstream:: is_open 1boolis_open()const; 文件流对象与文件绑定,返回 true ,...
检查代码是否有异常处理来捕获打开文件时的错误: 虽然std::ifstream的构造函数在打开文件失败时不会抛出异常,但可以通过检查is_open()的返回值来处理错误。cpp try { std::ifstream file("nonexistent/file/path.txt"); if (!file.is_open()) { throw std::runtime_error("Failed to open file"); } /...
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。 以下是修改后的示例代码: #include<iostream> #include<fstream> boolisFileOpen(conststd::string&filename){ std::ifstream file(filename); returnfile.is_open();...
#include <string> #include <fstream> #include <iostream> // 此文件名为 main.cpp bool file_exists(const std::string& str) { std::ifstream fs(str); return fs.is_open(); } int main() { std::boolalpha(std::cout); std::cout << file_exists("main.cpp") << '\n' << file_exist...
bool is_open() const; 检查文件流是否有关联文件。 相当于调用 rdbuf()->is_open()。 参数(无) 返回值文件流有关联文件时返回 true,否则返回 false。 示例运行此代码 #include <fstream> #include <iostream> #include <string> // 此文件名为 main.cpp bool file_exists(const std::string& str) {...
std::basic_ifstream<CharT,Traits>::is_open From cppreference.com <cpp |io |basic ifstream C++ Checks if the file stream has an associated file. Effectively callsrdbuf()->is_open(). Parameters (none) Return value trueif the file stream has an associated file,falseotherwise. ...
basic_ifstream::is_open basic_ifstream::open basic_ifstream::close Non-member functions swap(std::basic_ifstream) (C++11) basic_ifstream(); (1) explicitbasic_ifstream(constchar*filename, std::ios_base::openmodemode =std::ios_base::in); ...
empty()) is.setstate(std::ios::eofbit); return is; default: t += (char)c; } } } 这是一个测试程序: int main() { std::string path = ... // insert path to test file here std::ifstream ifs(path.c_str()); if(!ifs) { std::cout << "Failed to open the file." << ...
if (!is_buffer_valid_nolock(stream, Character())) { stream.set_flags(stream->_cnt != 0 ? _IOERROR : _IOEOF); stream->_cnt = 0; return stdio_traits::eof; } Here, on the CRT level, _IOERROR flag is correctly set, but unfortunately it seems that this information is ...
iostate exceptionMask = comport.exceptions() | std::ios::failbit; comport.exceptions(exceptionMask); try { comport.open("COM6:", std::ifstream::in); } catch (std::ios_base::failure &e) { std::string erroropen( e.what() ); } while (comport.is_open() ) { std::getline(com...