table of contents
std::basic_ifstream::is_open(3) | C++ Standard Libary | std::basic_ifstream::is_open(3) |
NAME¶
std::basic_ifstream::is_open - std::basic_ifstream::is_open
Synopsis¶
bool is_open(); (until C++11)
bool is_open() const; (since C++11)
Checks if the file stream has an associated file.
Effectively calls rdbuf()->is_open().
Parameters¶
(none)
Return value¶
true if the file stream has an associated file, false otherwise
Example¶
// Run this code
#include <string>
#include <fstream>
#include <iostream>
//this file is called 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_exists("strange_file") << '\n';
}
Possible output:¶
true
false
See also¶
open opens a file and associates it with the stream
(public member function)
close closes the associated file
(public member function)
2022.07.31 | http://cppreference.com |