std::filesystem::directory_entry::exists
From cppreference.com
< cpp | filesystem | directory entry
| bool exists() const; |
(1) | (since C++17) |
| bool exists( std::error_code& ec ) const noexcept; |
(2) | (since C++17) |
Checks whether the pointed-to object exists. Effectively returns:
1) std::filesystem::exists(status()),
2) std::filesystem::exists(status(ec)).
Note that status() follows symlinks to their targets.
Parameters
| ec | - | out-parameter for error reporting in the non-throwing overload |
Return value
true if the referred-to filesystem object exists.
Exceptions
Any overload not marked noexcept may throw std::bad_alloc if memory allocation fails.
1) Throws std::filesystem::filesystem_error on underlying OS API errors, constructed with p as the first path argument and the OS error code as the error code argument.
2) Sets a std::error_code& parameter to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur.
Example
Run this code
#include <filesystem> #include <iostream> int main() { for (auto const str: { "/usr/bin/cat", "/usr/bin/mouse", "/usr/bin/python", "/usr/bin/bison", "/usr/bin/yacc", "/usr/bin/c++", }) { std::filesystem::directory_entry entry{str}; std::cout << "directory entry " << entry << (entry.exists() ? " exists\n" : " does not exist\n"); } }
Possible output:
// Output on a POSIX system: directory entry "/usr/bin/cat" exist directory entry "/usr/bin/mouse" does not exist directory entry "/usr/bin/python" exists directory entry "/usr/bin/bison" exists directory entry "/usr/bin/yacc" does not exist directory entry "/usr/bin/c++" exists
See also
| (C++17) |
checks whether path refers to existing file system object (function) |