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 )constnoexcept; | (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.
Contents |
[edit]Parameters
| ec | - | out-parameter for error reporting in the non-throwing overload |
[edit]Return value
true if the referred-to filesystem object exists.
[edit]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.
[edit]Example
Run this code
#include <filesystem>#include <iostream> int main(){for(autoconst 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
[edit]See also
(C++17) | checks whether path refers to existing file system object (function) |
