std::experimental::filesystem:: file_size
From cppreference.com
<
cpp
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experimental
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fs
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Defined in header
<experimental/filesystem>
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||
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std::
uintmax_t
file_size
(
const
path
&
p
)
;
std:: uintmax_t file_size ( const path & p, error_code & ec ) ; |
(1) | (filesystem TS) |
Returns the size of the regular file
p
, determined as if by reading the
st_size
member of the structure obtained by POSIX
stat
(symlinks are followed).
Attempting to determine the size of a directory (as well as any other file that is not a regular file or a symlink) is treated as an error.
The non-throwing overload returns returns - 1 on errors.
Parameters
| p | - | path to examine |
| ec | - | out-parameter for error reporting in the non-throwing overload |
Return value
The size of the file, in bytes.
Exceptions
The overload that does not take an error_code & parameter throws filesystem_error on underlying OS API errors, constructed with p as the first argument and the OS error code as the error code argument. std:: bad_alloc may be thrown if memory allocation fails. The overload taking an error_code & parameter sets it to the OS API error code if an OS API call fails, and executes ec. clear ( ) if no errors occur. This overload has
noexcept
specification:
noexcept
Example
Run this code
#include <experimental/filesystem> #include <fstream> #include <iostream> namespace fs = std::experimental::filesystem; int main() { fs::path p = fs::current_path() / "example.bin"; std::ofstream(p).put('a'); // create file of size 1 std::cout << "File size = " << fs::file_size(p) << '\n'; fs::remove(p); try { fs::file_size("/dev"); // attempt to get size of a directory } catch (fs::filesystem_error& e) { std::cout << e.what() << '\n'; } }
Possible output:
File size = 1 filesystem error: cannot get file size: Is a directory [/dev]
See also
|
changes the size of a regular file by truncation or zero-fill
(function) |
|
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determines available free space on the file system
(function) |