411 REFERENCE · Wikibooks
C++ Language/Std/FilesystemAccess/SizeOfFile
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
There are two ways of measuring a file's size.
Either call _filelength(), or access the st_size data member of an object returned by _fstat().
Additional information about measuring the size of a file