Attempt to return the underlying operating system error code or error number that caused the most recent I/O error or failure to open a file. The return value is OS-dependent. For example, on unix systems, after sqlite3_open_v2() returns SQLITE_CANTOPEN, this interface could be called to get back the underlying "errno" that caused the problem, such as ENOSPC, EAUTH, EISDIR, and so forth.
See also lists of Objects, Constants, and Functions.
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