Function builtin_file_mtime 

fn builtin_file_mtime(
    args: &[RValue],
    _named: &[(String, RValue)],
    context: &BuiltinContext<'_>,
) -> Result<RValue, RError>

Get file modification times as POSIXct timestamps (seconds since Unix epoch).

@param … character scalars: file paths to query @return double vector of modification times (NA for non-existent files)