インテル® Fortran コンパイラー 19.0 デベロッパー・ガイドおよびリファレンス
The OPENED specifier asks whether a file is connected. It takes the following form:
OPENED = od
od
Is a scalar default logical variable that is assigned one of the following values:
.TRUE.
If the specified file or unit is connected
.FALSE.
If the specified file or unit is not connected