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 READ specifier asks whether a file can be read. It takes the following form:
READ = rd
rd
Is a scalar default character variable that is assigned one of the following values:
'YES'
If the file can be read
'NO'
If the file cannot be read
'UNKNOWN'
If the processor cannot determine whether the file can be read