Files opened without an explicit ACTION= specifier#
The Fortran standard says that if an OPEN
statement is executed
without an explicit ACTION=
specifier, the default value is
processor dependent. GNU Fortran behaves as follows:
Attempt to open the file with
ACTION='READWRITE'
If that fails, try to open with
ACTION='READ'
If that fails, try to open with
ACTION='WRITE'
If that fails, generate an error