22.214.171.1240 OPEN-FILE FILE
Open the file named in the character string specified by c-addr u, with file access method indicated by fam. The meaning of values of fam is implementation defined.
If the file is successfully opened, ior is zero, fileid is its identifier, and the file has been positioned to the start of the file.
Otherwise, ior is the implementation-defined I/O result code and fileid is undefined.