READONLY

 READONLY

 Prohibits WRITE access to the file.  Enables users with READ access
 to access the file.

 READONLY is similar to specifying ACTION='READ', but READONLY
 prevents deletion of the file if it is closed with STATUS='DELETE'
 in effect.

 Default file access privileges are READWRITE, which can cause
 run-time I/O errors if the file protection does not permit write
 access.

 The READONLY specifier has no effect on the protection specified
 for a file.  Its main purpose is to allow a file to be read
 simultaneously by two or more programs.  For example, use READONLY
 if you wish to open a file so you can read it, but you also want
 others to be able to read the same file while you have it open.