The DECC$EXEC_FILEATTR_INHERITANCE feature logical affects child
    processes that are C programs.
    For versions of OpenVMS before Version 7.3-2, DECC$EXEC_FILEATTR_
    INHERITANCE is either enabled or disabled:
    o  With DECC$EXEC_FILEATTR_INHERITANCE enabled, the current file
       pointer and the file open mode is passed to the child process
       in exec calls.
    o  With this logical name disabled, the child process does not
       inherit append mode or the file position.
    For OpenVMS Version 7.3-2 and higher, DECC$EXEC_FILEATTR_
    INHERITANCE can be defined to 1 or 2, or be disabled:
    o  With DECC$EXEC_FILEATTR_INHERITANCE defined to 1, a child
       process inherits file positioning for all file access modes
       except append.
    o  With DECC$EXEC_FILEATTR_INHERITANCE defined to 2, a child
       process inherits file positioning for all file access modes
       including append.
    o  With DECC$EXEC_FILEATTR_INHERITANCE disabled, a child process
       does not inherit the file position for any access modes.