There is one entry in the SYSVOLUMES file for every volume (logical or physical) that has been attached during the current session. This includes several system volumes such as REVBOOT (the logical name for the current default drive), DOS (the logical DOS file), MEMORY.RESIDENT (RTP50, the BFS for SYSVOLUMES and SYSTABLES), and INDEXING. The information is stored at run time in the @VOLUMES array.
Entries in the SYSVOLUMES file have five fields. These are:
Field Number | Description |
0 (key) | Volume Name. This is the name under which the volume was attached. For example, if a user has attached the volume \TEMP\, the name \TEMP\ will be the key to a record in the SYSVOLUMES file. |
1 | Media Name. The internal media name for the volume. This name is used to ensure the uniqueness of data file names. The media name guarantees that a user cannot attach the same volume using two different names such as \TEMP\ and C:\TEMP. |
2 | Qualifier. Usually used for the DOS path name of the media map for the volume. However, each BFS can use the qualifier in any manner it finds suitable. |
3 | File List. A list of files currently available (attached) on that volume (delimited with @VM). |
4 | Filing System(s). The MFS/BFS list for that volume (delimited with @VM). This is normally only the BFS name (for example, RTP57). However, if an MFS has been installed using a volume pointer, its name will appear in this field. |
5 | Media Handle. The handle used to access the media map for the volume. This handle is created by the OPEN.MEDIA call, and is passed in subsequent READ.MEDIA and WRITE.MEDIA calls. |
