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- DUPUSR.ASM 22-Nov-81 7385
- Duplicate a CP/M file entry on multiple levels
- without recopying the entire file to each.
-
-
- This program creates extra entries in a CP/M 2.x
- directory that "point to" files which were actually created in a
- different directory. This gives you access to the file from
- both user numbers without having to keep multiple copies of the
- actual file itself. To create duplicate entries on drive "d" for
- user "x" from files which currently reside at user "y", type:
- A>USER y ;log in to originating user y
- A>DUPUSR d:filename.typ x ;create files at destination user x
- Note that this program will totally duplicate the directory entry in
- all respects (except the user number, of course). This means that
- both entries will show the file with the same attributes, such as
- "read-only" or "system". The filename.typ may contain "?" and "*".
-
- The only known hazard in the use of this program occurs when erasing
- one of the duplicate entries. You must type control-c immediately
- after erasing the entry, so that cp/m is forced to rebuild the allocation
- vector for that drive. This is because the erase command frees the
- blocks shown for the erased file without checking if they are in use
- elsewhere. If you didn't type control-c, the next disk write would
- clobber these blocks, voiding all other pointers to the file.
- Unfortunately this would only be apparent the next time you tried
- to read the file from another user number, at which time you would
- read garbage.
-
- Please forward all comments, suggestions and improvements to:
- Bruce R. Ratoff
- 80 Gill Lane, Apt 1B
- Iselin, New Jersey