[Coco] No easy rename on OS-9 ?

[Gene Heskett]

On Friday 28 March 2014 19:20:57 Luis Antoniosi (CoCoDemus) did opine:

> it turns out that there is a mv on rtsi:
> 
> ftp://www.rtsi.com/OS9/OS9_6X09/UTILITIES/mv.ar
>
Yup, looked at it. It does the move by copying it to the target location, 
then deleting it from the source location. Needlessly complex, subject to 
disk errors etc, when all you really need to do is pick up the $20 bytes of 
the source directory entry and put it in the target directory.  The 
directory entry is moved, but not even the FD sector is moved.  Then go 
back and null the first byte of the source dir, and to be complete, run 
dsort on both directories.

> There is also a cp and a ls.
> 
> On Wed, Mar 26, 2014 at 5:09 PM, Gene Heskett <gheskett at wdtv.com> wrote:
> > On Wednesday 26 March 2014 16:30:52 Luis Antoniosi (CoCoDemus) did 
opine:
> >> I'm very disappointed to discover that there ain't no I$Rename on
> >> OS-9. This is the reason the file becomes empty on cp/m wordstar
> >> save. As it tries to rename the scratch file and doesn't find it, it
> >> makes a new one. I was ignoring the BDOS rename call.
> >> 
> >> The rename.asm from os-9 repo is pretty large. I can make a smaller
> >> copy/delete but this is not the optimal solution and could run out of
> >> space.
> >> 
> >> As far I understood the rename.asm, it opens a directory raw file and
> >> change the name on it ? Is that correct ? Is it safe with multi
> >> threading doing this way ? What could be the other solution ? Using
> >> fork to create a rename process ?
> > 
> > I think so. One could fork the rename module.  But I just looked at
> > rename.asm and while it may work, what its doing makes relatively
> > little sense to me.
> > 
> > In fact, if I find the time, I might re-write a new rename/mv utility.
> > 
> > Basic outline:
> > 1. allocate 3 $20 byte buffers, and 4 256 byte buffers. that won't be
> > all, but the rest will be appended when the need arises.
> > 2 strncpy old name to 256 byte buffer 1
> > 3 strncpy new name to 256 byte buffer 2
> > 4 save pwd
> > 5 parse the 1st buffer to extract the ending filename
> > 6 strncpy it to the first $20 byte buffer and the 3rd one too
> > 7 parse the 2nd buffer to extract the ending filename
> > 8 strncpy that to the 2nd $20 byte buffer.
> > 9 parse the 1st 256 byte buffer to get the path to the directory
> > 10 put that in 256 byte buffer 3
> > 11 parse the 2nd 256 byte buffer for the path to that directory
> > 12 save it in 256 byte buffer 4
> > 13 set attrs for a directory and open the pathlist for 256 byte buffer
> > 3 14 setup a read loop, using the 3rd buffer as cache to look for the
> > name in buffer 1, or terminate with an E$FNF if not found.
> > 15 when the match is found, strncpy 29 bytes from buffer 2 to buffer
> > 3. You do not want to destroy the FD's address.
> > 
> > Now, if NOT doing a move, seek back $20 bytes on that path and write
> > the $20 bytes of buffer 3.  Clean up and go home.  If doing the move,
> > null the first byte of buffer 1 and write its $20 bytes back instead.
> > 
> > Now for the move. open the pathlist in the 2nd 256 byte buffer as a
> > directory and seek to EOF.  Write the $20 bytes of buffer 3.  Close
> > both directory files.  Then, just for S&G's fork a dsort against both
> > pathlists, one at a time.
> > 
> > Clean up and go home.
> > 
> > Cheers, Gene
> > --
> > 
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > 
> > -Ed Howdershelt (Author)
> > Genes Web page <http://geneslinuxbox.net:6309/gene>
> > 
> > 
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco


Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>