[Coco] OS9 Arc

[William Carlin]

Bill,

If you do a DriveWire to DriveWire disk copy you can see that arc does
re-read the file that was just copied when using the verify option.  But
the source file is not read a second time.  This is what led me to believe
some kind of checksum is used to do the verify.  I was wondering if the
programmer used a shortcut and just utilized the built in CRC OS9 function
call to perform this check.  I would be interested in that source code if
you can find it.

William


On Wed, Jan 4, 2017 at 9:55 PM, L. Curtis Boyle <curtisboyle at sasktel.net>
wrote:

> Ah, thanks for the correction. This one sounds more like the STREAM
> utility Bruce Isted did, that we used for years (I still do, on occasion).
>
> Sent from my iPhone
>
> > On Jan 4, 2017, at 8:20 PM, Bill Pierce via Coco <coco at maltedmedia.com>
> wrote:
> >
> > Curtis, this isn't the "archiving" utility "dearc", it's a disk copy
> utility called "arc" (as in arching files from one disk to another). It
> checks the last modified date and keeps the newest version when a duplicate
> exists on the disk.
> > Here's the usage from arc:
> >
> > Usage: arc [-acdeflmuv] from_dir to_dir
> >     a = all files
> >     c = confirm file if not there
> >     d = confirm non-existant directory
> >     e = confirm existing directory
> >     f = prevent copy of files
> >    ln = only n levels of the tree (1..9)
> >     m = do multilple (all) directories
> >     v = verify the copy
> >     u = force uppercase for comparisons
> >
> > As you can see, it copies files, directories, subdirectories, etc
> > It's not an archiving util like zip or lzh.
> >
> >
> >
> >
> >
> >
> > Bill Pierce
> > "Charlie stole the handle, and the train it won't stop going, no way to
> slow down!" - Ian Anderson - Jethro Tull
> >
> >
> >
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> >
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> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: L. Curtis Boyle <curtisboyle at sasktel.net>
> > To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> > Sent: Wed, Jan 4, 2017 7:40 pm
> > Subject: Re: [Coco] OS9 Arc
> >
> > Going off old memory, I am pretty sure it is a CRC check, like LHA and
> ZIP. Sent from my iPhone> On Jan 4, 2017, at 5:36 PM, William Carlin <
> whcarlinjr at gmail.com> wrote:> > I am continually amazed at the resiliency
> and speed of the OS9 Arc> command.  I discovered it was one of the included
> binaries on Bill's "XRoar> Coco 2b Becker Port Starter Kit".  Now I am
> flabbergasted that this program> works so well within the memory
> constraints of the 64k Color Computer.> > I have always wondered about the
> "verify" option in this program.  It does> not appear to be doing a "byte
> by byte" comparison of the source and> destination files like the cmp
> command does.  Does this program use some> kind of checksum to determine if
> the destination file is different from the> source?  Is the source code for
> this program available somewhere online?  I> checked though my extensive
> archives of OS9 software and can only find the> binary archive but no
> source code.> > William> > CoCo 4 ever> > -- > Coco mailing list>
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