James,

This process of PURGELINK, RENAME works on MPE/iX. What happens when you
do a purgelink on a program file that is running by someone, is that
now, from their point of view the program file now exists in the NEW
file domain. When the last person closes the file, it will be deleted.
But only the old copy is deleted. The directory link to the original
program file was removed and a new link added to a new copy of the
program. So even while people are running the old version, the new
version can be run as a totally separate copy of the program.

Hope this explains it
John Zoltak
North American Mfg Co

> -----Original Message-----
> From: James Clark, Jr. [mailto:[log in to unmask]]
> Sent: Thursday, February 25, 1999 11:25 AM
> To: [log in to unmask]
> Subject: Re: [HP3000-L] MPE Posix utility?
>
>
> I believe his question pertained to the error you get when trying to
> overwrite a file, program file, while it is in use. You could
> have done this
> on some versions of UNIX. I remember looking at a ATT machine
> and one of the
> options was when programmer was done and put program in place
> for use that
> old users were still using the old version and new users
> would use the new
> version. When the old users exited the program and ran it
> again, they would
> get the new version. I don't believe this is possible on the
> HP Unix or MPE
> because HP maps the executable straight into memory, no
> copies. When I asked
> the ATT sales person how the above worked, he answered that
> when a user ran
> a program the program was copied into his user space and run
> from there. And
> when he exited the program was destroyed. HP on the other
> hand has been
> mapping and/or loading the executable directly from where it
> is located on
> disk, thus giving you the error when attempting to replace it
> while it is in
> use.
> An option would be to have a script (UDC) that would test for
> new versions
> and check old versions for update and when user count is zero
> move new code
> into place and return users to given program and when the
> user count of the
> new program is zero delete it. Shouldn't be too difficult to code.
>
> James
>
> > -----Original Message-----
> > From: HP-3000 Systems Discussion [mailto:[log in to unmask]]On
> > Behalf Of Andreas Schmidt
> > Sent: Thursday, February 25, 1999 10:51 AM
> > To: [log in to unmask]
> > Subject: Re: MPE Posix utility?
> >
> >
> > try mv
> >
> >      NAME
> >           mv -- rename and move files and directories
> >
> >      SYNOPSIS
> >           mv [-fi] file1 file2
> >
> >           mv [-fi] file...  directory
> >
> >           mv -R|-r [-fi] directory1 directory2
> >
> >
> > Best regards, Andreas Schmidt, CSC, Germany
> >
> >
> >
> >
> >
> > [log in to unmask] on 02/25/99 04:27:56 PM
> >
> > Please respond to [log in to unmask]
> >
> > To:   [log in to unmask]
> > cc:    (bcc: Andreas Schmidt/HI/CSC)
> > Subject:  MPE Posix utility?
> >
> >
> >
> >
> > What is the name and syntax of the Posix utility that
> allows you to assign
> > a new file, that is given the same name as the one you are
> replacing, and
> > the new file will replace the old file when the last user
> closes it?  I'm
> > looking to use it to replace a production file while users
> are on the
> > system without asking them to log off then back on to
> change the file.
> > I've seen it and used it but am unable to recall the name.
> > TIA,
> > tom renz
> >
>