Re: HOME not set when printing with LPR

[James Richard Tyrer]

Enrique Perez-Terron wrote:
> On Wed, 2004-08-18 at 23:56, James Richard Tyrer wrote:
>
> > I was having a problem with LPR (I am still using GNUlpr) not finding my fonts 
> > when I printed.  I found that the filter script was not a login script.  I 
> > changed that but found that it still didn't find the fonts in $HOME/.fonts.
> >
> > Some debugging and I found that the problem is that despite the fact that USER 
> > is set correctly to the user that started the print job that HOME is not set (it 
> > is blank).  This appears to me to be a Bash bug.
>
>
> An lpr filter script does not usually run as the user who invoked lpr.

Actually it does in the original UCB LPR.  A job is printed by a process which 
is forked and this is run as the user that submitted the job.  The current LPRng 
appears to be a complete rewrite and does not appear do this.

> It usually runs with the privileges that the lpd daemon allows it to
> have. You might want to modify lpd to set HOME for the filter processes
> to point to the home directory of the user who submitted the print job.

If I understood the LPRng code correctly from a quick scan, it has a process for 
the filter, so it would need to be modified to run a separate filter process for 
each user.  The original design is clearly better.

> HOME is usually set (exported) by the /bin/login program or its
> replacements like xdm, gdm, etc.

Yes, but this doesn't set it when it is started with an effective user by a 
fork.

> Lpd is usually started from an init script. Then there is no login
> program in the hierarchy of parent processes of Lpd.

But, this doesn't just apply to LPR.

Bash *does* have code to set HOME (from the passwd file) when it is not set. 
This is needed for Tilde expansion.  The problem appears to be that when a 
script is a login script that this value is not passed to: "/etc/profile" and 
"~/.bash_profile".  This is the problem and this is the bug that needs to be 
fixed.  I should emphasize that when "~/.bash_profile" is called that HOME is 
set correctly (internally) otherwise it wouldn't be able to call the correct script!

--
JRT