Linux dpkg Software Report

[Tim Frost]

On Thu, 2009-12-24 at 03:02 -0800, Ray Parrish wrote:
> Tim Frost wrote:
> > On Tue, 2009-12-22 at 21:25 -0800, Ray Parrish wrote:
> >   
> >> Hello,
> >>
> >> I hope I won't get flamed for this, but I have just completed my most 
> >> ambitious script to date, and have completed the Linux dpkg Software 
> >> Report script which takes output from dpkg, and formats it into html 
> >> pages sorted by package section, such as Games, Editors, etc... and also 
> >> generates an alphabetical index to the packages.
> >>     
> >
> > Nice effort.
> >
> >
> > One issue with the script as written is that it MUST be invoked with an
> > absolute path name (i.e,
> > "/home/tim/bin/SoftwareReport/LinuxdpkgSoftwareReport.sh", rather than
> > "LinuxdpkgSoftwareReport.sh" or
> > "./bin/SoftwareReport/LinuxdpkgSoftwareReport.sh" - which I tried
> > first).  This is used to:
> > - locate support scripts
> > - determine where to write the output files
> >   
> Is /home/tim/bin in your PATH environment variable on your system? If it 
> is, and you installed the script there, it should run, unless the script 
> does not have write priveleges in that folder.

Yes, the directory /home/tim/bin is in my path.  But I installed in the
directory /home/tim/bin/SoftwareReport, to keep this package isolated,
and I didn't add that directory to my path.

> 
> I do not know of any way to make the script itself be recognized without 
> the path name unless it is installed somewhere that is on the PATH 
> variable's definition. Perhaps you could enlighten me as to a method of 
> doing this?
> > Ideally, the program should be able to locate itself, and then derive
> > the location of the support scripts, based on its location.
> >   
> Which it does, it checks it's own name and path to find out where it has 
> been executed from, and then creates the folder structure it needs, and 
> creates the report files in those folders where ever it is ran from.

OK.  I added the install directory /home/tim/bin/SoftwareReport to my
path, and it is now working with just the script name - I see that the
system is running
 'bash /home/tim/bin/SoftwareReport/LinuxdpkgSoftwareReport.sh'

so the script can see it's full path name, despite the fact that the
command line I typed was 'LinuxdpkgSoftwareReport.sh'.



> > It should also use the user's preferred temp directory (or /tmp
> > or /var/tmp), rather than writing files to a directory under it's
> > install location.
> >   
> I was not aware that this could be done without running the script with 
> sudo, and thought it would be safer for people to have it writing files 
> into folders they were allowed to write to without administrative 
> privileges, so it cannot write to administrative areas of the drive 
> structure.

/tmp and /var/tmp can be written to by any user.  This means that you
could create a report directory and files under either of those
directories.  The only constraint is that a file (or directory) can only
be removed by the owner, or by root/sudo.

You can also write into the user's home directory (accessed as $HOME).
By convention, packages that write configuration files (or store data
long-term, such as evolution mail folders) in the user home directory
create a directory named for the package, with a leading '.' which hides
the directory from default list commands.

So you could use $HOME/.SoftwareReport or $HOME/.softwarereport as the
destination location.





> > This allows an admin to install the scripts in a system directory such
> > as /usr/bin, without needing to compromise system security.
> >   
> If I do that do I need to give root permission to execute the script?

If this tool gets packaged so that it can be installed
in /usr/local/bin (or /usr/bin, or any other location in the path for
all users), you need to ensure that any user on the system can run it.
This means that it will need to have 755 permissions (rwx for owner, and
r-x for group and others).

If that level of packaging is desired, the background JPEG should be
moved to an images directory, because it doesn't really belong in a
binaries directory.

>  
> And where do I write it's output files to, /tmp  again? I actually 
> prefer to write them to my personal user space, but I would like to be 
> up to speed on normal practice for Linux, and am rather new to it so I 
> did not know this was considered to be a requirement.

Different people have different ideas here.

Some people consider that /tmp and /var/tmp are intended for data that
can vanish at any time. (For example, in Solaris /tmp is guaranteed to
vanish on reboot).

Persistent data that belongs to me should be written to my home
directory.  Examples include:
* personalised application settings and preferences,
* mail files (evolution stores its files in .evolution/mail)
* web browser cache and history, etc


In this case, the factors for consideration are:
* the program creates a new report every time it runs
* I (as the user) may want to refer to yesterday's report,
	 rather than generating a new report.
* Should all users (on a multi-user system) be able to
	view the report?

The first two factors imply that the report should not be stored in /tmp
or /var/tmp, as they may be cleared on a reboot.


The last question is probably out of scope at present, but could be a
consideration in the future (in that case, the report might be created
by a cron job, and stored in a public, world-readable location such
as /var/cache/softwarereport)



> >
> >
> > Tim
> >   
> Thanks again, Ray Parrish
> 
> 

Tim


-- 
Tim Frost <timfrost at xtra.co.nz>
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