The current Triumf DAQ standard (Midas) since the second quarter of this
year (2003) has the capability to deal with ROOT histograms. The internal
midas logger can save data files in ROOT format and the analyzer can book
and fill ROOT histograms. These features triggered a new project started
during summer 2003 for building a Triumf GUI ROOT/Midas display utility.

The initial requirements for this utility are:
1) Solely based on ROOT (VirtualX, no Qt)
2) Similar overall functionality than PAW.
   - Open concurrent ROOT files.
   - Open connection to a single Midas Online experiment (requires analyzer
                                                          as server)
   - Optional Auto-update in ONLINE mode.
   - Zoning, Zooming option display.
   - Simple Historgram gaphic manipulation. (based on current ROOT
                                             implementation)
   - Tree manipulation ( use of TBrowser())
   - Simple user script invocation.
   - Optional experiment specific customization.
3) Session configuration save/restore option.

An initial version has been developed and currently is under evaluation.
Improvement and further development will based on the local experimenters
responses. 

This utility will be available for external use around the second quarter of
the 2004 at the latest.

.

Updating the instructions to ROOT version 3.10.2. Example is from TRIUMF-KOPIO
tree analysis.

shell> root -l
root> TFile *f = new TFile("run00064.root")
root> Trigger->MakeSelector("TriggerSelector")  // "Trigger" is the tree name
inside the root file. Generates TriggerSelector.h and TriggerSelector.cpp

= edit run.C, the main program:

{
gROOT->Reset();
TSelector *s = TSelector::GetSelector("TriggerSelector.C");

TChain chain("Trigger"); // "Trigger" is the tree name inside the root files
chain.Add("run03016.root"); // can chain multiple files

TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);

chain.Process(s,"",500); // process 500 events
//chain.Process(s); // or process all events

tdc2->Draw();
}

= edit TriggerSelector.h:

in the TriggerSelector class members, i.e. "UInt_t TDC1_TDC1[47];" edit the
array size to be bigger than the maximum possible bank size

= edit TriggerSelector.C:

Bool_t TriggerSelector::Process(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);

  if (entry%100 == 0)
    printf("process %d, nTDC %3d, 0x%08x\n",entry,TDC1_nTDC1,TDC1_TDC1[1]);

  tdc2->Fill(TDC1_nTDC1);
  return kTRUE;
}

= Run the analysis:

shell> root -l
root> .x run.C
 
K.O.

> root -l
root> TFile *f = new TFile("run00064.root")
root> TTree *t = f->Get("Trigger")
root> t->StartViewer() // look at the ROOT TTree
root> t->MakeSelector() // generates Trigger.h, Trigger.C

edit run.C, the main program:
{
gROOT->Reset();
TFile f("data/run00064.root");
TTree *t = f.Get("Trigger");

TH1D* adc8 = new TH1D("adc8","ADC8",1500,0,1500-1);
TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);
TH2D* h12 = new TH2D("h2","ADC8 vs TDC2",100,0,1500,100,0,1500);
TH2D* h12cut = new TH2D("h2cut","ADC8 vs TDC2",50,0,1000-1,50,0,1500);

TSelector *s = TSelector::GetSelector("Trigger.C");
t->Process(s);

adc8->Draw();
tdc2->Draw();
h12->Draw();
h12cut->Draw();
}

edit Trigger.C:

Bool_t Trigger::ProcessCut(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);
  if (entry%100 == 0) printf("entry %d\r",entry);
  return kTRUE;
}

void Trigger::ProcessFill(Int_t entry)
{
  adc8->Fill(ADCS_ADCS[8]);
  tdc2->Fill(TDCS_TDCS[2]);
  h12->Fill(TDCS_TDCS[2],ADCS_ADCS[8]);
  if (ADCS_ADCS[8] > 100)
    h12cut->Fill(TDCS_TDCS[2],ADCS_ADCS[8]);
}

Run the analysis:

root -l
root> .x run.C

K.O.

Updating the instructions to ROOT version 3.10.2. Example is from TRIUMF-KOPIO
tree analysis.

shell> root -l
root> TFile *f = new TFile("run00064.root")
root> Trigger->MakeSelector("TriggerSelector")  // "Trigger" is the tree name
inside the root file. Generates TriggerSelector.h and TriggerSelector.cpp

= edit run.C, the main program:

{
gROOT->Reset();
TSelector *s = TSelector::GetSelector("TriggerSelector.C");

TChain chain("Trigger"); // "Trigger" is the tree name inside the root files
chain.Add("run03016.root"); // can chain multiple files

TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);

chain.Process(s,"",500); // process 500 events
//chain.Process(s); // or process all events

tdc2->Draw();
}

= edit TriggerSelector.h:

in the TriggerSelector class members, i.e. "UInt_t TDC1_TDC1[47];" edit the
array size to be bigger than the maximum possible bank size

= edit TriggerSelector.C:

Bool_t TriggerSelector::Process(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);

  if (entry%100 == 0)
    printf("process %d, nTDC %3d, 0x%08x\n",entry,TDC1_nTDC1,TDC1_TDC1[1]);

  tdc2->Fill(TDC1_nTDC1);
  return kTRUE;
}

= Run the analysis:

shell> root -l
root> .x run.C
 
K.O.

> root -l
root> TFile *f = new TFile("run00064.root")
root> TTree *t = f->Get("Trigger")
root> t->StartViewer() // look at the ROOT TTree
root> t->MakeSelector() // generates Trigger.h, Trigger.C

edit run.C, the main program:
{
gROOT->Reset();
TFile f("data/run00064.root");
TTree *t = f.Get("Trigger");

TH1D* adc8 = new TH1D("adc8","ADC8",1500,0,1500-1);
TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);
TH2D* h12 = new TH2D("h2","ADC8 vs TDC2",100,0,1500,100,0,1500);
TH2D* h12cut = new TH2D("h2cut","ADC8 vs TDC2",50,0,1000-1,50,0,1500);

TSelector *s = TSelector::GetSelector("Trigger.C");
t->Process(s);

adc8->Draw();
tdc2->Draw();
h12->Draw();
h12cut->Draw();
}

edit Trigger.C:

Bool_t Trigger::ProcessCut(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);
  if (entry%100 == 0) printf("entry %d\r",entry);
  return kTRUE;
}

void Trigger::ProcessFill(Int_t entry)
{
  adc8->Fill(ADCS_ADCS[8]);
  tdc2->Fill(TDCS_TDCS[2]);
  h12->Fill(TDCS_TDCS[2],ADCS_ADCS[8]);
  if (ADCS_ADCS[8] > 100)
    h12cut->Fill(TDCS_TDCS[2],ADCS_ADCS[8]);
}

Run the analysis:

root -l
root> .x run.C

K.O.

Updating the instructions to ROOT version 3.10.2. Example is from TRIUMF-KOPIO
tree analysis.

shell> root -l
root> TFile *f = new TFile("run00064.root")
root> Trigger->MakeSelector("TriggerSelector")  // "Trigger" is the tree name
inside the root file. Generates TriggerSelector.h and TriggerSelector.cpp

= edit run.C, the main program:

{
gROOT->Reset();
TSelector *s = TSelector::GetSelector("TriggerSelector.C");

TChain chain("Trigger"); // "Trigger" is the tree name inside the root files
chain.Add("run03016.root"); // can chain multiple files

TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);

chain.Process(s,"",500); // process 500 events
//chain.Process(s); // or process all events

tdc2->Draw();
}

= edit TriggerSelector.h:

in the TriggerSelector class members, i.e. "UInt_t TDC1_TDC1[47];" edit the
array size to be bigger than the maximum possible bank size

= edit TriggerSelector.C:

Bool_t TriggerSelector::Process(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);

  if (entry%100 == 0)
    printf("process %d, nTDC %3d, 0x%08x\n",entry,TDC1_nTDC1,TDC1_TDC1[1]);

  tdc2->Fill(TDC1_nTDC1);
  return kTRUE;
}

= Run the analysis:

shell> root -l
root> .x run.C
 
K.O.

> root -l
root> TFile *f = new TFile("run00064.root")
root> TTree *t = f->Get("Trigger")
root> t->StartViewer() // look at the ROOT TTree
root> t->MakeSelector() // generates Trigger.h, Trigger.C

edit run.C, the main program:
{
gROOT->Reset();
TFile f("data/run00064.root");
TTree *t = f.Get("Trigger");

TH1D* adc8 = new TH1D("adc8","ADC8",1500,0,1500-1);
TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);
TH2D* h12 = new TH2D("h2","ADC8 vs TDC2",100,0,1500,100,0,1500);
TH2D* h12cut = new TH2D("h2cut","ADC8 vs TDC2",50,0,1000-1,50,0,1500);

TSelector *s = TSelector::GetSelector("Trigger.C");
t->Process(s);

adc8->Draw();
tdc2->Draw();
h12->Draw();
h12cut->Draw();
}

edit Trigger.C:

Bool_t Trigger::ProcessCut(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);
  if (entry%100 == 0) printf("entry %d\r",entry);
  return kTRUE;
}

void Trigger::ProcessFill(Int_t entry)
{
  adc8->Fill(ADCS_ADCS[8]);
  tdc2->Fill(TDCS_TDCS[2]);
  h12->Fill(TDCS_TDCS[2],ADCS_ADCS[8]);
  if (ADCS_ADCS[8] > 100)
    h12cut->Fill(TDCS_TDCS[2],ADCS_ADCS[8]);
}

Run the analysis:

root -l
root> .x run.C

K.O.

> Where should MIDAS be installed?

I personally don't have any preference, as long as it's in accordance with "the standard"
(whatever this is). Maybe one should add a flag to the makefile to specify the
installation directory, either /opt or /usr/local, so people then have the choice. I have
seen that in other packages. As for the RPM, I leave the final proposal to the person
writing the spec file (Paul? Piotr? Konstantin?). We should then commonly agree on the
location based on that proposal. The person supplying the RPM will "officially" become the
RPM maintainer and be responsible for maintaining it.

> installed in /sbin/, /bin/, or /usr/. System administrators can build packages from
> source and install them into the /usr/local/ directory. However, third-party packages
> of add-on software must be installed in /opt/<package>/, where <package> is the name
> that describes a software suite.

Well, midas is kind of in the middle. On one hand it's a third-party package (-> /opt),
but it requires some compilation to allow meaningful work (frontend, analyzer). So maybe
the RPM should go to /opt, and if compiled from the TAR ball it should go to /usr/local?
But that means if someone has to maintain a large basis of midas machines, he/she has to
always search two locations. On the other hand one can alway do a "cd $MIDASSYS" ...

- Stefan

> > Starting from midas version 1.9.4 on, the environment variable 'MIDASSYS' ...
> 2. What will the entire structure tree look like?
> 
> Here's my suggestion
> MIDASSYS=/opt/midas-1.9.4 (for example)   

Where should MIDAS be installed?

After looking at the LSB and at the FHS, it appears that the standards permit all of:
1) /opt/midas...
2) /usr/{bin,lib,...}
3) /usr/local/{bin,lib,...}

Some handy references:
http://www.pathname.com/fhs/pub/fhs-2.3.html
http://www.linuxbase.org/spec/

The "example LSB-compliant packages" appear to install into /opt/lsb, but I do not see
 any guidance as to where "my" packages should go.

Then, after some googling, I see that IBM "recommends" /opt (see
http://www-106.ibm.com/developerworks/linux/library/l-lsb.html):

begin-quote---
To avoid name space collisions when installing LSB-conforming applications, the
applications belonging to the base operating system or the distribution are to be
installed in /sbin/, /bin/, or /usr/. System administrators can build packages from
source and install them into the /usr/local/ directory. However, third-party packages
of add-on software must be installed in /opt/<package>/, where <package> is the name
that describes a software suite.
end-quote---


K.O.

> > Are we ready for 2.0? 

I disapprove of version number inflation. Why not go straight for midas version
3000-Pro-Z?

> A big thing along the horizon I see is the ROME environment
> (http://midas.psi.ch/rome/). So we will move away from PAW to ROOT. Although
> the DAQ part will stay untouched, the whole analysis back-end changes,
> including some XML configuration and MySQL support.

I looked at the ROME slides from Pierre, and it seems to suffer badly from the
second-system syndrome (read The Mythical Man-Month).

For us, it is important to get the data into a form where we can process it with
ROOT and I would prefer if we could concentrate in improving the (embryonic) ROOT
online analysis capabilities.

> > 1) For one I would like to explore memory mapping (mmap())

It is trivial to replace System-V shared memory with mmap(). I am surprised that
it has not been done yet. System-V semaphores are a little bit harder to get rid of.

> > 2) Expanding hardware support: 
> >    a) custom microcontrolers?
> >    b) more hardware
> >    c) how about a "standard" Linux device /dev/midas
> >    for various PCI cards (PCI<->CAMAC) (PCI<->VME) 

We cannot expect MIDAS Authors to provide drivers for all possible hardware.

At best, we can mount an effort to collect exisiting drivers from all MIDAS users
"out there" and to integrate them into MIDAS.

Even that is highly non-trivial- many drivers use non-portable native hardware
access interfaces (direct bit-banging on PPCs, VMIC library on VMIC Linux
machines, etc). We have already failed to create an efficient generic portable VME
access library.

> As for a), there is the MSCB system (http://midas.psi.ch/mscb)

I never saw the point of having tons of MIDAS code for MSCB hardware that nobody
has and nobody will ever have.

> > 3) I have never really seen a midas deployment that uses interrupts. 
>
> It's not only the "ease" of polling, but also that it's faster (in almost all
> cases) and less troublesome. But hey, interrupt support is included in mfe.c,
> so if you are fanatic about interrupts...

Interrupts are important when one cannot afford chewing up CPU cycles, memory
cycles, PCI cycles and VME cycles on polling.

As I understand, common CAMAC hardware does not generate interrupts- this explains
lack of examples and lack of interrupt use. At TRIUMF, our new VME hardware
supports interrupts and I have a VMIC-based setup where I can (and intend to) test
MIDAS support of interrupts.

K.O.

Hello midas'ers,

Today I discovered a severe bug in the routine bm_check_buffers(), which
causes the logger to crash when it stops a run due to a reached event limit.
The funny thing is that this bug was there since the beginning, but only
recent versions of gcc and libc reveal it.

Since I consider this severe, I fixed it and updated 1.9.4 just now. I did
not go with 1.9.4-1, but maybe in future we should consider patch levels.

So please everybody who uses 1.9.4 and has problems with crashing loggers,
please update to 1.9.4 from today (July 15th, 2004).

- Stefan

Have changed your entry as Non-HTML (easier to reply to...)

Here are some "initial" comments, by no means complete...

> Are we ready for 2.0? 
> Stefan - do you have any ideas/enhancements?

A big thing along the horizon I see is the ROME environment
(http://midas.psi.ch/rome/). So we will move away from PAW to ROOT. Although
the DAQ part will stay untouched, the whole analysis back-end changes,
including some XML configuration and MySQL support. I guess that would justify
a 2.0. I will discuss this at TRIUMF when I come in September, see how useful
ROME is for other users...

> 1) For one I would like to explore memory mapping (mmap()) on Linux
> - I've used it once upon a time on DEC OSF/1 and I found it really
> nice compared to shared memory. 
> From a user standpoint it behaves as a shared memory but is mapped 
> to a real file that can be easily "removed" when neccessary. 
> One really annoying thing in MIDAS is when it goes ballistic
> the cleanup which is somewhat tricky. 
> The question if there is any performance penalty associated

I guess there are no performance penalties, since under the hood both
techniques are handled similarly. The problem is that besides share memories
you need also semaphores to controll exclusive access to the memory, either
shm() funcitons or mmap(), so this would only fix half of the problem. I seem
to remember that mmap() was not available on some Ultix systems or so, but I
guess that's obsolete by now...

> 2) Expanding hardware support: 
>    a) custom microcontrolers?
>    b) more hardware
>    c) how about a "standard" Linux device /dev/midas
>    for various PCI cards (PCI<->CAMAC) (PCI<->VME) 

Well, you cannot develop hardware support for hardware you don't have, so the
policy up to now was that everyone developing some special drivers or hardware
support contributed it to the package. About c), we have already a CAMAC
driver standard, but at the user space level, so I don't see the benefit of
having kernel-mode standardized drivers. The only difference will be that the
debugging will be harder. VME standard is there in a kind of poor start right
now, but I expect to finish it this fall.

As for a), there is the MSCB system (http://midas.psi.ch/mscb) which has midas
support on the device driver and bus driver level, but I learned that
distributing hardware (or PCB designs if you like) is much harder than sharing
software. 

> 3) I have never really seen a midas deployment that uses interrupts. 
> I do understand the ease of polling and the fact that these days
> CPU's are cheap but sometimes it is important to use interrupts.
> Any examples/experience?

It's not only the "ease" of polling, but also that it's faster (in almost all
cases) and less troublesome. But hey, interrupt support is included in mfe.c,
so if you are fanatic about interrupts, please feel free to use them.

Sorry the previous message got mangled:

Hi, 
I think that rather than spending too much time on where to put files 
and how to define the environment - I am guilty of that myself -  we should 
perhaps have some discussion on the future of MIDAS. 

Are we ready for 2.0? 

Stefan - do you have any ideas/enhancements? 

1) For one I would like to explore memory mapping (mmap()) on Linux.
I've used it once upon a time on DEC OSF/1 and I found it really nice 
compared to shared memory. From a user standpoint it behaves as a shared
memory but is mapped to a real file that can be easily "removed" when 
neccessary. One really annoying thing in MIDAS is when it goes ballistic 
the cleanup is somewhat tricky. 
The question if there is any performance penalty associated 

2) Expanding hardware support: 
  a) custom microcontrolers? 
  b) other hardware
  c) how about a "standard" Linux device /dev/midas for various 
  PCI cards (PCI<->CAMAC) (PCI<->VME) 

3) I have never really seen a midas deployment that uses interrupts. 
I do understand the ease of polling and the fact that these days CPU's 
are cheap but sometimes it is important to use interrupts. 

Any examples/experience? 

?) 

Piotr

Hi,
  I think that rather than spending too much time on where to 
put files and how to define the environment - I am guilty of that myself.
We should be perhaps have some discussion on the future of MIDAS.

Are we ready for 2.0? 
Stefan - do you have any ideas/enhancements?

1) For one I would like to explore memory mapping (mmap()) on Linux
- I've used it once upon a time on DEC OSF/1 and I found it really
nice compared to shared memory. 
From a user standpoint it behaves as a shared memory but is mapped 
to a real file that can be easily "removed" when neccessary. 
One really annoying thing in MIDAS is when it goes ballistic
the cleanup which is somewhat tricky. 
The question if there is any performance penalty associated

2) Expanding hardware support: 
   a) custom microcontrolers?
   b) more hardware
   c) how about a "standard" Linux device /dev/midas
   for various PCI cards (PCI<->CAMAC) (PCI<->VME) 

3) I have never really seen a midas deployment that uses interrupts. 
I do understand the ease of polling and the fact that these days
CPU's are cheap but sometimes it is important to use interrupts.
Any examples/experience?

?)

Piotr

> With POSIX there is a written standard, which says that each pacakge goes in
> it's own
> directory under /opt. eg. /opt/midas.  Each package gets to define it's own
> structure
> within that directory.  One could imagine several versions installed at the
> same time
> /opt/midas/v1.9.2 and /opt/midas/v1.9.4 each with a bin, lib include etc. 
> Following the
> ROOT example, you could make a link from /opt/midas/pro to
> /opt/midas/v1.9.4, so that
> system files and login files are easy to maintain etc.  The basic idea is
> 
> MIDASSYS=/opt/midas/pro
> PATH=$PATH:$MIDASSYS/bin
> 
> though a more sophisticated approach is
> 
> MIDASSYS=/opt/midas/pro
> echo $PATH | grep -q $MIDASSYS || PATH=$PATH:$MIDASSYS/bin
> 
> where the assignment line (Bourne shell, and BASH shell) ensures
> that multiple entries are not added on the PATH even if the script is more
> than once.

That sounds all very good to me. So can you please sit together (at least John,
Piotr, and Pierre-Andre), discuss a common scheme and and propose it officially in
this forum for comments. After a week or so, it should be implemented into the
Makefile and installation scripts. I also would like to have Paul Knowles giving
it a look, since he voluteered to make the midas RPMs, which also heavily depends
on the chosen directory structure.

For a long time the "de facto" standard was to spread a package around in many
directories under /usr/local.  This proved to be a bad idea, as removing the
package
became very difficult.

With POSIX there is a written standard, which says that each pacakge goes in
it's own
directory under /opt. eg. /opt/midas.  Each package gets to define it's own
structure
within that directory.  One could imagine several versions installed at the
same time
/opt/midas/v1.9.2 and /opt/midas/v1.9.4 each with a bin, lib include etc. 
Following the
ROOT example, you could make a link from /opt/midas/pro to
/opt/midas/v1.9.4, so that
system files and login files are easy to maintain etc.  The basic idea is

MIDASSYS=/opt/midas/pro
PATH=$PATH:$MIDASSYS/bin

though a more sophisticated approach is

MIDASSYS=/opt/midas/pro
echo $PATH | grep -q $MIDASSYS || PATH=$PATH:$MIDASSYS/bin

where the assignment line (Bourne shell, and BASH shell) ensures
that multiple entries are not added on the PATH even if the script is more
than once.

POSIX also goes on to say that links from /opt/bin can be made if desired. 
I find this
usefull if a package has only one or two executables, and I don't to make
multiple
versions available.

I hope that the POSIX ideas are usefull,

John.

> > Here's my suggestion
> > MIDASSYS=/opt/midas-1.9.4 (for example)   
> 
> I guess we should follow the "standard" as much as possible. MIDASSYS was
inspired by
> ROOTSYS. Now where do people usually install ROOT? Is it /opt/root-x.x.x
or something
> else. Some years ago (when I did the last time some linux administration)
optional
> packages were put into /usr/local by default. I guess you have more
experience with
> today's tradition, so do whatever you thing is standard.
> 
> > so the Linux binaries would go to 
> > MIDASHOST=i386-pc-linux-gnu
> > $MIDASSYS/$MIDASHOST/bin
> > $MIDASSYS/$MIDASHOST/lib
> 
> Does that mean that the path has to be modified to include
$MIDASSYS/$MIDASHOST/bin?
> If we put a link to /usr/local/bin, the path does not have to be modified.
What about
> shared libraries? Does ldconfig know about /usr/local/lib, or
$MIDASYS/$MIDASHOST/lib?
> 
> > and the shared stuff would go to 
> > $MIDASSYS/include
> > $MIDASSYS/share/drivers
> > $MIDASSYS/share/examples
> 
> What about /usr/share? Is that a common place for documentatino etc?
> 
> Thanks for your advice.
> 
> - Stefan

> I guess we should follow the "standard" as much as possible. MIDASSYS was inspired by
> ROOTSYS. Now where do people usually install ROOT? Is it /opt/root-x.x.x or something
> else. Some years ago (when I did the last time some linux administration) optional
> packages were put into /usr/local by default. I guess you have more experience with
> today's tradition, so do whatever you thing is standard.
I agree that we should follow the standard. 
I used /opt as an example. 
There are several "schools" as to where put things my philosophy is
/usr/{bin,lib,include}       - std OS packages (RPMS, .deb or whatever your flavor likes)
/usr/local/{bin,lib,include} - make/make install packages
/opt/..                      - additional packages (RPMS, ...) 

But it should be up to the user what $MIDASSYS she/he likes.

> 
> > so the Linux binaries would go to 
> > MIDASHOST=i386-pc-linux-gnu
> > $MIDASSYS/$MIDASHOST/bin
> > $MIDASSYS/$MIDASHOST/lib
> 
> Does that mean that the path has to be modified to include $MIDASSYS/$MIDASHOST/bin?
> If we put a link to /usr/local/bin, the path does not have to be modified. What about
> shared libraries? Does ldconfig know about /usr/local/lib, or $MIDASYS/$MIDASHOST/lib?
The path could/should be modified in users .bashrc/.tcshrc or we could provide a simple
system-wide script(s) that would do the job.
For years, I've been using such a scenario on my Linux PCs with regards to various
add-on packages (e.g. cern). 

Here's an example of my cern.sh that goes into /etc/profile.d on my RedHat Linux PC
#===================================
. /etc/profile.d/.functions
export CERN=/cern
export CERN_LEVEL=pro
addpath $CERN/$CERN_LEVEL/bin
#===================================

As for library path: there are several ways (as with exec path)
a) nice way: modify /etc/ld.so.conf by adding $MIDASYS/$MIDASHOST/lib
b) modifying LD_LIBRARY_PATH (there's some security issues with it)
c) symlinking to /usr/local/lib


> 
> What about /usr/share? Is that a common place for documentatino etc?
Yes. Check any recent Linux distribution /usr/share is full of docs, icons, etc.

This is my bias. 

I (obviously) prefer packing things into rpm which makes install/updates 
very easy - especially if you are managing several machines.

Cheers
    Piotr

> Here's my suggestion
> MIDASSYS=/opt/midas-1.9.4 (for example)   

I guess we should follow the "standard" as much as possible. MIDASSYS was inspired by
ROOTSYS. Now where do people usually install ROOT? Is it /opt/root-x.x.x or something
else. Some years ago (when I did the last time some linux administration) optional
packages were put into /usr/local by default. I guess you have more experience with
today's tradition, so do whatever you thing is standard.

> so the Linux binaries would go to 
> MIDASHOST=i386-pc-linux-gnu
> $MIDASSYS/$MIDASHOST/bin
> $MIDASSYS/$MIDASHOST/lib

Does that mean that the path has to be modified to include $MIDASSYS/$MIDASHOST/bin?
If we put a link to /usr/local/bin, the path does not have to be modified. What about
shared libraries? Does ldconfig know about /usr/local/lib, or $MIDASYS/$MIDASHOST/lib?

> and the shared stuff would go to 
> $MIDASSYS/include
> $MIDASSYS/share/drivers
> $MIDASSYS/share/examples

What about /usr/share? Is that a common place for documentatino etc?

Thanks for your advice.

- Stefan

> Starting from midas version 1.9.4 on, the environment variable 'MIDASSYS'
> should be defined and point to the installation directory of midas. The
> purpose of that is that add-on packages (like the upcoming ROME system) can
> find the midas libraries and include files. It is excatly the same as for
> ROOT which defines ROOTSYS and should therefore be straight forward. The
> libraries should then reside in $MIDASSYS/lib (or %MIDASSYS%\lib under windows).
> 
> To remind users about this new variable, a test has been added to odbedit,
> which shows a warning when starting odbedit and MIDASSYS is not defined.

1. Finally! It's about time to do that! 

2. What will the entire structure tree look like?

Here's my suggestion
MIDASSYS=/opt/midas-1.9.4 (for example)   


so the Linux binaries would go to 
MIDASHOST=i386-pc-linux-gnu
$MIDASSYS/$MIDASHOST/bin
$MIDASSYS/$MIDASHOST/lib

the VxWorks binaries
MIDASHOST=m68k-wrs-vxworks
$MIDASSYS/$MIDASHOST/bin
$MIDASSYS/$MIDASHOST/lib

and the shared stuff would go to 
$MIDASSYS/include
$MIDASSYS/share/drivers
$MIDASSYS/share/examples

The Makefile would need to be adjusted (for make install) but that is not
too complicated

What do you think?

Regards
  Piotr

Version 1.9.4 of midas has been released today. It is mainly a maintenance
update, for all the little things which have been fixed since the last
release, and does not contain major new functionality.