pathdef, savepath, ocaverc and Matlab

[Ben Abbott]

On Jan 4, 2008, at 1:52 AM, Shai Ayal wrote:

> On Jan 3, 2008 12:00 PM, Ben Abbott <bpabbott at mac.com> wrote:
>>
>>
>> On Jan 3, 2008, at 5:37 PM, Ben Abbott wrote:
>>
>>>
>>> On Dec 31, 2007, at 12:30 PM, Ben Abbott wrote:
>>>
>>>>
>>>> On Dec 31, 2007, at 1:12 AM, Ben Abbott wrote:
>>>>
>>>>>
>>>>> On Dec 31, 2007, at 12:49 AM, John W. Eaton wrote:
>>>>>
>>>>>> The savepath function only exists for compatibility with  
>>>>>> Matlab, so
>>>>>> whatever it does should be compatible.
>>>>>>
>>>>>> jwe
>>>>>
>>>>> Good point.
>>>>>
>>>>
>>>> I've spent some time looking over the differences between Matlab
>>>> and Octave regarding path related functions. I've enumerated what I
>>>> found below.
>>>>
>>>> (1) pathdef: In Octave, pathdef() load's the virgin default path.
>>>> In Matlab pathdef.m is a script created by savepath.m, and
>>>> pathdef.m is used to setup Matlab's path each time Matlab is run.
>>>>
>>>> (2) savepath: In Octave, savepath.m saves to current working path
>>>> to ~/.octaverc. In Matlab, it saves the current working path to
>>>> pathdef.m. On my Mac, Matlab doesn't require admin access to
>>>> execute savepath.m ... Can someone tell us if it does on Linux?
>>>>
>>>> (3) restoredefaultpath: In Matlab this allows a user to restore the
>>>> working path to its virgin form. It only impacts the current
>>>> session. In Octave, this may be done by path (pathdef);
>>>>
>>>> (4) matlabroot: In Matlab this returns the path to the root of
>>>> Matlab's installation directory. The Octave equivalent is
>>>> OCTAVE_HOME.
>>>>
>>>> (5) matlabrc: In Matlab matlabrc.m is supposed to have admin access
>>>> (?) and is run each time Matlab is started. It is located in
>>>> <matlabroot>/toolbox/local. The Octave equivalent [of startup] is
>>>> octaverc located in octave-home/share/octave/version/m/startup.
>>>>
>>>> (6) startup: In Matlab startup.m is run (if it exists in the path)
>>>> each time Matlab is started, but only after matlabrc.m. The Octave
>>>> equilvalent is ~/.octaverc.
>>>>
>>>> (7) finish: In Matlab finish.m is run upon a clean exit. From what
>>>> I can tell there is no Octave equivalent.
>>>>
>>>> There are many differences. Some will require changes to c-code
>>>> while the majority require changes to m-files.
>>>>
>>>> I'm up to the task of handling the m-files but will need someone to
>>>> take on the c part.
>>>>
>>>> If it is desirable and appropriate to reconcile these differences,
>>>> I can put together an approach that will allow for incremental
>>>> changes that ensures a functional Octave.
>>>>
>>>> I'll get started on the sequence of events needed. In the meantime,
>>>> I'm eager for feedback so that I'm not wasting effort and/or time.
>>>>
>>>> Ben
>>>
>>> I thought I'd rename the thread, as we've branched into a new
>>> direction.
>>>
>>> Regarding a possible sequence of events to resolve these differences
>>> between Octave and Matlab, I'd like to propose the following.
>>>
>>> (1) Rename the built-in function "pathdef" with to "defaultpath".
>>>
>>> (2) Introduce ".../scripts/path/restoredefaultpath.m", which is
>>> essentially "path (defaultpath);"
>>>
>>> (3) Introduce a new script, named ".../scripts/path/pathdef.m",
>>> which returns the path which an octave session begins with, prior to
>>> running "~/.octaverc".
>>>
>>> (4) The purpose of "savepath" can be left as it is, but might be
>>> modified to save the path to "octave-home/share/octave/version/m/
>>> startup/octavrc" when run with admin privilege. In either event, the
>>> script should warn the user of which file is modified, when a file
>>> is not explicitly specified.
>>>
>>> (5) Add script "matlabroot.m" to ".../scripts/path/matlabroot.m" ...
>>> perhaps an "octaveroot.m" also/instead?
>>>
>>> (6) If it exists in the path, run script "finish.m" upon exiting.
>>>
>>> As I have no experience in c/c++ programming, it is likely a bad
>>> idea for me to take on (1) or (6), but I'm willing to give (1) a
>>> try ... However, if someone is up to posting a patch for (1), I'll
>>> incorporate it into my local build and take on the rest.
>>>
>>> Ben
>>
>> I should have taken a look before send that out. The first item looks
>> very simple.
>
> also the last item -- octave has an atexit function
>
> Shai

Thanks Shai.

Can you or another tell me how I can get to the list of registered  
functions?

While it apprears to me that this should be done in c++, I'm not a c/c+ 
+ programmer, and so I'm hoping to do this by adding a few lines to  
".../startup/octaverc".

For that to be viable, I need to have access to  
"octave_atexit_functions". Is this available? Shall a build-in  
function be added to make it so, or should something else be done?

Ben