Launching a Script on the Linux Platform

[Wildman]

On Tue, 12 Nov 2019 18:39:38 +0000, Rhodri James wrote:

> On 12/11/2019 18:25, Rob Gaddi wrote:
>> On 11/12/19 10:06 AM, Wildman wrote:
>>> What is the best approach for launching a Python GUI program
>>> on a Linux platform.  The program will be distributed in .deb
>>> format.  So the .deb will contain a menu file as well as a
>>> .desktop file.  The post install script will update the system
>>> menu.
>>>
>>> My question is how should the program be executed?  Here are
>>> two choices for the "command=" entry in the menu file...
>>>
>>> command="/path/to/program.py"
>>>
>>> In this case the hash-bang would have to be included in the
>>> program script... #!/usr/bin/env python3
>>>
>>> The other choice is this...
>>>
>>> command="python3 /path/to/program.py"
>>>
>>> (Of course, the Exec command in the .desktop file should match.)
>>>
>>> Is one method better than the other or does it acutally matter?
>>>
>> 
>> I will note that without the shebang (and setting the execute bit), the 
>> program is only executable from the GUI menu, not the command prompt.  I 
>> personally start even GUI programs far more often from a prompt.
>> 
>> To follow Linux conventions you'd put the shebang, make the file 
>> executable, and put the executable somewhere on the PATH.  I'd stick to 
>> those conventions barring a particular reason not to.
> 
> Wildman is talking about launching his program from a menu, so putting 
> it on the PATH is unnecessary.  It may even be a bad idea, depending on 
> exactly what he's done :-)

Yes, that is correct.  My program would be installed using
a deb package manager such as apt and an entry placed in the
desktop menu to launch the program.

Thank you for the reply Rob.

> As to the original question, there shouldn't really be much of a 
> difference.  The original idea of the shebang line invoking env, as far 
> I recall, was that you'd get the "proper" system python3 wherever it had 
> been put rather than something random and possibly malicious.  I guess 
> that means to go for your first option.

Shebang!  Yea, that is the correct term.  All I could think
of was hashbang.  I knew that wasn't quite right.

Yes, I prefer to envoke env in the shebang line instead of
depending on the path.  Paths can change especially in a
multi-user system but env will always know where to find
the executable.

Thank you for your input.  Shebang is the logical answer
with all else being equal.

-- 
<Wildman> GNU/Linux user #557453
"Setting a good example is a far better way
to spread ideals than through force of arms."
  -Ron Paul