System operating detection

System operating detection

[Andrea Crotti]

Is there a way to make this ugly thing:

--8<---------------cut here---------------start------------->8---
  (defconst sysop
    (cond
     ((string-match "linux" system-configuration) "linux")
     ((string-match "apple" system-configuration) "mac")
     ((string-match "win" system-configuration) "win")
     (t "other")))
  
  (defconst linux (string= "linux" sysop))
  (defconst mac (string= "mac" sysop))
  (defconst win (string= "win" sysop))
  (defconst other (string= "other" sysop))
--8<---------------cut here---------------end--------------->8---

looking better?
I would like to have all the constants defined (to nil or t) but
avoiding this ugly repetition.
One (small) problem is that without the "cond" also "darwin" matches
"win", so I get a wrong constant...

Re: System operating detection

[Richard Riley]

Andrea Crotti <andrea.crotti.0@gmail.com> writes:

> Is there a way to make this ugly thing:
>
>
>
>
> --8<---------------cut here---------------start------------->8---
>   (defconst sysop
>     (cond
>      ((string-match "linux" system-configuration) "linux")
>      ((string-match "apple" system-configuration) "mac")
>      ((string-match "win" system-configuration) "win")
>      (t "other")))
>   
>   (defconst linux (string= "linux" sysop))
>   (defconst mac (string= "mac" sysop))
>   (defconst win (string= "win" sysop))
>   (defconst other (string= "other" sysop))
> --8<---------------cut here---------------end--------------->8---
>
>
>
> looking better?
> I would like to have all the constants defined (to nil or t) but
> avoiding this ugly repetition.
> One (small) problem is that without the "cond" also "darwin" matches
> "win", so I get a wrong constant...


I think you need to show your usage patterns for the variables you have
defined for a better answer. How are you using the results?

That said, maybe just define sysop and then load-library a filename stub
concat'ed with the sysop along the lines of

(load-library (concat "os-specific-" sysop))

is a better approach? And then os-specific-win etc all contain their OS
specific details.

Re: System operating detection

[Andrea Crotti]

Richard Riley <rileyrg@gmail.com> writes:

>
> I think you need to show your usage patterns for the variables you have
> defined for a better answer. How are you using the results?
>
> That said, maybe just define sysop and then load-library a filename stub
> concat'ed with the sysop along the lines of
>
> (load-library (concat "os-specific-" sysop))
>
> is a better approach? And then os-specific-win etc all contain their OS
> specific details.


Well actually I only have some
--8<---------------cut here---------------start------------->8---
(when mac
      (do something))

(when linux
      (do something else))
--8<---------------cut here---------------end--------------->8---

A library with the os-specific stuff might be better, but now I have
everything in the org-file divided by "chapter" (windows, buffers,
frames etc). Doing "system" libraries like that would break a little bit
this model.

Re: System operating detection

[Thierry Volpiatto]

Andrea Crotti <andrea.crotti.0@gmail.com> writes:

> Is there a way to make this ugly thing:
>
>   (defconst sysop
>     (cond
>      ((string-match "linux" system-configuration) "linux")
>      ((string-match "apple" system-configuration) "mac")
>      ((string-match "win" system-configuration) "win")
>      (t "other")))
>   
>   (defconst linux (string= "linux" sysop))
>   (defconst mac (string= "mac" sysop))
>   (defconst win (string= "win" sysop))
>   (defconst other (string= "other" sysop))
>
> looking better?
> I would like to have all the constants defined (to nil or t) but
> avoiding this ugly repetition.
> One (small) problem is that without the "cond" also "darwin" matches
> "win", so I get a wrong constant...

Use case:

,----
| (case system-type
|   (gnu/linux "Linux")
|   (window-nt "windows")
|   (darwin    "mac")
|   (t         "other")
`----



>
>

-- 
Thierry Volpiatto
Get my Gnupg key:
gpg --keyserver pgp.mit.edu --recv-keys 59F29997 

Re: System operating detection

[Andrea Crotti]

Thierry Volpiatto <thierry.volpiatto@gmail.com> writes:

> Andrea Crotti <andrea.crotti.0@gmail.com> writes:
>
> Use case:
>
> ,----
> | (case system-type
> |   (gnu/linux "Linux")
> |   (window-nt "windows")
> |   (darwin    "mac")
> |   (t         "other")
> `----
>
>
>
>>
>>

Ah great I didn't know this, so now is
--8<---------------cut here---------------start------------->8---
  (defconst linux nil)
  (defconst mac nil)
  (defconst win nil)
  (defconst other nil)
  
  (case system-type
    (gnu/linux (setq linux t))
    (window-nt (setq mac t))
    (darwin    (setq win t))
    (t         (setq other t)))
--8<---------------cut here---------------end--------------->8---

But maybe could be even better, what if I create the symbol only if
really needed?

Then I could do
--8<---------------cut here---------------start------------->8---
(if (boundp linux)...
--8<---------------cut here---------------end--------------->8---
which probably becomes even longer.
Isn't there a way to automatically define functions or variables?

Re: System operating detection

[Pascal J. Bourguignon]

Andrea Crotti <andrea.crotti.0@gmail.com> writes:

> Thierry Volpiatto <thierry.volpiatto@gmail.com> writes:
>
>> Andrea Crotti <andrea.crotti.0@gmail.com> writes:
>>
>> Use case:
>>
>> ,----
>> | (case system-type
>> |   (gnu/linux "Linux")
>> |   (window-nt "windows")
>> |   (darwin    "mac")
>> |   (t         "other")
>> `----
>>
>>
>>
>>>
>>>
>
> Ah great I didn't know this, so now is
> --8<---------------cut here---------------start------------->8---
>   (defconst linux nil)
>   (defconst mac nil)
>   (defconst win nil)
>   (defconst other nil)
>   
>   (case system-type
>     (gnu/linux (setq linux t))
>     (window-nt (setq mac t))
>     (darwin    (setq win t))
>     (t         (setq other t)))
> --8<---------------cut here---------------end--------------->8---
>
> But maybe could be even better, what if I create the symbol only if
> really needed?
>
> Then I could do
> --8<---------------cut here---------------start------------->8---
> (if (boundp linux)...
> --8<---------------cut here---------------end--------------->8---
> which probably becomes even longer.
> Isn't there a way to automatically define functions or variables?

What if you write simply:

    (when (eq system-type 'gnu/linux) 
       ...)
?

or, if you have several cases:

   (case system-type
     ((gnu/linux)  (do-something-on-linux))
     ((mac)        (do-something-on-mac))
     (otherwise    (do-something-standard)))

?

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

Re: System operating detection

[Oleksandr Gavenko]

On 2010-08-11 12:06, Andrea Crotti wrote:
> Is there a way to make this ugly thing:
>
> --8<---------------cut here---------------start------------->8---
>    (defconst sysop
>      (cond
>       ((string-match "linux" system-configuration) "linux")
>       ((string-match "apple" system-configuration) "mac")
>       ((string-match "win" system-configuration) "win")
>       (t "other")))
>
>    (defconst linux (string= "linux" sysop))
>    (defconst mac (string= "mac" sysop))
>    (defconst win (string= "win" sysop))
>    (defconst other (string= "other" sysop))
> --8<---------------cut here---------------end--------------->8---
>
> looking better?
> I would like to have all the constants defined (to nil or t) but
> avoiding this ugly repetition.
> One (small) problem is that without the "cond" also "darwin" matches
> "win", so I get a wrong constant...
>
I wrote blog article about useful checks in .emacs:

http://brain-break.blogspot.com/2010/08/determining-running-environment-and.html

---
Best regards!

Re: System operating detection

[TheFlyingDutchman]

On Aug 11, 2:06 am, Andrea Crotti <andrea.crott...@gmail.com> wrote:
> Is there a way to make this ugly thing:
>
> --8<---------------cut here---------------start------------->8---
>   (defconst sysop
>     (cond
>      ((string-match "linux" system-configuration) "linux")
>      ((string-match "apple" system-configuration) "mac")
>      ((string-match "win" system-configuration) "win")

I am using Windows 7 Home Premium and (from Help->About Emacs) "GNU
Emacs 23.2.1 (i386-mingw-nt6.1.7600)  of 2010-05-08 on G41R2F1", and
the value for system-configuration is "i386-mingw-nt6.1.7600". I guess
they have changed the format of system-configuration for Windows?? For
system-type I have "windows-nt".  Maybe sytem-type is a better
variable to check??


>      (t "other")))
>
>   (defconst linux (string= "linux" sysop))
>   (defconst mac (string= "mac" sysop))
>   (defconst win (string= "win" sysop))
>   (defconst other (string= "other" sysop))
> --8<---------------cut here---------------end--------------->8---
>
> looking better?
> I would like to have all the constants defined (to nil or t) but
> avoiding this ugly repetition.
> One (small) problem is that without the "cond" also "darwin" matches
> "win", so I get a wrong constant...