On 10/17/07, Pierre <[EMAIL PROTECTED]> wrote:
> thanks for your message! i'm confused with one thing:
>
> > > -- and then for standalone scripts i use
> > > #!/usr/bin/env sage
>
> > Yep, that should work fine.  That's for a script that
> > is written using Sage.  You can also use
> >
> > #!/usr/bin/env sage  -python
> >
> > for a script that uses the Python included with Sage.
>
> i'm not 100% sure if i understand the difference between the two. My
> guess is: 'sage -python' uses the version of python coming with sage,
> and that's all; whereas 'sage' does in fact a bit more, in that it
> sets up the sage library somehow. Is that it ?

Actually, there really isn't much of a difference.

The best thing to do is just use

 #!/usr/bin/env sage

since on some systems having a space in the command name given
to /usr/bin/env doesn't work.

Really, the main difference is just that putting "sage" works
and putting "sage -python" doesn't for a generic shell script.

HOWEVER, if you make a script that has a filename that ends in .sage,
then make the first line
  #!/usr/bin/env sage
then the code inside the script is evaluated as if you typed
it on the Sage command line, so you do *not* have to type
   from sage.all import *
and the input is preparsed.

I.e.,

[EMAIL PROTECTED]:~/tmp$ more foo.sage
#!/usr/bin/env sage
print 2^3
[EMAIL PROTECTED]:~/tmp$ ./foo.sage
8

BUT,

[EMAIL PROTECTED]:~/tmp$ more foo    # file doesn't end in .py
#!/usr/bin/env sage
print 2^3
[EMAIL PROTECTED]:~/tmp$ ./foo
1          # <--------------------------- not 8 -- no preparsing


Clearly the tutorial needs to be improved to reflect this.

> (btw while i'm at it, thanks a lot for your work on sage, it's great.
> At the moment i'm writing some C++ programs and i'm using sage to help
> them get information from GAP and run in the right order accordingly,
> it's brilliantly convenient)

I'm glad you're finding Sage useful.  Thanks for asking questions.

 -- William

--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-forum
URLs: http://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/
-~----------~----~----~----~------~----~------~--~---

Reply via email to