Hi William, hi Nathann, On 29 Jun., 11:43, William Stein <wst...@gmail.com> wrote: > > I have a C program without a makefile which is meant to be used from > > the command line, and I would like to interface it with SAGE. I have > > been told this should be done through libraries, and I do not have the > > slightest idea of how it works in Cython. I just read those two > > pages : > > >http://docs.sun.com/source/819-3690/Building.Libs.html > >http://www.faqs.org/docs/Linux-HOWTO/Program-Library-HOWTO.html > > > They explain well enough how to build libraries with gcc, but I do not > > know how to access their functions with Cython. ... > > Can you carefully try the examples and read the code here > > http://www.faqs.org/docs/Linux-HOWTO/Program-Library-HOWTO.html#MORE-... >
I understood that Nathann knows how to build libraries with gcc, but that he needs help on using them in Cython. I think http://docs.cython.org/docs/external_C_code.html might help. In a nutshell: You need to declare the C-types/functions/... in your Cython program (this can be done in a .pxd-file, which is analogous to a header file in C). The above page will tell you the differences in syntax. I try a brief example, hoping that I do not do too many mistakes. Let bar.h be long foo(char*); and let the function foo be defined somewhere, resulting in a static library bar.a. Your Cython code (say, wrapbar.pyx) must then do something like this: cdef extern from "bar.h": long foo(char*) def test(s): if isinstance(s, basestring): return foo(s) raise TypeError Running "sage -cython wrapbar.pyx" results in a C-file for your Cython file. Then, you compile it, link against bar.a, and produce a shared library wrapbar.so. Then, in sage, you can do sage: from wrapbar import test and use the function. If I am not mistaken, the conversion from a python string to char* is automatically done. Best regards, Simon --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
