hyperkang/cffi_mini_demo

A mini demo for cffi

Python

A mini demo for cffi - API level, out-of-line

Demo environment

Ubuntu 14.04.4 LTS
GCC 4.8.2
CPython 2.7.6(with cffi 1.5.2), pypy 5.0.1 (with built-in cffi)

Demo steps:

1. Create a C static lib

Implement a simple function as: int mysum(int a, int b) in ./clib/mysum.c

Complie mysum.c into static lib libmysum.a

cd clib
gcc -c mysum.c
ar -crv libmysum.a mysum.o

Write a testing program in C to link with libmysum.a
- Build testing executable from clib/test_mysum.c
```
gcc ./test_mysum.c -lmysum -L./
```
- Run it (You should see 1+2=3 printed)
```
./a.out
```

2. Run cffi build script to generate python extension

With pypy
```
cd ..
[path]/pypy ./mysum_build.py
```
File _mysum.pypy-41.so should be generated at current directory which can be imported by python code;
With CPython
```
cd ..
[path]/python ./mysum_build.py
```
File _mysum.so should be generated at current directory which can be imported by python code;

3. Test generated extension

With pypy
```
[path]/pypy ./test_mysum.py
```
With CPython
```
[path]/python ./test_mysum.py
```

You should get 1+2=3 printed.