[[Property:title|CECIL - Eiffel to C]]
[[Property:weight|1]]
[[Property:uuid|3d1df3fe-2ac8-1ba3-c846-8329ea8a3772]]
==array==

This example shows how to create a C array from an existing Eiffel array. 

After you have done the appropriate steps to compile the example, you will get a `cecil.exe` on windows, or `cecil` on Unix. 

Launch the program and you will be prompted for 10 integers that will be inserted in an Eiffel array, it will then initialize the C array and display it. 

A typical output will be:
<code>
$ ./cecil
This example create n array on the Eiffel side and print it on the C side
Enter 10 integers:
1
2
3
4
5
6
7
8
9
10

Displaying from C
@1 = 1
@2 = 2
@3 = 3
@4 = 4
@5 = 5
@6 = 6
@7 = 7
@8 = 8
@9 = 9
@10 = 10
</code>

==object==
This example shows the Eiffel memory management and all issues when passing an Eiffel object reference to C. In the example, you can edit the file `root_class.e` to modify the example: 
<code>
--give_to_c (o1)
give_to_c_by_pointer ($o1) -- Choose the way you pass it
</code>
When you choose the first possibility (commented by default), give_to_c will use the CECIL API eif_adopt to keep a reference on the Eiffel object. When you choose the second possibility, give_to_c_by_pointer will use the CECIL API eif_protect to keep a reference on the Eiffel object. Until forget_from_c is called from the C side, the object o1 will not be collected since we have protected it through the call to give_to_c or give_to_c_by_pointer. At the end after the object o1 is collected, we try to perform an operation on it which will fail with a call on void target exception. A typical output will be: 
<code>
$ cecil
Creating o1
Object string is o1
Give it to C
Losing reference to initial o1 from Eiffel
Collecting...
Display new o1:
Object string is o2
Display o1 given to C:
Object string is o1
Losing reference from C
Losing reference from Eiffel
Collecting...
An Eiffel object of type OBJECT is collected
Old o1 forgot from both C and Eiffel:
Raise a Void exception..

cecil: system execution failed.
Following is the set of recorded exceptions:
-------------------------------------------------------------------------------
Class / Object Routine Nature of exception Effect
-------------------------------------------------------------------------------
ROOT_CLASS make @26 display:
<30068030> Feature call on void target. Fail
-------------------------------------------------------------------------------
ROOT_CLASS make @26
<30068030> Routine failure. Fail
-------------------------------------------------------------------------------
ROOT_CLASS root's creation
<30068030> Routine failure. Exit
-------------------------------------------------------------------------------
An Eiffel object of type OBJECT is collected
</code>

==string==
This example shows how to create a C string from an existing Eiffel string. After you have done the appropriate steps to compile the example, you will get a `cecil.exe` on windows, or `cecil` on Unix. Launch the program and you will be prompted for a string from Eiffel and a C string will be created and display. A typical output will be: 
<code>
$ cecil
Enter a string to convert into a C string:
Hello World!

Here is the C string:
Hello World!
</code>