June 2018 Update

Task/Call-a-function-in-a-shared-library/Kotlin/call-a-function-in-a-shared-library-1.kotlin

@@ -0,0 +1,8 @@
+#include <stdio.h>
+/* gcc -shared -fPIC -nostartfiles fakeimglib.c -o fakeimglib.so */
+int openimage(const char *s)
+{
+    static int handle = 100;
+    fprintf(stderr, "opening %s\n", s);
+    return handle++;
+}

Task/Call-a-function-in-a-shared-library/Kotlin/call-a-function-in-a-shared-library-2.kotlin

@@ -0,0 +1,34 @@
+// Kotlin Native version 0.5
+
+import kotlinx.cinterop.*
+import platform.posix.*
+import platform.linux.*
+
+typealias Func = (String)-> Int
+
+var handle = 0
+
+fun myOpenImage(s: String): Int {
+    fprintf(stderr, "internal openImage opens %s...\n", s)
+    return handle++
+}
+
+fun main(args: Array<String>) {
+    var imgHandle: Int
+    val imglib = dlopen("./fakeimglib.so", RTLD_LAZY)
+    if (imglib != null) {
+        val fp = dlsym(imglib, "openimage")
+        if (fp != null) {
+            val extOpenImage: CPointer<CFunction<Func>> = fp.reinterpret()
+            imgHandle = extOpenImage("fake.img")
+        }
+        else {
+            imgHandle = myOpenImage("fake.img")
+        }
+        dlclose(imglib)
+    }
+    else {
+        imgHandle = myOpenImage("fake.img")
+    }
+    println("opened with handle $imgHandle")
+}

Task/Call-a-function-in-a-shared-library/Perl-6/call-a-function-in-a-shared-library.pl6

@@ -2,8 +2,8 @@ use NativeCall;
 
 constant libX11 = '/usr/lib/x86_64-linux-gnu/libX11.so.6';
 
-sub XOpenDisplay(Str $s --> Int) is native(libX11) {*}
-sub XCloseDisplay(Int $i --> Int) is native(libX11) {*}
+sub XOpenDisplay(Str $s --> int32) is native(libX11) {*}
+sub XCloseDisplay(int32 $i --> int32) is native(libX11) {*}
 
 if try my $d = XOpenDisplay ":0.0" {
     say "ID = $d";

Task/Call-a-function-in-a-shared-library/Python/call-a-function-in-a-shared-library-2.py

@@ -0,0 +1,7 @@
+>>> import ctypes
+>>> # libc = ctypes.cdll.msvcrt # Windows
+>>> # libc = ctypes.CDLL('libc.dylib') # Mac
+>>> libc = ctypes.CDLL('libc.so') # Linux and most other *nix
+>>> libc.printf(b'hi there, %s\n', b'world')
+hi there, world.
+17

Task/Call-a-function-in-a-shared-library/Python/call-a-function-in-a-shared-library-3.py

@@ -0,0 +1,10 @@
+>>> from cffi import FFI
+>>> ffi = FFI()
+>>> ffi.cdef("""
+...     int printf(const char *format, ...);   // copy-pasted from the man page
+... """)
+>>> C = ffi.dlopen(None)                     # loads the entire C namespace
+>>> arg = ffi.new("char[]", b"world")         # equivalent to C code: char arg[] = "world";
+>>> C.printf(b"hi there, %s.\n", arg)         # call printf
+hi there, world.
+17