2016 Update

Task/Call-a-foreign-language-function/00DESCRIPTION

@@ -1,11 +1,16 @@
+;Task:
 Show how a [[Foreign function interface|foreign language function]] can be called from the language.
 
+
 As an example, consider calling functions defined in the [[C]] language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to [[C]]'s <code>strdup</code>. The content can be copied if necessary. Get the result from <code>strdup</code> and print it using language means. Do not forget to free the result of <code>strdup</code> (allocated in the heap).
 
-Notes:
+
+;Notes:
 * It is not mandated if the [[C]] run-time library is to be loaded statically or dynamically. You are free to use either way.
 * [[C++]] and [[C]] solutions can take some other language to communicate with.
 * It is ''not'' mandatory to use <code>strdup</code>, especially if the foreign function interface being demonstrated makes that uninformative.
 
-See also:
-* [[Use another language to call a function]]
+
+;See also:
+* &nbsp; [[Use another language to call a function]]
+<br><br>

Task/Call-a-foreign-language-function/COBOL/call-a-foreign-language-function.cobol

@@ -0,0 +1,27 @@
+       identification division.
+       program-id. foreign.
+
+       data division.
+       working-storage section.
+       01 hello.
+          05 value z"Hello, world".
+       01 duplicate    usage pointer.
+       01 buffer       pic x(16) based.
+       01 storage      pic x(16).
+
+       procedure division.
+       call "strdup" using hello returning duplicate
+           on exception
+               display "error calling strdup" upon syserr
+       end-call
+       if duplicate equal null then
+           display "strdup returned null" upon syserr
+       else
+           set address of buffer to duplicate
+           string buffer delimited by low-value into storage
+           display function trim(storage)
+           call "free" using by value duplicate
+               on exception
+                   display "error calling free" upon syserr
+       end-if
+       goback.

Task/Call-a-foreign-language-function/Fortran/call-a-foreign-language-function.f

@@ -0,0 +1,45 @@
+module c_api
+    use iso_c_binding
+    implicit none
+
+    interface
+        function strdup(ptr) bind(C)
+            import c_ptr
+            type(c_ptr), value :: ptr
+            type(c_ptr) :: strdup
+        end function
+    end interface
+
+    interface
+        subroutine free(ptr) bind(C)
+            import c_ptr
+            type(c_ptr), value :: ptr
+        end subroutine
+    end interface
+
+    interface
+        function puts(ptr) bind(C)
+            import c_ptr, c_int
+            type(c_ptr), value :: ptr
+            integer(c_int) :: puts
+        end function
+    end interface
+end module
+
+program c_example
+    use c_api
+    implicit none
+
+    character(20), target :: str = "Hello, World!" // c_null_char
+    type(c_ptr) :: ptr
+    integer(c_int) :: res
+
+    ptr = strdup(c_loc(str))
+
+    res = puts(c_loc(str))
+    res = puts(ptr)
+
+    print *, transfer(c_loc(str), 0_c_intptr_t), &
+             transfer(ptr, 0_c_intptr_t)
+    call free(ptr)
+end program

Task/Call-a-foreign-language-function/Perl-6/call-a-foreign-language-function.pl6

@@ -1,8 +1,8 @@
 use NativeCall;
 
 sub strdup(Str $s --> OpaquePointer) is native {*}
-sub puts(OpaquePointer $p --> int) is native {*}
-sub free(OpaquePointer $p --> int) is native {*}
+sub puts(OpaquePointer $p --> int32) is native {*}
+sub free(OpaquePointer $p --> int32) is native {*}
 
 my $p = strdup("Success!");
 say 'puts returns ', puts($p);

Task/Call-a-foreign-language-function/Rust/call-a-foreign-language-function.rust

@@ -0,0 +1,13 @@
+extern crate libc;
+
+//c function that returns the sum of two integers
+extern {
+    fn add_input(in1: libc::c_int, in2: libc::c_int) -> libc::c_int;
+}
+
+fn main() {
+    let (in1, in2) = (5, 4);
+    let output = unsafe {
+        add_input(in1, in2) };
+    assert!( (output == (in1 + in2) ),"Error in sum calculation") ;
+}