code review 4433047: go/build: new package for building go programs

src/pkg/go/build/cgotest/file.go

+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+A trivial example of wrapping a C library in Go.
+For a more complex example and explanation,
+see ../gmp/gmp.go.
+*/
+
+package stdio
+
+/*
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+char* greeting = "hello, world";
+*/
+import "C"
+import "unsafe"
+
+type File C.FILE
+
+var Stdout = (*File)(C.stdout)
+var Stderr = (*File)(C.stderr)
+
+// Test reference to library symbol.
+// Stdout and stderr are too special to be a reliable test.
+var myerr = C.sys_errlist
+
+func (f *File) WriteString(s string) {
+        p := C.CString(s)
+        C.fputs(p, (*C.FILE)(f))
+        C.free(unsafe.Pointer(p))
+        f.Flush()
+}
+
+func (f *File) Flush() {
+        C.fflush((*C.FILE)(f))
+}
+
+var Greeting = C.GoString(C.greeting)