text: // Copyright 2013 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.
  
  // +build darwin dragonfly freebsd linux netbsd openbsd solaris
  
  package unix_test
  
  import (
  	"fmt"
  	"testing"
  
  	"golang.org/x/sys/unix"
  )
  
  func testSetGetenv(t *testing.T, key, value string) {
  	err := unix.Setenv(key, value)
  	if err != nil {
  		t.Fatalf("Setenv failed to set %q: %v", value, err)
  	}
  	newvalue, found := unix.Getenv(key)
  	if !found {
  		t.Fatalf("Getenv failed to find %v variable (want value %q)", key, value)
  	}
  	if newvalue != value {
  		t.Fatalf("Getenv(%v) = %q; want %q", key, newvalue, value)
  	}
  }
  
  func TestEnv(t *testing.T) {
  	testSetGetenv(t, "TESTENV", "AVALUE")
  	// make sure TESTENV gets set to "", not deleted
  	testSetGetenv(t, "TESTENV", "")
  }
  
  func TestItoa(t *testing.T) {
  	// Make most negative integer: 0x8000...
  	i := 1
  	for i<<1 != 0 {
  		i <<= 1
  	}
  	if i >= 0 {
  		t.Fatal("bad math")
  	}
  	s := unix.Itoa(i)
  	f := fmt.Sprint(i)
  	if s != f {
  		t.Fatalf("itoa(%d) = %s, want %s", i, s, f)
  	}
  }
  