Added capacity to slice creation

Make sure we're not vulnerable to CVE-2019-11253.
See https://github.com/kubernetes/kubernetes/issues/83253

.gitignore

@@ -21,4 +21,9 @@ _testmain.go
 
 *.exe
 *.test
-*.bench
+*.bench
+
+.vscode
+
+# exclude dependencies in the `/vendor` folder
+vendor

.travis.yml

@@ -1,9 +1,16 @@
 go_import_path: github.com/spf13/viper
 
 language: go
+
+env:
+  global:
+    - GO111MODULE="on"
+    - GOFLAGS="-mod=readonly"
+
 go:
-  - 1.9.x
-  - 1.10.x
+  - 1.11.x
+  - 1.12.x
+  - 1.13.x
   - tip
 
 os:
@@ -23,5 +30,3 @@ script:
 after_success:
   - go get -u -d github.com/spf13/hugo
   - cd $GOPATH/src/github.com/spf13/hugo && make && ./hugo -s docs && cd -
-
-sudo: false

README.md

@@ -15,6 +15,10 @@ Many Go projects are built using Viper including:
 
 [![Build Status](https://travis-ci.org/spf13/viper.svg)](https://travis-ci.org/spf13/viper) [![Join the chat at https://gitter.im/spf13/viper](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/spf13/viper?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) [![GoDoc](https://godoc.org/github.com/spf13/viper?status.svg)](https://godoc.org/github.com/spf13/viper)
 
+## Install
+```console
+go get -u github.com/spf13/viper
+```
 
 ## What is Viper?
 
@@ -23,7 +27,7 @@ to work within an application, and can handle all types of configuration needs
 and formats. It supports:
 
 * setting defaults
-* reading from JSON, TOML, YAML, HCL, and Java properties config files
+* reading from JSON, TOML, YAML, HCL, envfile and Java properties config files
 * live watching and re-reading of config files (optional)
 * reading from environment variables
 * reading from remote config systems (etcd or Consul), and watching changes
@@ -42,7 +46,7 @@ Viper is here to help with that.
 
 Viper does the following for you:
 
-1. Find, load, and unmarshal a configuration file in JSON, TOML, YAML, HCL, or Java properties formats.
+1. Find, load, and unmarshal a configuration file in JSON, TOML, YAML, HCL, envfile or Java properties formats.
 2. Provide a mechanism to set default values for your different
    configuration options.
 3. Provide a mechanism to set override values for options specified through
@@ -83,7 +87,7 @@ viper.SetDefault("Taxonomies", map[string]string{"tag": "tags", "category": "cat
 ### Reading Config Files
 
 Viper requires minimal configuration so it knows where to look for config files.
-Viper supports JSON, TOML, YAML, HCL, and Java Properties files. Viper can search multiple paths, but
+Viper supports JSON, TOML, YAML, HCL, envfile and Java Properties files. Viper can search multiple paths, but
 currently a single Viper instance only supports a single configuration file.
 Viper does not default to any configuration search paths leaving defaults decision
 to an application.
@@ -103,6 +107,42 @@ if err != nil { // Handle errors reading the config file
 }
 ```
 
+You can handle the specific case where no config file is found like this:
+
+```go
+if err := viper.ReadInConfig(); err != nil {
+    if _, ok := err.(viper.ConfigFileNotFoundError); ok {
+        // Config file not found; ignore error if desired
+    } else {
+        // Config file was found but another error was produced
+    }
+}
+
+// Config file found and successfully parsed
+```
+
+### Writing Config Files
+
+Reading from config files is useful, but at times you want to store all modifications made at run time.
+For that, a bunch of commands are available, each with its own purpose:
+
+* WriteConfig - writes the current viper configuration to the predefined path, if exists. Errors if no predefined path. Will overwrite the current config file, if it exists.
+* SafeWriteConfig - writes the current viper configuration to the predefined path. Errors if no predefined path. Will not overwrite the current config file, if it exists.
+* WriteConfigAs - writes the current viper configuration to the given filepath. Will overwrite the given file, if it exists.
+* SafeWriteConfigAs - writes the current viper configuration to the given filepath. Will not overwrite the given file, if it exists.
+
+As a rule of the thumb, everything marked with safe won't overwrite any file, but just create if not existent, whilst the default behavior is to create or truncate.
+
+A small examples section:
+
+```go
+viper.WriteConfig() // writes current config to predefined path set by 'viper.AddConfigPath()' and 'viper.SetConfigName'
+viper.SafeWriteConfig()
+viper.WriteConfigAs("/path/to/my/.config")
+viper.SafeWriteConfigAs("/path/to/my/.config") // will error since it has already been written
+viper.SafeWriteConfigAs("/path/to/my/.other_config")
+```
+
 ### Watching and re-reading config files
 
 Viper supports the ability to have your application live read a config file while running.
@@ -179,13 +219,14 @@ viper.GetBool("verbose") // true
 ### Working with Environment Variables
 
 Viper has full support for environment variables. This enables 12 factor
-applications out of the box. There are four methods that exist to aid working
+applications out of the box. There are five methods that exist to aid working
 with ENV:
 
  * `AutomaticEnv()`
  * `BindEnv(string...) : error`
  * `SetEnvPrefix(string)`
  * `SetEnvKeyReplacer(string...) *strings.Replacer`
+ * `AllowEmptyEnv(bool)`
 
 _When working with ENV variables, it’s important to recognize that Viper
 treats ENV variables as case sensitive._
@@ -198,9 +239,9 @@ prefix.
 `BindEnv` takes one or two parameters. The first parameter is the key name, the
 second is the name of the environment variable. The name of the environment
 variable is case sensitive. If the ENV variable name is not provided, then
-Viper will automatically assume that the key name matches the ENV variable name,
-but the ENV variable is IN ALL CAPS. When you explicitly provide the ENV
-variable name, it **does not** automatically add the prefix.
+Viper will automatically assume that the ENV variable matches the following format: prefix + "_" + the key name in ALL CAPS. When you explicitly provide the ENV variable name (the second parameter),
+it **does not** automatically add the prefix. For example if the second parameter is "id",
+Viper will look for the ENV variable "ID".
 
 One important thing to recognize when working with ENV variables is that the
 value will be read each time it is accessed. Viper does not fix the value when
@@ -217,6 +258,10 @@ keys to an extent. This is useful if you want to use `-` or something in your
 `Get()` calls, but want your environmental variables to use `_` delimiters. An
 example of using it can be found in `viper_test.go`.
 
+By default empty environment variables are considered unset and will fall back to
+the next configuration source. To treat empty environment variables as set, use
+the `AllowEmptyEnv` method.
+
 #### Env example
 
 ```go
@@ -341,7 +386,7 @@ package:
 
 `import _ "github.com/spf13/viper/remote"`
 
-Viper will read a config string (as JSON, TOML, YAML or HCL) retrieved from a path
+Viper will read a config string (as JSON, TOML, YAML, HCL or envfile) retrieved from a path
 in a Key/Value store such as etcd or Consul.  These values take precedence over
 default values, but are overridden by configuration values retrieved from disk,
 flags, or environment variables.
@@ -373,17 +418,38 @@ how to use Consul.
 
 ### Remote Key/Value Store Example - Unencrypted
 
+#### etcd
 ```go
 viper.AddRemoteProvider("etcd", "http://127.0.0.1:4001","/config/hugo.json")
-viper.SetConfigType("json") // because there is no file extension in a stream of bytes, supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop"
+viper.SetConfigType("json") // because there is no file extension in a stream of bytes, supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop", "env", "dotenv"
 err := viper.ReadRemoteConfig()
 ```
 
+#### Consul
+You need to set a key to Consul key/value storage with JSON value containing your desired config.  
+For example, create a Consul key/value store key `MY_CONSUL_KEY` with value:
+
+```json
+{
+    "port": 8080,
+    "hostname": "myhostname.com"
+}
+```
+
+```go
+viper.AddRemoteProvider("consul", "localhost:8500", "MY_CONSUL_KEY")
+viper.SetConfigType("json") // Need to explicitly set this to json
+err := viper.ReadRemoteConfig()
+
+fmt.Println(viper.Get("port")) // 8080
+fmt.Println(viper.Get("hostname")) // myhostname.com
+```
+
 ### Remote Key/Value Store Example - Encrypted
 
 ```go
 viper.AddSecureRemoteProvider("etcd","http://127.0.0.1:4001","/config/hugo.json","/etc/secrets/mykeyring.gpg")
-viper.SetConfigType("json") // because there is no file extension in a stream of bytes,  supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop"
+viper.SetConfigType("json") // because there is no file extension in a stream of bytes,  supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop", "env", "dotenv"
 err := viper.ReadRemoteConfig()
 ```
 
@@ -394,7 +460,7 @@ err := viper.ReadRemoteConfig()
 var runtime_viper = viper.New()
 
 runtime_viper.AddRemoteProvider("etcd", "http://127.0.0.1:4001", "/config/hugo.yml")
-runtime_viper.SetConfigType("yaml") // because there is no file extension in a stream of bytes, supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop"
+runtime_viper.SetConfigType("yaml") // because there is no file extension in a stream of bytes, supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop", "env", "dotenv"
 
 // read from remote config the first time.
 err := runtime_viper.ReadRemoteConfig()
@@ -430,6 +496,7 @@ The following functions and methods exist:
  * `GetBool(key string) : bool`
  * `GetFloat64(key string) : float64`
  * `GetInt(key string) : int`
+ * `GetIntSlice(key string) : []int`
  * `GetString(key string) : string`
  * `GetStringMap(key string) : map[string]interface{}`
  * `GetStringMapString(key string) : map[string]string`
@@ -585,15 +652,17 @@ type config struct {
 
 var C config
 
-err := Unmarshal(&C)
+err := viper.Unmarshal(&C)
 if err != nil {
 	t.Fatalf("unable to decode into struct, %v", err)
 }
 ```
 
+Viper uses [github.com/mitchellh/mapstructure](https://github.com/mitchellh/mapstructure) under the hood for unmarshaling values which uses `mapstructure` tags by default.
+
 ### Marshalling to string
 
-You may need to marhsal all the settings held in viper into a string rather than write them to a file. 
+You may need to marshal all the settings held in viper into a string rather than write them to a file. 
 You can use your favorite format's marshaller with the config returned by `AllSettings()`.
 
 ```go
@@ -604,11 +673,11 @@ import (
 
 func yamlStringSettings() string {
     c := viper.AllSettings()
-	bs, err := yaml.Marshal(c)
-	if err != nil {
-        t.Fatalf("unable to marshal config to YAML: %v", err)
+    bs, err := yaml.Marshal(c)
+    if err != nil {
+        log.Fatalf("unable to marshal config to YAML: %v", err)
     }
-	return string(bs)
+    return string(bs)
 }
 ```
 

flags.go

@@ -36,7 +36,7 @@ type pflagValue struct {
 	flag *pflag.Flag
 }
 
-// HasChanges returns whether the flag has changes or not.
+// HasChanged returns whether the flag has changes or not.
 func (p pflagValue) HasChanged() bool {
 	return p.flag.Changed
 }

go.mod

@@ -0,0 +1,46 @@
+module github.com/spf13/viper
+
+go 1.12
+
+require (
+	github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6 // indirect
+	github.com/coreos/bbolt v1.3.2 // indirect
+	github.com/coreos/etcd v3.3.10+incompatible // indirect
+	github.com/coreos/go-semver v0.2.0 // indirect
+	github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e // indirect
+	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
+	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
+	github.com/fsnotify/fsnotify v1.4.7
+	github.com/gogo/protobuf v1.2.1 // indirect
+	github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef // indirect
+	github.com/google/btree v1.0.0 // indirect
+	github.com/gorilla/websocket v1.4.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-middleware v1.0.0 // indirect
+	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
+	github.com/grpc-ecosystem/grpc-gateway v1.9.0 // indirect
+	github.com/hashicorp/hcl v1.0.0
+	github.com/jonboulle/clockwork v0.1.0 // indirect
+	github.com/magiconair/properties v1.8.1
+	github.com/mitchellh/mapstructure v1.1.2
+	github.com/pelletier/go-toml v1.2.0
+	github.com/prometheus/client_golang v0.9.3 // indirect
+	github.com/soheilhy/cmux v0.1.4 // indirect
+	github.com/spf13/afero v1.1.2
+	github.com/spf13/cast v1.3.0
+	github.com/spf13/jwalterweatherman v1.0.0
+	github.com/spf13/pflag v1.0.3
+	github.com/stretchr/testify v1.2.2
+	github.com/subosito/gotenv v1.2.0
+	github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5 // indirect
+	github.com/ugorji/go v1.1.4 // indirect
+	github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 // indirect
+	github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77
+	go.etcd.io/bbolt v1.3.2 // indirect
+	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/multierr v1.1.0 // indirect
+	go.uber.org/zap v1.10.0 // indirect
+	golang.org/x/net v0.0.0-20190522155817-f3200d17e092 // indirect
+	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
+	google.golang.org/grpc v1.21.0 // indirect
+	gopkg.in/yaml.v2 v2.2.4
+)

go.sum

@@ -0,0 +1,180 @@
+cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
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+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
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+github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
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remote/remote.go

@@ -77,11 +77,12 @@ func getConfigManager(rp viper.RemoteProvider) (crypt.ConfigManager, error) {
 	var err error
 
 	if rp.SecretKeyring() != "" {
-		kr, err := os.Open(rp.SecretKeyring())
-		defer kr.Close()
+		var kr *os.File
+		kr, err = os.Open(rp.SecretKeyring())
 		if err != nil {
 			return nil, err
 		}
+		defer kr.Close()
 		if rp.Provider() == "etcd" {
 			cm, err = crypt.NewEtcdConfigManager([]string{rp.Endpoint()}, kr)
 		} else {

viper.go

@@ -3,7 +3,7 @@
 // Use of this source code is governed by an MIT-style
 // license that can be found in the LICENSE file.
 
-// Viper is a application configuration system.
+// Viper is an application configuration system.
 // It believes that applications can be configured a variety of ways
 // via flags, ENVIRONMENT variables, configuration files retrieved
 // from the file system, or a remote key/value store.
@@ -30,6 +30,7 @@ import (
 	"path/filepath"
 	"reflect"
 	"strings"
+	"sync"
 	"time"
 
 	yaml "gopkg.in/yaml.v2"
@@ -44,6 +45,7 @@ import (
 	"github.com/spf13/cast"
 	jww "github.com/spf13/jwalterweatherman"
 	"github.com/spf13/pflag"
+	"github.com/subosito/gotenv"
 )
 
 // ConfigMarshalError happens when failing to marshal the configuration.
@@ -179,13 +181,15 @@ type Viper struct {
 	remoteProviders []*defaultRemoteProvider
 
 	// Name of file to look for inside the path
-	configName string
-	configFile string
-	configType string
-	envPrefix  string
+	configName        string
+	configFile        string
+	configType        string
+	configPermissions os.FileMode
+	envPrefix         string
 
 	automaticEnvApplied bool
 	envKeyReplacer      *strings.Replacer
+	allowEmptyEnv       bool
 
 	config         map[string]interface{}
 	override       map[string]interface{}
@@ -208,6 +212,7 @@ func New() *Viper {
 	v := new(Viper)
 	v.keyDelim = "."
 	v.configName = "config"
+	v.configPermissions = os.FileMode(0644)
 	v.fs = afero.NewOsFs()
 	v.config = make(map[string]interface{})
 	v.override = make(map[string]interface{})
@@ -221,12 +226,12 @@ func New() *Viper {
 	return v
 }
 
-// Intended for testing, will reset all to default settings.
+// Reset is intended for testing, will reset all to default settings.
 // In the public interface for the viper package so applications
 // can use it in their testing as well.
 func Reset() {
 	v = New()
-	SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl"}
+	SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "dotenv", "env"}
 	SupportedRemoteProviders = []string{"etcd", "consul"}
 }
 
@@ -265,7 +270,7 @@ type RemoteProvider interface {
 }
 
 // SupportedExts are universally supported extensions.
-var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl"}
+var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "dotenv", "env"}
 
 // SupportedRemoteProviders are universally supported remote providers.
 var SupportedRemoteProviders = []string{"etcd", "consul"}
@@ -276,48 +281,74 @@ func (v *Viper) OnConfigChange(run func(in fsnotify.Event)) {
 }
 
 func WatchConfig() { v.WatchConfig() }
+
 func (v *Viper) WatchConfig() {
+	initWG := sync.WaitGroup{}
+	initWG.Add(1)
 	go func() {
 		watcher, err := fsnotify.NewWatcher()
 		if err != nil {
 			log.Fatal(err)
 		}
 		defer watcher.Close()
-
 		// we have to watch the entire directory to pick up renames/atomic saves in a cross-platform way
 		filename, err := v.getConfigFile()
 		if err != nil {
-			log.Println("error:", err)
+			log.Printf("error: %v\n", err)
+			initWG.Done()
 			return
 		}
 
 		configFile := filepath.Clean(filename)
 		configDir, _ := filepath.Split(configFile)
+		realConfigFile, _ := filepath.EvalSymlinks(filename)
 
-		done := make(chan bool)
+		eventsWG := sync.WaitGroup{}
+		eventsWG.Add(1)
 		go func() {
 			for {
 				select {
-				case event := <-watcher.Events:
-					// we only care about the config file
-					if filepath.Clean(event.Name) == configFile {
-						if event.Op&fsnotify.Write == fsnotify.Write || event.Op&fsnotify.Create == fsnotify.Create {
-							err := v.ReadInConfig()
-							if err != nil {
-								log.Println("error:", err)
-							}
+				case event, ok := <-watcher.Events:
+					if !ok { // 'Events' channel is closed
+						eventsWG.Done()
+						return
+					}
+					currentConfigFile, _ := filepath.EvalSymlinks(filename)
+					// we only care about the config file with the following cases:
+					// 1 - if the config file was modified or created
+					// 2 - if the real path to the config file changed (eg: k8s ConfigMap replacement)
+					const writeOrCreateMask = fsnotify.Write | fsnotify.Create
+					if (filepath.Clean(event.Name) == configFile &&
+						event.Op&writeOrCreateMask != 0) ||
+						(currentConfigFile != "" && currentConfigFile != realConfigFile) {
+						realConfigFile = currentConfigFile
+						err := v.ReadInConfig()
+						if err != nil {
+							log.Printf("error reading config file: %v\n", err)
+						}
+						if v.onConfigChange != nil {
 							v.onConfigChange(event)
 						}
+					} else if filepath.Clean(event.Name) == configFile &&
+						event.Op&fsnotify.Remove&fsnotify.Remove != 0 {
+						eventsWG.Done()
+						return
 					}
-				case err := <-watcher.Errors:
-					log.Println("error:", err)
+
+				case err, ok := <-watcher.Errors:
+					if ok { // 'Errors' channel is not closed
+						log.Printf("watcher error: %v\n", err)
+					}
+					eventsWG.Done()
+					return
 				}
 			}
 		}()
-
 		watcher.Add(configDir)
-		<-done
+		initWG.Done()   // done initializing the watch in this go routine, so the parent routine can move on...
+		eventsWG.Wait() // now, wait for event loop to end in this go-routine...
 	}()
+	initWG.Wait() // make sure that the go routine above fully ended before returning
 }
 
 // SetConfigFile explicitly defines the path, name and extension of the config file.
@@ -347,6 +378,14 @@ func (v *Viper) mergeWithEnvPrefix(in string) string {
 	return strings.ToUpper(in)
 }
 
+// AllowEmptyEnv tells Viper to consider set,
+// but empty environment variables as valid values instead of falling back.
+// For backward compatibility reasons this is false by default.
+func AllowEmptyEnv(allowEmptyEnv bool) { v.AllowEmptyEnv(allowEmptyEnv) }
+func (v *Viper) AllowEmptyEnv(allowEmptyEnv bool) {
+	v.allowEmptyEnv = allowEmptyEnv
+}
+
 // TODO: should getEnv logic be moved into find(). Can generalize the use of
 // rewriting keys many things, Ex: Get('someKey') -> some_key
 // (camel case to snake case for JSON keys perhaps)
@@ -354,11 +393,14 @@ func (v *Viper) mergeWithEnvPrefix(in string) string {
 // getEnv is a wrapper around os.Getenv which replaces characters in the original
 // key. This allows env vars which have different keys than the config object
 // keys.
-func (v *Viper) getEnv(key string) string {
+func (v *Viper) getEnv(key string) (string, bool) {
 	if v.envKeyReplacer != nil {
 		key = v.envKeyReplacer.Replace(key)
 	}
-	return os.Getenv(key)
+
+	val, ok := os.LookupEnv(key)
+
+	return val, ok && (v.allowEmptyEnv || val != "")
 }
 
 // ConfigFileUsed returns the file used to populate the config registry.
@@ -585,10 +627,9 @@ func (v *Viper) isPathShadowedInFlatMap(path []string, mi interface{}) string {
 //       "foo.bar.baz" in a lower-priority map
 func (v *Viper) isPathShadowedInAutoEnv(path []string) string {
 	var parentKey string
-	var val string
 	for i := 1; i < len(path); i++ {
 		parentKey = strings.Join(path[0:i], v.keyDelim)
-		if val = v.getEnv(v.mergeWithEnvPrefix(parentKey)); val != "" {
+		if _, ok := v.getEnv(v.mergeWithEnvPrefix(parentKey)); ok {
 			return parentKey
 		}
 	}
@@ -648,8 +689,16 @@ func (v *Viper) Get(key string) interface{} {
 			return cast.ToBool(val)
 		case string:
 			return cast.ToString(val)
-		case int64, int32, int16, int8, int:
+		case int32, int16, int8, int:
 			return cast.ToInt(val)
+		case uint:
+			return cast.ToUint(val)
+		case uint32:
+			return cast.ToUint32(val)
+		case uint64:
+			return cast.ToUint64(val)
+		case int64:
+			return cast.ToInt64(val)
 		case float64, float32:
 			return cast.ToFloat64(val)
 		case time.Time:
@@ -658,6 +707,8 @@ func (v *Viper) Get(key string) interface{} {
 			return cast.ToDuration(val)
 		case []string:
 			return cast.ToStringSlice(val)
+		case []int:
+			return cast.ToIntSlice(val)
 		}
 	}
 
@@ -711,6 +762,24 @@ func (v *Viper) GetInt64(key string) int64 {
 	return cast.ToInt64(v.Get(key))
 }
 
+// GetUint returns the value associated with the key as an unsigned integer.
+func GetUint(key string) uint { return v.GetUint(key) }
+func (v *Viper) GetUint(key string) uint {
+	return cast.ToUint(v.Get(key))
+}
+
+// GetUint32 returns the value associated with the key as an unsigned integer.
+func GetUint32(key string) uint32 { return v.GetUint32(key) }
+func (v *Viper) GetUint32(key string) uint32 {
+	return cast.ToUint32(v.Get(key))
+}
+
+// GetUint64 returns the value associated with the key as an unsigned integer.
+func GetUint64(key string) uint64 { return v.GetUint64(key) }
+func (v *Viper) GetUint64(key string) uint64 {
+	return cast.ToUint64(v.Get(key))
+}
+
 // GetFloat64 returns the value associated with the key as a float64.
 func GetFloat64(key string) float64 { return v.GetFloat64(key) }
 func (v *Viper) GetFloat64(key string) float64 {
@@ -729,6 +798,12 @@ func (v *Viper) GetDuration(key string) time.Duration {
 	return cast.ToDuration(v.Get(key))
 }
 
+// GetIntSlice returns the value associated with the key as a slice of int values.
+func GetIntSlice(key string) []int { return v.GetIntSlice(key) }
+func (v *Viper) GetIntSlice(key string) []int {
+	return cast.ToIntSlice(v.Get(key))
+}
+
 // GetStringSlice returns the value associated with the key as a slice of strings.
 func GetStringSlice(key string) []string { return v.GetStringSlice(key) }
 func (v *Viper) GetStringSlice(key string) []string {
@@ -772,8 +847,6 @@ func (v *Viper) UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConf
 		return err
 	}
 
-	v.insensitiviseMaps()
-
 	return nil
 }
 
@@ -789,8 +862,6 @@ func (v *Viper) Unmarshal(rawVal interface{}, opts ...DecoderConfigOption) error
 		return err
 	}
 
-	v.insensitiviseMaps()
-
 	return nil
 }
 
@@ -833,8 +904,6 @@ func (v *Viper) UnmarshalExact(rawVal interface{}) error {
 		return err
 	}
 
-	v.insensitiviseMaps()
-
 	return nil
 }
 
@@ -953,6 +1022,11 @@ func (v *Viper) find(lcaseKey string) interface{} {
 			s = strings.TrimSuffix(s, "]")
 			res, _ := readAsCSV(s)
 			return res
+		case "intSlice":
+			s := strings.TrimPrefix(flag.ValueString(), "[")
+			s = strings.TrimSuffix(s, "]")
+			res, _ := readAsCSV(s)
+			return cast.ToIntSlice(res)
 		default:
 			return flag.ValueString()
 		}
@@ -965,7 +1039,7 @@ func (v *Viper) find(lcaseKey string) interface{} {
 	if v.automaticEnvApplied {
 		// even if it hasn't been registered, if automaticEnv is used,
 		// check any Get request
-		if val = v.getEnv(v.mergeWithEnvPrefix(lcaseKey)); val != "" {
+		if val, ok := v.getEnv(v.mergeWithEnvPrefix(lcaseKey)); ok {
 			return val
 		}
 		if nested && v.isPathShadowedInAutoEnv(path) != "" {
@@ -974,7 +1048,7 @@ func (v *Viper) find(lcaseKey string) interface{} {
 	}
 	envkey, exists := v.env[lcaseKey]
 	if exists {
-		if val = v.getEnv(envkey); val != "" {
+		if val, ok := v.getEnv(envkey); ok {
 			return val
 		}
 	}
@@ -1022,6 +1096,11 @@ func (v *Viper) find(lcaseKey string) interface{} {
 			s = strings.TrimSuffix(s, "]")
 			res, _ := readAsCSV(s)
 			return res
+		case "intSlice":
+			s := strings.TrimPrefix(flag.ValueString(), "[")
+			s = strings.TrimSuffix(s, "]")
+			res, _ := readAsCSV(s)
+			return cast.ToIntSlice(res)
 		default:
 			return flag.ValueString()
 		}
@@ -1064,8 +1143,8 @@ func (v *Viper) SetEnvKeyReplacer(r *strings.Replacer) {
 	v.envKeyReplacer = r
 }
 
-// Aliases provide another accessor for the same key.
-// This enables one to change a name without breaking the application
+// RegisterAlias creates an alias that provides another accessor for the same key.
+// This enables one to change a name without breaking the application.
 func RegisterAlias(alias string, key string) { v.RegisterAlias(alias, key) }
 func (v *Viper) RegisterAlias(alias string, key string) {
 	v.registerAlias(alias, strings.ToLower(key))
@@ -1139,7 +1218,7 @@ func (v *Viper) SetDefault(key string, value interface{}) {
 	deepestMap[lastKey] = value
 }
 
-// Set sets the value for the key in the override regiser.
+// Set sets the value for the key in the override register.
 // Set is case-insensitive for a key.
 // Will be used instead of values obtained via
 // flags, config file, ENV, default, or key/value store.
@@ -1220,13 +1299,21 @@ func (v *Viper) ReadConfig(in io.Reader) error {
 // MergeConfig merges a new configuration with an existing config.
 func MergeConfig(in io.Reader) error { return v.MergeConfig(in) }
 func (v *Viper) MergeConfig(in io.Reader) error {
-	if v.config == nil {
-		v.config = make(map[string]interface{})
-	}
 	cfg := make(map[string]interface{})
 	if err := v.unmarshalReader(in, cfg); err != nil {
 		return err
 	}
+	return v.MergeConfigMap(cfg)
+}
+
+// MergeConfigMap merges the configuration from the map given with an existing config.
+// Note that the map given may be modified.
+func MergeConfigMap(cfg map[string]interface{}) error { return v.MergeConfigMap(cfg) }
+func (v *Viper) MergeConfigMap(cfg map[string]interface{}) error {
+	if v.config == nil {
+		v.config = make(map[string]interface{})
+	}
+	insensitiviseMap(cfg)
 	mergeMaps(cfg, v.config, nil)
 	return nil
 }
@@ -1277,21 +1364,21 @@ func (v *Viper) writeConfig(filename string, force bool) error {
 	if v.config == nil {
 		v.config = make(map[string]interface{})
 	}
-	var flags int
-	if force == true {
-		flags = os.O_CREATE | os.O_TRUNC | os.O_WRONLY
-	} else {
-		if _, err := os.Stat(filename); os.IsNotExist(err) {
-			flags = os.O_WRONLY
-		} else {
-			return fmt.Errorf("File: %s exists. Use WriteConfig to overwrite.", filename)
-		}
+	flags := os.O_CREATE | os.O_TRUNC | os.O_WRONLY
+	if !force {
+		flags |= os.O_EXCL
 	}
-	f, err := v.fs.OpenFile(filename, flags, os.FileMode(0644))
+	f, err := v.fs.OpenFile(filename, flags, v.configPermissions)
 	if err != nil {
 		return err
 	}
-	return v.marshalWriter(f, configType)
+	defer f.Close()
+
+	if err := v.marshalWriter(f, configType); err != nil {
+		return err
+	}
+
+	return f.Sync()
 }
 
 // Unmarshal a Reader into a map.
@@ -1315,7 +1402,7 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 		}
 
 	case "hcl":
-		obj, err := hcl.Parse(string(buf.Bytes()))
+		obj, err := hcl.Parse(buf.String())
 		if err != nil {
 			return ConfigParseError{err}
 		}
@@ -1333,6 +1420,15 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 			c[k] = v
 		}
 
+	case "dotenv", "env":
+		env, err := gotenv.StrictParse(buf)
+		if err != nil {
+			return ConfigParseError{err}
+		}
+		for k, v := range env {
+			c[k] = v
+		}
+
 	case "properties", "props", "prop":
 		v.properties = properties.NewProperties()
 		var err error
@@ -1373,6 +1469,9 @@ func (v *Viper) marshalWriter(f afero.File, configType string) error {
 
 	case "hcl":
 		b, err := json.Marshal(c)
+		if err != nil {
+			return ConfigMarshalError{err}
+		}
 		ast, err := hcl.Parse(string(b))
 		if err != nil {
 			return ConfigMarshalError{err}
@@ -1398,6 +1497,18 @@ func (v *Viper) marshalWriter(f afero.File, configType string) error {
 			return ConfigMarshalError{err}
 		}
 
+	case "dotenv", "env":
+		lines := []string{}
+		for _, key := range v.AllKeys() {
+			envName := strings.ToUpper(strings.Replace(key, ".", "_", -1))
+			val := v.Get(key)
+			lines = append(lines, fmt.Sprintf("%v=%v", envName, val))
+		}
+		s := strings.Join(lines, "\n")
+		if _, err := f.WriteString(s); err != nil {
+			return ConfigMarshalError{err}
+		}
+
 	case "toml":
 		t, err := toml.TreeFromMap(c)
 		if err != nil {
@@ -1532,13 +1643,6 @@ func (v *Viper) WatchRemoteConfigOnChannel() error {
 	return v.watchKeyValueConfigOnChannel()
 }
 
-func (v *Viper) insensitiviseMaps() {
-	insensitiviseMap(v.config)
-	insensitiviseMap(v.defaults)
-	insensitiviseMap(v.override)
-	insensitiviseMap(v.kvstore)
-}
-
 // Retrieve the first found remote configuration.
 func (v *Viper) getKeyValueConfig() error {
 	if RemoteConfig == nil {
@@ -1619,7 +1723,7 @@ func (v *Viper) AllKeys() []string {
 	m = v.flattenAndMergeMap(m, v.defaults, "")
 
 	// convert set of paths to list
-	a := []string{}
+	a := make([]string, 0, len(m))
 	for x := range m {
 		a = append(a, x)
 	}
@@ -1668,7 +1772,7 @@ func (v *Viper) flattenAndMergeMap(shadow map[string]bool, m map[string]interfac
 func (v *Viper) mergeFlatMap(shadow map[string]bool, m map[string]interface{}) map[string]bool {
 	// scan keys
 outer:
-	for k, _ := range m {
+	for k := range m {
 		path := strings.Split(k, v.keyDelim)
 		// scan intermediate paths
 		var parentKey string
@@ -1731,6 +1835,12 @@ func (v *Viper) SetConfigType(in string) {
 	}
 }
 
+// SetConfigPermissions sets the permissions for the config file.
+func SetConfigPermissions(perm os.FileMode) { v.SetConfigPermissions(perm) }
+func (v *Viper) SetConfigPermissions(perm os.FileMode) {
+	v.configPermissions = perm.Perm()
+}
+
 func (v *Viper) getConfigType() string {
 	if v.configType != "" {
 		return v.configType

viper_test.go

@@ -8,23 +8,28 @@ package viper
 import (
 	"bytes"
 	"encoding/json"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path"
+	"path/filepath"
 	"reflect"
+	"runtime"
 	"sort"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
+	"github.com/fsnotify/fsnotify"
 	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/afero"
 	"github.com/spf13/cast"
 
 	"github.com/spf13/pflag"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 var yamlExample = []byte(`Hacker: true
@@ -59,6 +64,11 @@ organization = "MongoDB"
 Bio = "MongoDB Chief Developer Advocate & Hacker at Large"
 dob = 1979-05-27T07:32:00Z # First class dates? Why not?`)
 
+var dotenvExample = []byte(`
+TITLE_DOTENV="DotEnv Example"
+TYPE_DOTENV=donut
+NAME_DOTENV=Cake`)
+
 var jsonExample = []byte(`{
 "id": "0001",
 "type": "donut",
@@ -131,6 +141,10 @@ func initConfigs() {
 	r = bytes.NewReader(tomlExample)
 	unmarshalReader(r, v.config)
 
+	SetConfigType("env")
+	r = bytes.NewReader(dotenvExample)
+	unmarshalReader(r, v.config)
+
 	SetConfigType("json")
 	remote := bytes.NewReader(remoteExample)
 	unmarshalReader(remote, v.kvstore)
@@ -174,6 +188,14 @@ func initTOML() {
 	unmarshalReader(r, v.config)
 }
 
+func initDotEnv() {
+	Reset()
+	SetConfigType("env")
+	r := bytes.NewReader(dotenvExample)
+
+	unmarshalReader(r, v.config)
+}
+
 func initHcl() {
 	Reset()
 	SetConfigType("hcl")
@@ -186,11 +208,16 @@ func initHcl() {
 func initDirs(t *testing.T) (string, string, func()) {
 
 	var (
-		testDirs = []string{`a a`, `b`, `c\c`, `D_`}
+		testDirs = []string{`a a`, `b`, `C_`}
 		config   = `improbable`
 	)
 
+	if runtime.GOOS != "windows" {
+		testDirs = append(testDirs, `d\d`)
+	}
+
 	root, err := ioutil.TempDir("", "")
+	require.NoError(t, err, "Failed to create temporary directory")
 
 	cleanup := true
 	defer func() {
@@ -203,7 +230,7 @@ func initDirs(t *testing.T) (string, string, func()) {
 	assert.Nil(t, err)
 
 	err = os.Chdir(root)
-	assert.Nil(t, err)
+	require.Nil(t, err)
 
 	for _, dir := range testDirs {
 		err = os.Mkdir(dir, 0750)
@@ -223,7 +250,7 @@ func initDirs(t *testing.T) (string, string, func()) {
 	}
 }
 
-//stubs for PFlag Values
+// stubs for PFlag Values
 type stringValue string
 
 func newStringValue(val string, p *string) *stringValue {
@@ -241,7 +268,7 @@ func (s *stringValue) Type() string {
 }
 
 func (s *stringValue) String() string {
-	return fmt.Sprintf("%s", *s)
+	return string(*s)
 }
 
 func TestBasics(t *testing.T) {
@@ -337,6 +364,11 @@ func TestTOML(t *testing.T) {
 	assert.Equal(t, "TOML Example", Get("title"))
 }
 
+func TestDotEnv(t *testing.T) {
+	initDotEnv()
+	assert.Equal(t, "DotEnv Example", Get("title_dotenv"))
+}
+
 func TestHCL(t *testing.T) {
 	initHcl()
 	assert.Equal(t, "0001", Get("id"))
@@ -383,6 +415,42 @@ func TestEnv(t *testing.T) {
 
 }
 
+func TestEmptyEnv(t *testing.T) {
+	initJSON()
+
+	BindEnv("type") // Empty environment variable
+	BindEnv("name") // Bound, but not set environment variable
+
+	os.Unsetenv("type")
+	os.Unsetenv("TYPE")
+	os.Unsetenv("name")
+	os.Unsetenv("NAME")
+
+	os.Setenv("TYPE", "")
+
+	assert.Equal(t, "donut", Get("type"))
+	assert.Equal(t, "Cake", Get("name"))
+}
+
+func TestEmptyEnv_Allowed(t *testing.T) {
+	initJSON()
+
+	AllowEmptyEnv(true)
+
+	BindEnv("type") // Empty environment variable
+	BindEnv("name") // Bound, but not set environment variable
+
+	os.Unsetenv("type")
+	os.Unsetenv("TYPE")
+	os.Unsetenv("name")
+	os.Unsetenv("NAME")
+
+	os.Setenv("TYPE", "")
+
+	assert.Equal(t, "", Get("type"))
+	assert.Equal(t, "Cake", Get("name"))
+}
+
 func TestEnvPrefix(t *testing.T) {
 	initJSON()
 
@@ -435,12 +503,92 @@ func TestSetEnvKeyReplacer(t *testing.T) {
 func TestAllKeys(t *testing.T) {
 	initConfigs()
 
-	ks := sort.StringSlice{"title", "newkey", "owner.organization", "owner.dob", "owner.bio", "name", "beard", "ppu", "batters.batter", "hobbies", "clothing.jacket", "clothing.trousers", "clothing.pants.size", "age", "hacker", "id", "type", "eyes", "p_id", "p_ppu", "p_batters.batter.type", "p_type", "p_name", "foos"}
+	ks := sort.StringSlice{
+		"title",
+		"newkey",
+		"owner.organization",
+		"owner.dob",
+		"owner.bio",
+		"name",
+		"beard",
+		"ppu",
+		"batters.batter",
+		"hobbies",
+		"clothing.jacket",
+		"clothing.trousers",
+		"clothing.pants.size",
+		"age",
+		"hacker",
+		"id",
+		"type",
+		"eyes",
+		"p_id",
+		"p_ppu",
+		"p_batters.batter.type",
+		"p_type",
+		"p_name",
+		"foos",
+		"title_dotenv",
+		"type_dotenv",
+		"name_dotenv",
+	}
 	dob, _ := time.Parse(time.RFC3339, "1979-05-27T07:32:00Z")
-	all := map[string]interface{}{"owner": map[string]interface{}{"organization": "MongoDB", "bio": "MongoDB Chief Developer Advocate & Hacker at Large", "dob": dob}, "title": "TOML Example", "ppu": 0.55, "eyes": "brown", "clothing": map[string]interface{}{"trousers": "denim", "jacket": "leather", "pants": map[string]interface{}{"size": "large"}}, "id": "0001", "batters": map[string]interface{}{"batter": []interface{}{map[string]interface{}{"type": "Regular"}, map[string]interface{}{"type": "Chocolate"}, map[string]interface{}{"type": "Blueberry"}, map[string]interface{}{"type": "Devil's Food"}}}, "hacker": true, "beard": true, "hobbies": []interface{}{"skateboarding", "snowboarding", "go"}, "age": 35, "type": "donut", "newkey": "remote", "name": "Cake", "p_id": "0001", "p_ppu": "0.55", "p_name": "Cake", "p_batters": map[string]interface{}{"batter": map[string]interface{}{"type": "Regular"}}, "p_type": "donut", "foos": []map[string]interface{}{map[string]interface{}{"foo": []map[string]interface{}{map[string]interface{}{"key": 1}, map[string]interface{}{"key": 2}, map[string]interface{}{"key": 3}, map[string]interface{}{"key": 4}}}}}
+	all := map[string]interface{}{
+		"owner": map[string]interface{}{
+			"organization": "MongoDB",
+			"bio":          "MongoDB Chief Developer Advocate & Hacker at Large",
+			"dob":          dob,
+		},
+		"title": "TOML Example",
+		"ppu":   0.55,
+		"eyes":  "brown",
+		"clothing": map[string]interface{}{
+			"trousers": "denim",
+			"jacket":   "leather",
+			"pants":    map[string]interface{}{"size": "large"},
+		},
+		"id": "0001",
+		"batters": map[string]interface{}{
+			"batter": []interface{}{
+				map[string]interface{}{"type": "Regular"},
+				map[string]interface{}{"type": "Chocolate"},
+				map[string]interface{}{"type": "Blueberry"},
+				map[string]interface{}{"type": "Devil's Food"},
+			},
+		},
+		"hacker": true,
+		"beard":  true,
+		"hobbies": []interface{}{
+			"skateboarding",
+			"snowboarding",
+			"go",
+		},
+		"age":    35,
+		"type":   "donut",
+		"newkey": "remote",
+		"name":   "Cake",
+		"p_id":   "0001",
+		"p_ppu":  "0.55",
+		"p_name": "Cake",
+		"p_batters": map[string]interface{}{
+			"batter": map[string]interface{}{"type": "Regular"},
+		},
+		"p_type": "donut",
+		"foos": []map[string]interface{}{
+			{
+				"foo": []map[string]interface{}{
+					{"key": 1},
+					{"key": 2},
+					{"key": 3},
+					{"key": 4}},
+			},
+		},
+		"title_dotenv": "DotEnv Example",
+		"type_dotenv":  "donut",
+		"name_dotenv":  "Cake",
+	}
 
-	var allkeys sort.StringSlice
-	allkeys = AllKeys()
+	allkeys := sort.StringSlice(AllKeys())
 	allkeys.Sort()
 	ks.Sort()
 
@@ -481,11 +629,13 @@ func TestUnmarshal(t *testing.T) {
 	SetDefault("port", 1313)
 	Set("name", "Steve")
 	Set("duration", "1s1ms")
+	Set("modes", []int{1, 2, 3})
 
 	type config struct {
 		Port     int
 		Name     string
 		Duration time.Duration
+		Modes    []int
 	}
 
 	var C config
@@ -495,14 +645,33 @@ func TestUnmarshal(t *testing.T) {
 		t.Fatalf("unable to decode into struct, %v", err)
 	}
 
-	assert.Equal(t, &config{Name: "Steve", Port: 1313, Duration: time.Second + time.Millisecond}, &C)
+	assert.Equal(
+		t,
+		&config{
+			Name:     "Steve",
+			Port:     1313,
+			Duration: time.Second + time.Millisecond,
+			Modes:    []int{1, 2, 3},
+		},
+		&C,
+	)
 
 	Set("port", 1234)
 	err = Unmarshal(&C)
 	if err != nil {
 		t.Fatalf("unable to decode into struct, %v", err)
 	}
-	assert.Equal(t, &config{Name: "Steve", Port: 1234, Duration: time.Second + time.Millisecond}, &C)
+
+	assert.Equal(
+		t,
+		&config{
+			Name:     "Steve",
+			Port:     1234,
+			Duration: time.Second + time.Millisecond,
+			Modes:    []int{1, 2, 3},
+		},
+		&C,
+	)
 }
 
 func TestUnmarshalWithDecoderOptions(t *testing.T) {
@@ -578,24 +747,28 @@ func TestBindPFlags(t *testing.T) {
 }
 
 func TestBindPFlagsStringSlice(t *testing.T) {
-	for _, testValue := range []struct {
+	tests := []struct {
 		Expected []string
 		Value    string
 	}{
-		{[]string{}, ""},
+		{nil, ""},
 		{[]string{"jeden"}, "jeden"},
 		{[]string{"dwa", "trzy"}, "dwa,trzy"},
-		{[]string{"cztery", "piec , szesc"}, "cztery,\"piec , szesc\""}} {
+		{[]string{"cztery", "piec , szesc"}, "cztery,\"piec , szesc\""},
+	}
+
+	v := New() // create independent Viper object
+	defaultVal := []string{"default"}
+	v.SetDefault("stringslice", defaultVal)
+
+	for _, testValue := range tests {
+		flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
+		flagSet.StringSlice("stringslice", testValue.Expected, "test")
 
 		for _, changed := range []bool{true, false} {
-			v := New() // create independent Viper object
-			flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
-			flagSet.StringSlice("stringslice", testValue.Expected, "test")
-			flagSet.Visit(func(f *pflag.Flag) {
-				if len(testValue.Value) > 0 {
-					f.Value.Set(testValue.Value)
-					f.Changed = changed
-				}
+			flagSet.VisitAll(func(f *pflag.Flag) {
+				f.Value.Set(testValue.Value)
+				f.Changed = changed
 			})
 
 			err := v.BindPFlags(flagSet)
@@ -610,7 +783,56 @@ func TestBindPFlagsStringSlice(t *testing.T) {
 			if err := v.Unmarshal(val); err != nil {
 				t.Fatalf("%+#v cannot unmarshal: %s", testValue.Value, err)
 			}
-			assert.Equal(t, testValue.Expected, val.StringSlice)
+			if changed {
+				assert.Equal(t, testValue.Expected, val.StringSlice)
+			} else {
+				assert.Equal(t, defaultVal, val.StringSlice)
+			}
+		}
+	}
+}
+
+func TestBindPFlagsIntSlice(t *testing.T) {
+	tests := []struct {
+		Expected []int
+		Value    string
+	}{
+		{nil, ""},
+		{[]int{1}, "1"},
+		{[]int{2, 3}, "2,3"},
+	}
+
+	v := New() // create independent Viper object
+	defaultVal := []int{0}
+	v.SetDefault("intslice", defaultVal)
+
+	for _, testValue := range tests {
+		flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
+		flagSet.IntSlice("intslice", testValue.Expected, "test")
+
+		for _, changed := range []bool{true, false} {
+			flagSet.VisitAll(func(f *pflag.Flag) {
+				f.Value.Set(testValue.Value)
+				f.Changed = changed
+			})
+
+			err := v.BindPFlags(flagSet)
+			if err != nil {
+				t.Fatalf("error binding flag set, %v", err)
+			}
+
+			type TestInt struct {
+				IntSlice []int
+			}
+			val := &TestInt{}
+			if err := v.Unmarshal(val); err != nil {
+				t.Fatalf("%+#v cannot unmarshal: %s", testValue.Value, err)
+			}
+			if changed {
+				assert.Equal(t, testValue.Expected, val.IntSlice)
+			} else {
+				assert.Equal(t, defaultVal, val.IntSlice)
+			}
 		}
 	}
 }
@@ -630,7 +852,7 @@ func TestBindPFlag(t *testing.T) {
 	assert.Equal(t, testString, Get("testvalue"))
 
 	flag.Value.Set("testing_mutate")
-	flag.Changed = true //hack for pflag usage
+	flag.Changed = true // hack for pflag usage
 
 	assert.Equal(t, "testing_mutate", Get("testvalue"))
 
@@ -713,8 +935,11 @@ func TestFindsNestedKeys(t *testing.T) {
 		"hobbies": []interface{}{
 			"skateboarding", "snowboarding", "go",
 		},
-		"title":  "TOML Example",
-		"newkey": "remote",
+		"TITLE_DOTENV": "DotEnv Example",
+		"TYPE_DOTENV":  "donut",
+		"NAME_DOTENV":  "Cake",
+		"title":        "TOML Example",
+		"newkey":       "remote",
 		"batters": map[string]interface{}{
 			"batter": []interface{}{
 				map[string]interface{}{
@@ -816,6 +1041,7 @@ func TestDirsSearch(t *testing.T) {
 	v.SetDefault(`key`, `default`)
 
 	entries, err := ioutil.ReadDir(root)
+	assert.Nil(t, err)
 	for _, e := range entries {
 		if e.IsDir() {
 			v.AddConfigPath(e.Name())
@@ -825,7 +1051,7 @@ func TestDirsSearch(t *testing.T) {
 	err = v.ReadInConfig()
 	assert.Nil(t, err)
 
-	assert.Equal(t, `value is `+path.Base(v.configPaths[0]), v.GetString(`key`))
+	assert.Equal(t, `value is `+filepath.Base(v.configPaths[0]), v.GetString(`key`))
 }
 
 func TestWrongDirsSearchNotFound(t *testing.T) {
@@ -1034,6 +1260,43 @@ func TestWriteConfigTOML(t *testing.T) {
 	assert.Equal(t, v.GetString("owner.organization"), v2.GetString("owner.organization"))
 }
 
+var dotenvWriteExpected = []byte(`
+TITLE="DotEnv Write Example"
+NAME=Oreo
+KIND=Biscuit
+`)
+
+func TestWriteConfigDotEnv(t *testing.T) {
+	fs := afero.NewMemMapFs()
+	v := New()
+	v.SetFs(fs)
+	v.SetConfigName("c")
+	v.SetConfigType("env")
+	err := v.ReadConfig(bytes.NewBuffer(dotenvWriteExpected))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := v.WriteConfigAs("c.env"); err != nil {
+		t.Fatal(err)
+	}
+
+	// The TOML String method does not order the contents.
+	// Therefore, we must read the generated file and compare the data.
+	v2 := New()
+	v2.SetFs(fs)
+	v2.SetConfigName("c")
+	v2.SetConfigType("env")
+	v2.SetConfigFile("c.env")
+	err = v2.ReadInConfig()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	assert.Equal(t, v.GetString("title"), v2.GetString("title"))
+	assert.Equal(t, v.GetString("type"), v2.GetString("type"))
+	assert.Equal(t, v.GetString("kind"), v2.GetString("kind"))
+}
+
 var yamlWriteExpected = []byte(`age: 35
 beard: true
 clothing:
@@ -1073,7 +1336,8 @@ func TestWriteConfigYAML(t *testing.T) {
 var yamlMergeExampleTgt = []byte(`
 hello:
     pop: 37890
-    lagrenum: 765432101234567
+    largenum: 765432101234567
+    num2pow63: 9223372036854775808
     world:
     - us
     - uk
@@ -1084,10 +1348,13 @@ hello:
 var yamlMergeExampleSrc = []byte(`
 hello:
     pop: 45000
-    lagrenum: 7654321001234567
+    largenum: 7654321001234567
     universe:
     - mw
     - ad
+    ints:
+    - 1
+    - 2
 fu: bar
 `)
 
@@ -1102,16 +1369,24 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("pop != 37890, = %d", pop)
 	}
 
-	if pop := v.GetInt("hello.lagrenum"); pop != 765432101234567 {
-		t.Fatalf("lagrenum != 765432101234567, = %d", pop)
-	}
-
 	if pop := v.GetInt32("hello.pop"); pop != int32(37890) {
 		t.Fatalf("pop != 37890, = %d", pop)
 	}
 
-	if pop := v.GetInt64("hello.lagrenum"); pop != int64(765432101234567) {
-		t.Fatalf("int64 lagrenum != 765432101234567, = %d", pop)
+	if pop := v.GetInt64("hello.largenum"); pop != int64(765432101234567) {
+		t.Fatalf("int64 largenum != 765432101234567, = %d", pop)
+	}
+
+	if pop := v.GetUint("hello.pop"); pop != 37890 {
+		t.Fatalf("uint pop != 37890, = %d", pop)
+	}
+
+	if pop := v.GetUint32("hello.pop"); pop != 37890 {
+		t.Fatalf("uint32 pop != 37890, = %d", pop)
+	}
+
+	if pop := v.GetUint64("hello.num2pow63"); pop != 9223372036854775808 {
+		t.Fatalf("uint64 num2pow63 != 9223372036854775808, = %d", pop)
 	}
 
 	if world := v.GetStringSlice("hello.world"); len(world) != 4 {
@@ -1130,16 +1405,12 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("pop != 45000, = %d", pop)
 	}
 
-	if pop := v.GetInt("hello.lagrenum"); pop != 7654321001234567 {
-		t.Fatalf("lagrenum != 7654321001234567, = %d", pop)
-	}
-
 	if pop := v.GetInt32("hello.pop"); pop != int32(45000) {
 		t.Fatalf("pop != 45000, = %d", pop)
 	}
 
-	if pop := v.GetInt64("hello.lagrenum"); pop != int64(7654321001234567) {
-		t.Fatalf("int64 lagrenum != 7654321001234567, = %d", pop)
+	if pop := v.GetInt64("hello.largenum"); pop != int64(7654321001234567) {
+		t.Fatalf("int64 largenum != 7654321001234567, = %d", pop)
 	}
 
 	if world := v.GetStringSlice("hello.world"); len(world) != 4 {
@@ -1150,6 +1421,10 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("len(universe) != 2, = %d", len(universe))
 	}
 
+	if ints := v.GetIntSlice("hello.ints"); len(ints) != 2 {
+		t.Fatalf("len(ints) != 2, = %d", len(ints))
+	}
+
 	if fu := v.GetString("fu"); fu != "bar" {
 		t.Fatalf("fu != \"bar\", = %s", fu)
 	}
@@ -1190,11 +1465,57 @@ func TestMergeConfigNoMerge(t *testing.T) {
 		t.Fatalf("len(universe) != 2, = %d", len(universe))
 	}
 
+	if ints := v.GetIntSlice("hello.ints"); len(ints) != 2 {
+		t.Fatalf("len(ints) != 2, = %d", len(ints))
+	}
+
 	if fu := v.GetString("fu"); fu != "bar" {
 		t.Fatalf("fu != \"bar\", = %s", fu)
 	}
 }
 
+func TestMergeConfigMap(t *testing.T) {
+	v := New()
+	v.SetConfigType("yml")
+	if err := v.ReadConfig(bytes.NewBuffer(yamlMergeExampleTgt)); err != nil {
+		t.Fatal(err)
+	}
+
+	assert := func(i int) {
+		large := v.GetInt64("hello.largenum")
+		pop := v.GetInt("hello.pop")
+		if large != 765432101234567 {
+			t.Fatal("Got large num:", large)
+		}
+
+		if pop != i {
+			t.Fatal("Got pop:", pop)
+		}
+	}
+
+	assert(37890)
+
+	update := map[string]interface{}{
+		"Hello": map[string]interface{}{
+			"Pop": 1234,
+		},
+		"World": map[interface{}]interface{}{
+			"Rock": 345,
+		},
+	}
+
+	if err := v.MergeConfigMap(update); err != nil {
+		t.Fatal(err)
+	}
+
+	if rock := v.GetInt("world.rock"); rock != 345 {
+		t.Fatal("Got rock:", rock)
+	}
+
+	assert(1234)
+
+}
+
 func TestUnmarshalingWithAliases(t *testing.T) {
 	v := New()
 	v.SetDefault("ID", 1)
@@ -1414,6 +1735,128 @@ func doTestCaseInsensitive(t *testing.T, typ, config string) {
 
 }
 
+func newViperWithConfigFile(t *testing.T) (*Viper, string, func()) {
+	watchDir, err := ioutil.TempDir("", "")
+	require.Nil(t, err)
+	configFile := path.Join(watchDir, "config.yaml")
+	err = ioutil.WriteFile(configFile, []byte("foo: bar\n"), 0640)
+	require.Nil(t, err)
+	cleanup := func() {
+		os.RemoveAll(watchDir)
+	}
+	v := New()
+	v.SetConfigFile(configFile)
+	err = v.ReadInConfig()
+	require.Nil(t, err)
+	require.Equal(t, "bar", v.Get("foo"))
+	return v, configFile, cleanup
+}
+
+func newViperWithSymlinkedConfigFile(t *testing.T) (*Viper, string, string, func()) {
+	watchDir, err := ioutil.TempDir("", "")
+	require.Nil(t, err)
+	dataDir1 := path.Join(watchDir, "data1")
+	err = os.Mkdir(dataDir1, 0777)
+	require.Nil(t, err)
+	realConfigFile := path.Join(dataDir1, "config.yaml")
+	t.Logf("Real config file location: %s\n", realConfigFile)
+	err = ioutil.WriteFile(realConfigFile, []byte("foo: bar\n"), 0640)
+	require.Nil(t, err)
+	cleanup := func() {
+		os.RemoveAll(watchDir)
+	}
+	// now, symlink the tm `data1` dir to `data` in the baseDir
+	os.Symlink(dataDir1, path.Join(watchDir, "data"))
+	// and link the `<watchdir>/datadir1/config.yaml` to `<watchdir>/config.yaml`
+	configFile := path.Join(watchDir, "config.yaml")
+	os.Symlink(path.Join(watchDir, "data", "config.yaml"), configFile)
+	t.Logf("Config file location: %s\n", path.Join(watchDir, "config.yaml"))
+	// init Viper
+	v := New()
+	v.SetConfigFile(configFile)
+	err = v.ReadInConfig()
+	require.Nil(t, err)
+	require.Equal(t, "bar", v.Get("foo"))
+	return v, watchDir, configFile, cleanup
+}
+
+func TestWatchFile(t *testing.T) {
+	if runtime.GOOS == "linux" {
+		// TODO(bep) FIX ME
+		t.Skip("Skip test on Linux ...")
+	}
+
+	t.Run("file content changed", func(t *testing.T) {
+		// given a `config.yaml` file being watched
+		v, configFile, cleanup := newViperWithConfigFile(t)
+		defer cleanup()
+		_, err := os.Stat(configFile)
+		require.NoError(t, err)
+		t.Logf("test config file: %s\n", configFile)
+		wg := sync.WaitGroup{}
+		wg.Add(1)
+		v.OnConfigChange(func(in fsnotify.Event) {
+			t.Logf("config file changed")
+			wg.Done()
+		})
+		v.WatchConfig()
+		// when overwriting the file and waiting for the custom change notification handler to be triggered
+		err = ioutil.WriteFile(configFile, []byte("foo: baz\n"), 0640)
+		wg.Wait()
+		// then the config value should have changed
+		require.Nil(t, err)
+		assert.Equal(t, "baz", v.Get("foo"))
+	})
+
+	t.Run("link to real file changed (à la Kubernetes)", func(t *testing.T) {
+		// skip if not executed on Linux
+		if runtime.GOOS != "linux" {
+			t.Skipf("Skipping test as symlink replacements don't work on non-linux environment...")
+		}
+		v, watchDir, _, _ := newViperWithSymlinkedConfigFile(t)
+		// defer cleanup()
+		wg := sync.WaitGroup{}
+		v.WatchConfig()
+		v.OnConfigChange(func(in fsnotify.Event) {
+			t.Logf("config file changed")
+			wg.Done()
+		})
+		wg.Add(1)
+		// when link to another `config.yaml` file
+		dataDir2 := path.Join(watchDir, "data2")
+		err := os.Mkdir(dataDir2, 0777)
+		require.Nil(t, err)
+		configFile2 := path.Join(dataDir2, "config.yaml")
+		err = ioutil.WriteFile(configFile2, []byte("foo: baz\n"), 0640)
+		require.Nil(t, err)
+		// change the symlink using the `ln -sfn` command
+		err = exec.Command("ln", "-sfn", dataDir2, path.Join(watchDir, "data")).Run()
+		require.Nil(t, err)
+		wg.Wait()
+		// then
+		require.Nil(t, err)
+		assert.Equal(t, "baz", v.Get("foo"))
+	})
+
+}
+
+func TestUnmarshal_DotSeparatorBackwardCompatibility(t *testing.T) {
+	flags := pflag.NewFlagSet("test", pflag.ContinueOnError)
+	flags.String("foo.bar", "cobra_flag", "")
+
+	v := New()
+	assert.NoError(t, v.BindPFlags(flags))
+
+	config := &struct {
+		Foo struct {
+			Bar string
+		}
+	}{}
+
+	assert.NoError(t, v.Unmarshal(config))
+	assert.Equal(t, "cobra_flag", config.Foo.Bar)
+}
+
 func BenchmarkGetBool(b *testing.B) {
 	key := "BenchmarkGetBool"
 	v = New()
@@ -1438,7 +1881,7 @@ func BenchmarkGet(b *testing.B) {
 	}
 }
 
-// This is the "perfect result" for the above.
+// BenchmarkGetBoolFromMap is the "perfect result" for the above.
 func BenchmarkGetBoolFromMap(b *testing.B) {
 	m := make(map[string]bool)
 	key := "BenchmarkGetBool"