diff --git a/encoding/gjson/gjson_api.go b/encoding/gjson/gjson_api.go
index fdc9af723..59e1d90da 100644
--- a/encoding/gjson/gjson_api.go
+++ b/encoding/gjson/gjson_api.go
@@ -150,13 +150,13 @@ func (j *Json) GetString(pattern string, def ...interface{}) string {
 	return gconv.String(j.Get(pattern, def...))
 }
 
-// GetBytes retrieves the value by specified <pattern> and converts it to byte.
+// GetBytes retrieves the value by specified <pattern> and converts it to []byte.
 func (j *Json) GetBytes(pattern string, def ...interface{}) []byte {
 	return gconv.Bytes(j.Get(pattern, def...))
 }
 
-// GetBool gets the value by specified <pattern>,
-// and converts it to bool.
+// GetBool retrieves the value by specified <pattern>,
+// converts and returns it as bool.
 // It returns false when value is: "", 0, false, off, nil;
 // or returns true instead.
 func (j *Json) GetBool(pattern string, def ...interface{}) bool {
diff --git a/go.mod b/go.mod
index 682fb3f61..aefe27958 100644
--- a/go.mod
+++ b/go.mod
@@ -14,8 +14,8 @@ require (
 	github.com/json-iterator/go v1.1.10
 	github.com/mattn/go-runewidth v0.0.9 // indirect
 	github.com/olekukonko/tablewriter v0.0.1
-	golang.org/x/sys v0.0.0-20200625212154-ddb9806d33ae // indirect
 	golang.org/x/net v0.0.0-20200602114024-627f9648deb9
+	golang.org/x/sys v0.0.0-20200625212154-ddb9806d33ae // indirect
 	golang.org/x/text v0.3.2
 	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c
 )
diff --git a/os/gcfg/gcfg.go b/os/gcfg/gcfg.go
index 0f1f8babb..b0ae54ed6 100644
--- a/os/gcfg/gcfg.go
+++ b/os/gcfg/gcfg.go
@@ -328,8 +328,10 @@ func (c *Config) getJson(file ...string) *gjson.Json {
 		name = c.name
 	}
 	r := c.jsons.GetOrSetFuncLock(name, func() interface{} {
-		content := ""
-		filePath := ""
+		var (
+			content  = ""
+			filePath = ""
+		)
 		if content = GetContent(name); content == "" {
 			filePath = c.filePath(name)
 			if filePath == "" {
@@ -341,6 +343,7 @@ func (c *Config) getJson(file ...string) *gjson.Json {
 				content = gfile.GetContents(filePath)
 			}
 		}
+		// Note that the underlying configuration json object operations are concurrent safe.
 		if j, err := gjson.LoadContent(content, true); err == nil {
 			j.SetViolenceCheck(c.vc)
 			// Add monitor for this configuration file,
diff --git a/os/gcfg/gcfg_api.go b/os/gcfg/gcfg_api.go
index 9956f751f..f104e4f39 100644
--- a/os/gcfg/gcfg_api.go
+++ b/os/gcfg/gcfg_api.go
@@ -16,6 +16,24 @@ import (
 	"github.com/gogf/gf/os/gtime"
 )
 
+// Set sets value with specified <pattern>.
+// It supports hierarchical data access by char separator, which is '.' in default.
+// It is commonly used for updates certain configuration value in runtime.
+func (c *Config) Set(pattern string, value interface{}) error {
+	if j := c.getJson(); j != nil {
+		return j.Set(pattern, value)
+	}
+	return nil
+}
+
+// Get retrieves and returns value by specified <pattern>.
+// It returns all values of current Json object if <pattern> is given empty or string ".".
+// It returns nil if no value found by <pattern>.
+//
+// We can also access slice item by its index number in <pattern> like:
+// "list.10", "array.0.name", "array.0.1.id".
+//
+// It returns a default value specified by <def> if value for <pattern> is not found.
 func (c *Config) Get(pattern string, def ...interface{}) interface{} {
 	if j := c.getJson(); j != nil {
 		return j.Get(pattern, def...)
@@ -23,13 +41,15 @@ func (c *Config) Get(pattern string, def ...interface{}) interface{} {
 	return nil
 }
 
+// GetVar returns a gvar.Var with value by given <pattern>.
 func (c *Config) GetVar(pattern string, def ...interface{}) *gvar.Var {
 	if j := c.getJson(); j != nil {
-		return gvar.New(j.Get(pattern, def...))
+		return j.GetVar(pattern, def...)
 	}
 	return gvar.New(nil)
 }
 
+// Contains checks whether the value by specified <pattern> exist.
 func (c *Config) Contains(pattern string) bool {
 	if j := c.getJson(); j != nil {
 		return j.Contains(pattern)
@@ -37,6 +57,7 @@ func (c *Config) Contains(pattern string) bool {
 	return false
 }
 
+// GetMap retrieves and returns the value by specified <pattern> as map[string]interface{}.
 func (c *Config) GetMap(pattern string, def ...interface{}) map[string]interface{} {
 	if j := c.getJson(); j != nil {
 		return j.GetMap(pattern, def...)
@@ -44,6 +65,7 @@ func (c *Config) GetMap(pattern string, def ...interface{}) map[string]interface
 	return nil
 }
 
+// GetMapStrStr retrieves and returns the value by specified <pattern> as map[string]string.
 func (c *Config) GetMapStrStr(pattern string, def ...interface{}) map[string]string {
 	if j := c.getJson(); j != nil {
 		return j.GetMapStrStr(pattern, def...)
@@ -51,6 +73,8 @@ func (c *Config) GetMapStrStr(pattern string, def ...interface{}) map[string]str
 	return nil
 }
 
+// GetArray retrieves the value by specified <pattern>,
+// and converts it to a slice of []interface{}.
 func (c *Config) GetArray(pattern string, def ...interface{}) []interface{} {
 	if j := c.getJson(); j != nil {
 		return j.GetArray(pattern, def...)
@@ -58,6 +82,7 @@ func (c *Config) GetArray(pattern string, def ...interface{}) []interface{} {
 	return nil
 }
 
+// GetBytes retrieves the value by specified <pattern> and converts it to []byte.
 func (c *Config) GetBytes(pattern string, def ...interface{}) []byte {
 	if j := c.getJson(); j != nil {
 		return j.GetBytes(pattern, def...)
@@ -65,6 +90,7 @@ func (c *Config) GetBytes(pattern string, def ...interface{}) []byte {
 	return nil
 }
 
+// GetString retrieves the value by specified <pattern> and converts it to string.
 func (c *Config) GetString(pattern string, def ...interface{}) string {
 	if j := c.getJson(); j != nil {
 		return j.GetString(pattern, def...)
@@ -72,6 +98,7 @@ func (c *Config) GetString(pattern string, def ...interface{}) string {
 	return ""
 }
 
+// GetStrings retrieves the value by specified <pattern> and converts it to []string.
 func (c *Config) GetStrings(pattern string, def ...interface{}) []string {
 	if j := c.getJson(); j != nil {
 		return j.GetStrings(pattern, def...)
@@ -79,6 +106,8 @@ func (c *Config) GetStrings(pattern string, def ...interface{}) []string {
 	return nil
 }
 
+// GetInterfaces is alias of GetArray.
+// See GetArray.
 func (c *Config) GetInterfaces(pattern string, def ...interface{}) []interface{} {
 	if j := c.getJson(); j != nil {
 		return j.GetInterfaces(pattern, def...)
@@ -86,6 +115,10 @@ func (c *Config) GetInterfaces(pattern string, def ...interface{}) []interface{}
 	return nil
 }
 
+// GetBool retrieves the value by specified <pattern>,
+// converts and returns it as bool.
+// It returns false when value is: "", 0, false, off, nil;
+// or returns true instead.
 func (c *Config) GetBool(pattern string, def ...interface{}) bool {
 	if j := c.getJson(); j != nil {
 		return j.GetBool(pattern, def...)
@@ -93,6 +126,7 @@ func (c *Config) GetBool(pattern string, def ...interface{}) bool {
 	return false
 }
 
+// GetFloat32 retrieves the value by specified <pattern> and converts it to float32.
 func (c *Config) GetFloat32(pattern string, def ...interface{}) float32 {
 	if j := c.getJson(); j != nil {
 		return j.GetFloat32(pattern, def...)
@@ -100,6 +134,7 @@ func (c *Config) GetFloat32(pattern string, def ...interface{}) float32 {
 	return 0
 }
 
+// GetFloat64 retrieves the value by specified <pattern> and converts it to float64.
 func (c *Config) GetFloat64(pattern string, def ...interface{}) float64 {
 	if j := c.getJson(); j != nil {
 		return j.GetFloat64(pattern, def...)
@@ -107,6 +142,7 @@ func (c *Config) GetFloat64(pattern string, def ...interface{}) float64 {
 	return 0
 }
 
+// GetFloats retrieves the value by specified <pattern> and converts it to []float64.
 func (c *Config) GetFloats(pattern string, def ...interface{}) []float64 {
 	if j := c.getJson(); j != nil {
 		return j.GetFloats(pattern, def...)
@@ -114,6 +150,7 @@ func (c *Config) GetFloats(pattern string, def ...interface{}) []float64 {
 	return nil
 }
 
+// GetInt retrieves the value by specified <pattern> and converts it to int.
 func (c *Config) GetInt(pattern string, def ...interface{}) int {
 	if j := c.getJson(); j != nil {
 		return j.GetInt(pattern, def...)
@@ -121,6 +158,7 @@ func (c *Config) GetInt(pattern string, def ...interface{}) int {
 	return 0
 }
 
+// GetInt8 retrieves the value by specified <pattern> and converts it to int8.
 func (c *Config) GetInt8(pattern string, def ...interface{}) int8 {
 	if j := c.getJson(); j != nil {
 		return j.GetInt8(pattern, def...)
@@ -128,6 +166,7 @@ func (c *Config) GetInt8(pattern string, def ...interface{}) int8 {
 	return 0
 }
 
+// GetInt16 retrieves the value by specified <pattern> and converts it to int16.
 func (c *Config) GetInt16(pattern string, def ...interface{}) int16 {
 	if j := c.getJson(); j != nil {
 		return j.GetInt16(pattern, def...)
@@ -135,6 +174,7 @@ func (c *Config) GetInt16(pattern string, def ...interface{}) int16 {
 	return 0
 }
 
+// GetInt32 retrieves the value by specified <pattern> and converts it to int32.
 func (c *Config) GetInt32(pattern string, def ...interface{}) int32 {
 	if j := c.getJson(); j != nil {
 		return j.GetInt32(pattern, def...)
@@ -142,6 +182,7 @@ func (c *Config) GetInt32(pattern string, def ...interface{}) int32 {
 	return 0
 }
 
+// GetInt64 retrieves the value by specified <pattern> and converts it to int64.
 func (c *Config) GetInt64(pattern string, def ...interface{}) int64 {
 	if j := c.getJson(); j != nil {
 		return j.GetInt64(pattern, def...)
@@ -149,6 +190,7 @@ func (c *Config) GetInt64(pattern string, def ...interface{}) int64 {
 	return 0
 }
 
+// GetInts retrieves the value by specified <pattern> and converts it to []int.
 func (c *Config) GetInts(pattern string, def ...interface{}) []int {
 	if j := c.getJson(); j != nil {
 		return j.GetInts(pattern, def...)
@@ -156,6 +198,7 @@ func (c *Config) GetInts(pattern string, def ...interface{}) []int {
 	return nil
 }
 
+// GetUint retrieves the value by specified <pattern> and converts it to uint.
 func (c *Config) GetUint(pattern string, def ...interface{}) uint {
 	if j := c.getJson(); j != nil {
 		return j.GetUint(pattern, def...)
@@ -163,6 +206,7 @@ func (c *Config) GetUint(pattern string, def ...interface{}) uint {
 	return 0
 }
 
+// GetUint8 retrieves the value by specified <pattern> and converts it to uint8.
 func (c *Config) GetUint8(pattern string, def ...interface{}) uint8 {
 	if j := c.getJson(); j != nil {
 		return j.GetUint8(pattern, def...)
@@ -170,6 +214,7 @@ func (c *Config) GetUint8(pattern string, def ...interface{}) uint8 {
 	return 0
 }
 
+// GetUint16 retrieves the value by specified <pattern> and converts it to uint16.
 func (c *Config) GetUint16(pattern string, def ...interface{}) uint16 {
 	if j := c.getJson(); j != nil {
 		return j.GetUint16(pattern, def...)
@@ -177,6 +222,7 @@ func (c *Config) GetUint16(pattern string, def ...interface{}) uint16 {
 	return 0
 }
 
+// GetUint32 retrieves the value by specified <pattern> and converts it to uint32.
 func (c *Config) GetUint32(pattern string, def ...interface{}) uint32 {
 	if j := c.getJson(); j != nil {
 		return j.GetUint32(pattern, def...)
@@ -184,6 +230,7 @@ func (c *Config) GetUint32(pattern string, def ...interface{}) uint32 {
 	return 0
 }
 
+// GetUint64 retrieves the value by specified <pattern> and converts it to uint64.
 func (c *Config) GetUint64(pattern string, def ...interface{}) uint64 {
 	if j := c.getJson(); j != nil {
 		return j.GetUint64(pattern, def...)
@@ -191,6 +238,7 @@ func (c *Config) GetUint64(pattern string, def ...interface{}) uint64 {
 	return 0
 }
 
+// GetTime retrieves the value by specified <pattern> and converts it to time.Time.
 func (c *Config) GetTime(pattern string, format ...string) time.Time {
 	if j := c.getJson(); j != nil {
 		return j.GetTime(pattern, format...)
@@ -198,6 +246,7 @@ func (c *Config) GetTime(pattern string, format ...string) time.Time {
 	return time.Time{}
 }
 
+// GetDuration retrieves the value by specified <pattern> and converts it to time.Duration.
 func (c *Config) GetDuration(pattern string, def ...interface{}) time.Duration {
 	if j := c.getJson(); j != nil {
 		return j.GetDuration(pattern, def...)
@@ -205,6 +254,7 @@ func (c *Config) GetDuration(pattern string, def ...interface{}) time.Duration {
 	return 0
 }
 
+// GetGTime retrieves the value by specified <pattern> and converts it to *gtime.Time.
 func (c *Config) GetGTime(pattern string, format ...string) *gtime.Time {
 	if j := c.getJson(); j != nil {
 		return j.GetGTime(pattern, format...)
@@ -212,6 +262,8 @@ func (c *Config) GetGTime(pattern string, format ...string) *gtime.Time {
 	return nil
 }
 
+// GetJson gets the value by specified <pattern>,
+// and converts it to a un-concurrent-safe Json object.
 func (c *Config) GetJson(pattern string, def ...interface{}) *gjson.Json {
 	if j := c.getJson(); j != nil {
 		return j.GetJson(pattern, def...)
@@ -219,6 +271,8 @@ func (c *Config) GetJson(pattern string, def ...interface{}) *gjson.Json {
 	return nil
 }
 
+// GetJsons gets the value by specified <pattern>,
+// and converts it to a slice of un-concurrent-safe Json object.
 func (c *Config) GetJsons(pattern string, def ...interface{}) []*gjson.Json {
 	if j := c.getJson(); j != nil {
 		return j.GetJsons(pattern, def...)
@@ -226,6 +280,8 @@ func (c *Config) GetJsons(pattern string, def ...interface{}) []*gjson.Json {
 	return nil
 }
 
+// GetJsonMap gets the value by specified <pattern>,
+// and converts it to a map of un-concurrent-safe Json object.
 func (c *Config) GetJsonMap(pattern string, def ...interface{}) map[string]*gjson.Json {
 	if j := c.getJson(); j != nil {
 		return j.GetJsonMap(pattern, def...)
@@ -233,6 +289,8 @@ func (c *Config) GetJsonMap(pattern string, def ...interface{}) map[string]*gjso
 	return nil
 }
 
+// GetStruct retrieves the value by specified <pattern> and converts it to specified object
+// <pointer>. The <pointer> should be the pointer to an object.
 func (c *Config) GetStruct(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetStruct(pattern, pointer, mapping...)
@@ -240,6 +298,7 @@ func (c *Config) GetStruct(pattern string, pointer interface{}, mapping ...map[s
 	return errors.New("configuration not found")
 }
 
+// GetStructDeep does GetStruct recursively.
 func (c *Config) GetStructDeep(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetStructDeep(pattern, pointer, mapping...)
@@ -247,6 +306,7 @@ func (c *Config) GetStructDeep(pattern string, pointer interface{}, mapping ...m
 	return errors.New("configuration not found")
 }
 
+// GetStructs converts any slice to given struct slice.
 func (c *Config) GetStructs(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetStructs(pattern, pointer, mapping...)
@@ -254,6 +314,7 @@ func (c *Config) GetStructs(pattern string, pointer interface{}, mapping ...map[
 	return errors.New("configuration not found")
 }
 
+// GetStructsDeep converts any slice to given struct slice recursively.
 func (c *Config) GetStructsDeep(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetStructsDeep(pattern, pointer, mapping...)
@@ -261,6 +322,8 @@ func (c *Config) GetStructsDeep(pattern string, pointer interface{}, mapping ...
 	return errors.New("configuration not found")
 }
 
+// GetMapToMap retrieves the value by specified <pattern> and converts it to specified map variable.
+// See gconv.MapToMap.
 func (c *Config) GetMapToMap(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetMapToMap(pattern, pointer, mapping...)
@@ -268,6 +331,9 @@ func (c *Config) GetMapToMap(pattern string, pointer interface{}, mapping ...map
 	return errors.New("configuration not found")
 }
 
+// GetMapToMapDeep retrieves the value by specified <pattern> and converts it to specified map
+// variable recursively.
+// See gconv.MapToMapDeep.
 func (c *Config) GetMapToMapDeep(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetMapToMapDeep(pattern, pointer, mapping...)
@@ -275,6 +341,9 @@ func (c *Config) GetMapToMapDeep(pattern string, pointer interface{}, mapping ..
 	return errors.New("configuration not found")
 }
 
+// GetMapToMaps retrieves the value by specified <pattern> and converts it to specified map slice
+// variable.
+// See gconv.MapToMaps.
 func (c *Config) GetMapToMaps(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetMapToMaps(pattern, pointer, mapping...)
@@ -282,6 +351,9 @@ func (c *Config) GetMapToMaps(pattern string, pointer interface{}, mapping ...ma
 	return errors.New("configuration not found")
 }
 
+// GetMapToMapsDeep retrieves the value by specified <pattern> and converts it to specified map slice
+// variable recursively.
+// See gconv.MapToMapsDeep.
 func (c *Config) GetMapToMapsDeep(pattern string, pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.GetMapToMapsDeep(pattern, pointer, mapping...)
@@ -289,6 +361,8 @@ func (c *Config) GetMapToMapsDeep(pattern string, pointer interface{}, mapping .
 	return errors.New("configuration not found")
 }
 
+// ToMap converts current Json object to map[string]interface{}.
+// It returns nil if fails.
 func (c *Config) ToMap() map[string]interface{} {
 	if j := c.getJson(); j != nil {
 		return j.ToMap()
@@ -296,6 +370,8 @@ func (c *Config) ToMap() map[string]interface{} {
 	return nil
 }
 
+// ToArray converts current Json object to []interface{}.
+// It returns nil if fails.
 func (c *Config) ToArray() []interface{} {
 	if j := c.getJson(); j != nil {
 		return j.ToArray()
@@ -303,6 +379,8 @@ func (c *Config) ToArray() []interface{} {
 	return nil
 }
 
+// ToStruct converts current Json object to specified object.
+// The <pointer> should be a pointer type of *struct.
 func (c *Config) ToStruct(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToStruct(pointer, mapping...)
@@ -310,6 +388,8 @@ func (c *Config) ToStruct(pointer interface{}, mapping ...map[string]string) err
 	return errors.New("configuration not found")
 }
 
+// ToStructDeep converts current Json object to specified object recursively.
+// The <pointer> should be a pointer type of *struct.
 func (c *Config) ToStructDeep(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToStructDeep(pointer, mapping...)
@@ -317,6 +397,8 @@ func (c *Config) ToStructDeep(pointer interface{}, mapping ...map[string]string)
 	return errors.New("configuration not found")
 }
 
+// ToStructs converts current Json object to specified object slice.
+// The <pointer> should be a pointer type of []struct/*struct.
 func (c *Config) ToStructs(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToStructs(pointer, mapping...)
@@ -324,6 +406,8 @@ func (c *Config) ToStructs(pointer interface{}, mapping ...map[string]string) er
 	return errors.New("configuration not found")
 }
 
+// ToStructsDeep converts current Json object to specified object slice recursively.
+// The <pointer> should be a pointer type of []struct/*struct.
 func (c *Config) ToStructsDeep(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToStructsDeep(pointer, mapping...)
@@ -331,6 +415,8 @@ func (c *Config) ToStructsDeep(pointer interface{}, mapping ...map[string]string
 	return errors.New("configuration not found")
 }
 
+// ToMapToMap converts current Json object to specified map variable.
+// The parameter of <pointer> should be type of *map.
 func (c *Config) ToMapToMap(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToMapToMap(pointer, mapping...)
@@ -338,6 +424,8 @@ func (c *Config) ToMapToMap(pointer interface{}, mapping ...map[string]string) e
 	return errors.New("configuration not found")
 }
 
+// ToMapToMapDeep converts current Json object to specified map variable recursively.
+// The parameter of <pointer> should be type of *map.
 func (c *Config) ToMapToMapDeep(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToMapToMapDeep(pointer, mapping...)
@@ -345,6 +433,8 @@ func (c *Config) ToMapToMapDeep(pointer interface{}, mapping ...map[string]strin
 	return errors.New("configuration not found")
 }
 
+// ToMapToMaps converts current Json object to specified map variable slice.
+// The parameter of <pointer> should be type of []map/*map.
 func (c *Config) ToMapToMaps(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToMapToMaps(pointer, mapping...)
@@ -352,6 +442,8 @@ func (c *Config) ToMapToMaps(pointer interface{}, mapping ...map[string]string)
 	return errors.New("configuration not found")
 }
 
+// ToMapToMapsDeep converts current Json object to specified map variable slice recursively.
+// The parameter of <pointer> should be type of []map/*map.
 func (c *Config) ToMapToMapsDeep(pointer interface{}, mapping ...map[string]string) error {
 	if j := c.getJson(); j != nil {
 		return j.ToMapToMapsDeep(pointer, mapping...)
diff --git a/os/gcfg/gcfg_z_unit_test.go b/os/gcfg/gcfg_z_unit_test.go
index 347cebcc8..2c81ca6a0 100644
--- a/os/gcfg/gcfg_z_unit_test.go
+++ b/os/gcfg/gcfg_z_unit_test.go
@@ -82,7 +82,6 @@ array = [1,2,3]
 			"cache": "127.0.0.1:6379,1",
 		})
 		t.AssertEQ(c.FilePath(), gfile.Pwd()+gfile.Separator+path)
-
 	})
 }
 
@@ -359,6 +358,23 @@ func TestCfg_FilePath(t *testing.T) {
 	})
 }
 
+func TestCfg_et(t *testing.T) {
+	config := `log-path = "logs"`
+	gtest.C(t, func(t *gtest.T) {
+		path := gcfg.DEFAULT_CONFIG_FILE
+		err := gfile.PutContents(path, config)
+		t.Assert(err, nil)
+		defer gfile.Remove(path)
+
+		c := gcfg.New()
+		t.Assert(c.Get("log-path"), "logs")
+
+		err = c.Set("log-path", "custom-logs")
+		t.Assert(err, nil)
+		t.Assert(c.Get("log-path"), "custom-logs")
+	})
+}
+
 func TestCfg_Get(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
 		var err error