diff --git a/os/gfile/gfile_home.go b/os/gfile/gfile_home.go
index f75de43fe..68bc6c645 100644
--- a/os/gfile/gfile_home.go
+++ b/os/gfile/gfile_home.go
@@ -38,7 +38,7 @@ func getHomePath() (string, error) {
 	if nil == err {
 		return u.HomeDir, nil
 	}
-	if "windows" == runtime.GOOS {
+	if runtime.GOOS == "windows" {
 		return homeWindows()
 	}
 	return homeUnix()
diff --git a/os/gfile/gfile_z_example_cache_test.go b/os/gfile/gfile_z_example_cache_test.go
new file mode 100644
index 000000000..3ca819779
--- /dev/null
+++ b/os/gfile/gfile_z_example_cache_test.go
@@ -0,0 +1,43 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleGetContentsWithCache() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_cache")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// It reads the file content with cache duration of one minute,
+	// which means it reads from cache after then without any IO operations within on minute.
+	fmt.Println(gfile.GetContentsWithCache(tempFile, time.Minute))
+
+	// write new contents will clear its cache
+	gfile.PutContents(tempFile, "new goframe example content")
+
+	// There's some delay for cache clearing after file content change.
+	time.Sleep(time.Second * 1)
+
+	// read contents
+	fmt.Println(gfile.GetContentsWithCache(tempFile))
+
+	// May Output:
+	// goframe example content
+	// new goframe example content
+}
diff --git a/os/gfile/gfile_z_example_contents_test.go b/os/gfile/gfile_z_example_contents_test.go
new file mode 100644
index 000000000..13e90500c
--- /dev/null
+++ b/os/gfile/gfile_z_example_contents_test.go
@@ -0,0 +1,240 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleGetContents() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// It reads and returns the file content as string.
+	// It returns empty string if it fails reading, for example, with permission or IO error.
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+}
+
+func ExampleGetBytes() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// It reads and returns the file content as []byte.
+	// It returns nil if it fails reading, for example, with permission or IO error.
+	fmt.Println(gfile.GetBytes(tempFile))
+
+	// Output:
+	// [103 111 102 114 97 109 101 32 101 120 97 109 112 108 101 32 99 111 110 116 101 110 116]
+}
+
+func ExamplePutContents() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// It creates and puts content string into specifies file path.
+	// It automatically creates directory recursively if it does not exist.
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+}
+
+func ExamplePutBytes() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutBytes(tempFile, []byte("goframe example content"))
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+}
+
+func ExamplePutContentsAppend() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// It creates and append content string into specifies file path.
+	// It automatically creates directory recursively if it does not exist.
+	gfile.PutContentsAppend(tempFile, " append content")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+	// goframe example content append content
+}
+
+func ExamplePutBytesAppend() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// write contents
+	gfile.PutBytesAppend(tempFile, []byte(" append"))
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+	// goframe example content append
+}
+
+func ExampleGetNextCharOffsetByPath() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	index := gfile.GetNextCharOffsetByPath(tempFile, 'f', 0)
+	fmt.Println(index)
+
+	// Output:
+	// 2
+}
+
+func ExampleGetBytesTilCharByPath() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetBytesTilCharByPath(tempFile, 'f', 0))
+
+	// Output:
+	// [103 111 102] 2
+}
+
+func ExampleGetBytesByTwoOffsetsByPath() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetBytesByTwoOffsetsByPath(tempFile, 0, 7))
+
+	// Output:
+	// [103 111 102 114 97 109 101]
+}
+
+func ExampleReadLines() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "L1 goframe example content\nL2 goframe example content")
+
+	// read contents
+	gfile.ReadLines(tempFile, func(text string) error {
+		// Process each line
+		fmt.Println(text)
+		return nil
+	})
+
+	// Output:
+	// L1 goframe example content
+	// L2 goframe example content
+}
+
+func ExampleReadLinesBytes() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_content")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "L1 goframe example content\nL2 goframe example content")
+
+	// read contents
+	gfile.ReadLinesBytes(tempFile, func(bytes []byte) error {
+		// Process each line
+		fmt.Println(bytes)
+		return nil
+	})
+
+	// Output:
+	// [76 49 32 103 111 102 114 97 109 101 32 101 120 97 109 112 108 101 32 99 111 110 116 101 110 116]
+	// [76 50 32 103 111 102 114 97 109 101 32 101 120 97 109 112 108 101 32 99 111 110 116 101 110 116]
+}
diff --git a/os/gfile/gfile_z_example_copy_test.go b/os/gfile/gfile_z_example_copy_test.go
new file mode 100644
index 000000000..293d40a82
--- /dev/null
+++ b/os/gfile/gfile_z_example_copy_test.go
@@ -0,0 +1,52 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleCopy() {
+	// init
+	var (
+		srcFileName = "gflie_example.txt"
+		srcTempDir  = gfile.TempDir("gfile_example_copy_src")
+		srcTempFile = gfile.Join(srcTempDir, srcFileName)
+
+		// copy file
+		dstFileName = "gflie_example_copy.txt"
+		dstTempFile = gfile.Join(srcTempDir, dstFileName)
+
+		// copy dir
+		dstTempDir = gfile.TempDir("gfile_example_copy_dst")
+	)
+
+	// write contents
+	gfile.PutContents(srcTempFile, "goframe example copy")
+
+	// copy file
+	gfile.Copy(srcTempFile, dstTempFile)
+
+	// read contents after copy file
+	fmt.Println(gfile.GetContents(dstTempFile))
+
+	// copy dir
+	gfile.Copy(srcTempDir, dstTempDir)
+
+	// list copy dir file
+	fList, _ := gfile.ScanDir(dstTempDir, "*", false)
+	for _, v := range fList {
+		fmt.Println(gfile.Basename(v))
+	}
+
+	// Output:
+	// goframe example copy
+	// gflie_example.txt
+	// gflie_example_copy.txt
+}
diff --git a/os/gfile/gfile_z_example_home_test.go b/os/gfile/gfile_z_example_home_test.go
new file mode 100644
index 000000000..9cc2b9707
--- /dev/null
+++ b/os/gfile/gfile_z_example_home_test.go
@@ -0,0 +1,22 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleHome() {
+	// user's home directory
+	homePath, _ := gfile.Home()
+	fmt.Println(homePath)
+
+	// May Output:
+	// C:\Users\hailaz
+}
diff --git a/os/gfile/gfile_z_example_replace_test.go b/os/gfile/gfile_z_example_replace_test.go
new file mode 100644
index 000000000..df4d3a931
--- /dev/null
+++ b/os/gfile/gfile_z_example_replace_test.go
@@ -0,0 +1,120 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+	"regexp"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleReplaceFile() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_replace")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// It replaces content directly by file path.
+	gfile.ReplaceFile("content", "replace word", tempFile)
+
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+	// goframe example replace word
+}
+
+func ExampleReplaceFileFunc() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_replace")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example 123")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// It replaces content directly by file path and callback function.
+	gfile.ReplaceFileFunc(func(path, content string) string {
+		// Replace with regular match
+		reg, _ := regexp.Compile(`\d{3}`)
+		return reg.ReplaceAllString(content, "[num]")
+	}, tempFile)
+
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example 123
+	// goframe example [num]
+}
+
+func ExampleReplaceDir() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_replace")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// It replaces content of all files under specified directory recursively.
+	gfile.ReplaceDir("content", "replace word", tempDir, "gflie_example.txt", true)
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example content
+	// goframe example replace word
+}
+
+func ExampleReplaceDirFunc() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_replace")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example 123")
+
+	// read contents
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// It replaces content of all files under specified directory with custom callback function recursively.
+	gfile.ReplaceDirFunc(func(path, content string) string {
+		// Replace with regular match
+		reg, _ := regexp.Compile(`\d{3}`)
+		return reg.ReplaceAllString(content, "[num]")
+	}, tempDir, "gflie_example.txt", true)
+
+	fmt.Println(gfile.GetContents(tempFile))
+
+	// Output:
+	// goframe example 123
+	// goframe example [num]
+
+}
diff --git a/os/gfile/gfile_z_example_scan_test.go b/os/gfile/gfile_z_example_scan_test.go
new file mode 100644
index 000000000..0238dbbb0
--- /dev/null
+++ b/os/gfile/gfile_z_example_scan_test.go
@@ -0,0 +1,133 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleScanDir() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_scan_dir")
+		tempFile = gfile.Join(tempDir, fileName)
+
+		tempSubDir  = gfile.Join(tempDir, "sub_dir")
+		tempSubFile = gfile.Join(tempSubDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+	gfile.PutContents(tempSubFile, "goframe example content")
+
+	// scans directory recursively
+	list, _ := gfile.ScanDir(tempDir, "*", true)
+	for _, v := range list {
+		fmt.Println(gfile.Basename(v))
+	}
+
+	// Output:
+	// gflie_example.txt
+	// sub_dir
+	// gflie_example.txt
+}
+
+func ExampleScanDirFile() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_scan_dir_file")
+		tempFile = gfile.Join(tempDir, fileName)
+
+		tempSubDir  = gfile.Join(tempDir, "sub_dir")
+		tempSubFile = gfile.Join(tempSubDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+	gfile.PutContents(tempSubFile, "goframe example content")
+
+	// scans directory recursively exclusive of directories
+	list, _ := gfile.ScanDirFile(tempDir, "*.txt", true)
+	for _, v := range list {
+		fmt.Println(gfile.Basename(v))
+	}
+
+	// Output:
+	// gflie_example.txt
+	// gflie_example.txt
+}
+
+func ExampleScanDirFunc() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_scan_dir_func")
+		tempFile = gfile.Join(tempDir, fileName)
+
+		tempSubDir  = gfile.Join(tempDir, "sub_dir")
+		tempSubFile = gfile.Join(tempSubDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+	gfile.PutContents(tempSubFile, "goframe example content")
+
+	// scans directory recursively
+	list, _ := gfile.ScanDirFunc(tempDir, "*", true, func(path string) string {
+		// ignores some files
+		if gfile.Basename(path) == "gflie_example.txt" {
+			return ""
+		}
+		return path
+	})
+	for _, v := range list {
+		fmt.Println(gfile.Basename(v))
+	}
+
+	// Output:
+	// sub_dir
+}
+
+func ExampleScanDirFileFunc() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_scan_dir_file_func")
+		tempFile = gfile.Join(tempDir, fileName)
+
+		fileName1 = "gflie_example_ignores.txt"
+		tempFile1 = gfile.Join(tempDir, fileName1)
+
+		tempSubDir  = gfile.Join(tempDir, "sub_dir")
+		tempSubFile = gfile.Join(tempSubDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+	gfile.PutContents(tempFile1, "goframe example content")
+	gfile.PutContents(tempSubFile, "goframe example content")
+
+	// scans directory recursively exclusive of directories
+	list, _ := gfile.ScanDirFileFunc(tempDir, "*.txt", true, func(path string) string {
+		// ignores some files
+		if gfile.Basename(path) == "gflie_example_ignores.txt" {
+			return ""
+		}
+		return path
+	})
+	for _, v := range list {
+		fmt.Println(gfile.Basename(v))
+	}
+
+	// Output:
+	// gflie_example.txt
+	// gflie_example.txt
+}
diff --git a/os/gfile/gfile_z_example_search_test.go b/os/gfile/gfile_z_example_search_test.go
new file mode 100644
index 000000000..3fdaf4309
--- /dev/null
+++ b/os/gfile/gfile_z_example_search_test.go
@@ -0,0 +1,32 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleSearch() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_search")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "goframe example content")
+
+	// search file
+	realPath, _ := gfile.Search(fileName, tempDir)
+	fmt.Println(gfile.Basename(realPath))
+
+	// Output:
+	// gflie_example.txt
+}
diff --git a/os/gfile/gfile_z_example_size_test.go b/os/gfile/gfile_z_example_size_test.go
new file mode 100644
index 000000000..b4696e6bc
--- /dev/null
+++ b/os/gfile/gfile_z_example_size_test.go
@@ -0,0 +1,83 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleSize() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_size")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "0123456789")
+	fmt.Println(gfile.Size(tempFile))
+
+	// Output:
+	// 10
+}
+
+func ExampleSizeFormat() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_size")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "0123456789")
+	fmt.Println(gfile.SizeFormat(tempFile))
+
+	// Output:
+	// 10.00B
+}
+
+func ExampleReadableSize() {
+	// init
+	var (
+		fileName = "gflie_example.txt"
+		tempDir  = gfile.TempDir("gfile_example_size")
+		tempFile = gfile.Join(tempDir, fileName)
+	)
+
+	// write contents
+	gfile.PutContents(tempFile, "01234567899876543210")
+	fmt.Println(gfile.ReadableSize(tempFile))
+
+	// Output:
+	// 20.00B
+}
+
+func ExampleStrToSize() {
+	size := gfile.StrToSize("100MB")
+	fmt.Println(size)
+
+	// Output:
+	// 104857600
+}
+
+func ExampleFormatSize() {
+	sizeStr := gfile.FormatSize(104857600)
+	fmt.Println(sizeStr)
+	sizeStr0 := gfile.FormatSize(1024)
+	fmt.Println(sizeStr0)
+	sizeStr1 := gfile.FormatSize(999999999999999999)
+	fmt.Println(sizeStr1)
+
+	// Output:
+	// 100.00M
+	// 1.00K
+	// 888.18P
+}
diff --git a/os/gfile/gfile_z_example_sort_test.go b/os/gfile/gfile_z_example_sort_test.go
new file mode 100644
index 000000000..aaa46d2b6
--- /dev/null
+++ b/os/gfile/gfile_z_example_sort_test.go
@@ -0,0 +1,32 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleSortFiles() {
+	files := []string{
+		"/aaa/bbb/ccc.txt",
+		"/aaa/bbb/",
+		"/aaa/",
+		"/aaa",
+		"/aaa/ccc/ddd.txt",
+		"/bbb",
+		"/0123",
+		"/ddd",
+		"/ccc",
+	}
+	sortOut := gfile.SortFiles(files)
+	fmt.Println(sortOut)
+
+	// Output:
+	// [/0123 /aaa /aaa/ /aaa/bbb/ /aaa/bbb/ccc.txt /aaa/ccc/ddd.txt /bbb /ccc /ddd]
+}
diff --git a/os/gfile/gfile_z_example_time_test.go b/os/gfile/gfile_z_example_time_test.go
new file mode 100644
index 000000000..e4a11ef51
--- /dev/null
+++ b/os/gfile/gfile_z_example_time_test.go
@@ -0,0 +1,37 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gfile_test
+
+import (
+	"fmt"
+
+	"github.com/gogf/gf/v2/os/gfile"
+)
+
+func ExampleMTime() {
+	t := gfile.MTime(gfile.TempDir())
+	fmt.Println(t)
+
+	// May Output:
+	// 2021-11-02 15:18:43.901141 +0800 CST
+}
+
+func ExampleMTimestamp() {
+	t := gfile.MTimestamp(gfile.TempDir())
+	fmt.Println(t)
+
+	// May Output:
+	// 1635838398
+}
+
+func ExampleMTimestampMilli() {
+	t := gfile.MTimestampMilli(gfile.TempDir())
+	fmt.Println(t)
+
+	// May Output:
+	// 1635838529330
+}
diff --git a/os/gfile/gfile_z_unit_contents_test.go b/os/gfile/gfile_z_unit_contents_test.go
index bd972d523..3d38e18a6 100644
--- a/os/gfile/gfile_z_unit_contents_test.go
+++ b/os/gfile/gfile_z_unit_contents_test.go
@@ -103,8 +103,8 @@ func Test_Truncate(t *testing.T) {
 		t.Assert(err, nil)
 
 		files, err = os.Open(testpath() + filepaths1)
-		defer files.Close()
 		t.Assert(err, nil)
+		defer files.Close()
 		fileinfo, err2 := files.Stat()
 		t.Assert(err2, nil)
 		t.Assert(fileinfo.Size(), 10)
diff --git a/os/gfile/gfile_z_unit_test.go b/os/gfile/gfile_z_unit_test.go
index 60d7bf7ba..4ef155e26 100644
--- a/os/gfile/gfile_z_unit_test.go
+++ b/os/gfile/gfile_z_unit_test.go
@@ -190,7 +190,7 @@ func Test_OpenWithFlagPerm(t *testing.T) {
 		flags = append(flags, false)
 
 		for k, v := range files {
-			fileobj, err = gfile.OpenWithFlagPerm(testpath()+v, os.O_RDWR, 666)
+			fileobj, err = gfile.OpenWithFlagPerm(testpath()+v, os.O_RDWR, 0666)
 			fileobj.Close()
 			if flags[k] {
 				t.Assert(err, nil)