diff --git a/flag/flag_type.go b/flag/flag_type.go
new file mode 100644
index 0000000..103f491
--- /dev/null
+++ b/flag/flag_type.go
@@ -0,0 +1,22 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"time"
+)
+
+// flag获取命令行参数
+func main() {
+	//创建一个标志位参数
+	name := flag.String("name", "wangao", "define name")
+	age := flag.Int("age", 9000, "define age")
+	married := flag.Bool("married", false, "define married")
+	mTime := flag.Duration("mtime", time.Second, "define mTime") //命令行接受的参数需要带单位，例如1000h:main.exe -mtime 1000h
+	//使用flag
+	flag.Parse()
+	fmt.Println(*name, *age, *married, mTime)
+	fmt.Println(flag.Args())  //返回命令行参数后的其他参数，以[]string类型返回
+	fmt.Println(flag.NArg())  // 返回命令行的其他参数个数
+	fmt.Println(flag.NFlag()) //返回使用的命令行参数个数
+}
diff --git a/flag/flag_typevar.go b/flag/flag_typevar.go
new file mode 100644
index 0000000..5b3172b
--- /dev/null
+++ b/flag/flag_typevar.go
@@ -0,0 +1,14 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+)
+
+func main() {
+	var name string
+	flag.StringVar(&name, "name", "wangao", "define name")
+	flag.Parse()
+	fmt.Println(name)
+
+}
diff --git a/flag/os.args.go b/flag/os.args.go
new file mode 100644
index 0000000..943d9f7
--- /dev/null
+++ b/flag/os.args.go
@@ -0,0 +1,11 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+// os.Args 获取命令行参数
+func main() {
+	fmt.Printf("%#v", os.Args) //获取当前的执行文件和参数
+}
diff --git a/networkProgram/TCP/packet_splicing_client.go b/networkProgram/TCP/packet_splicing_client.go
index ce6dad1..374e011 100644
--- a/networkProgram/TCP/packet_splicing_client.go
+++ b/networkProgram/TCP/packet_splicing_client.go
@@ -7,7 +7,7 @@ import (
 	"course/networkProgram/protocol"
 )
 
-// socket_stick/client/main.go
+// socket_stick/client/os.args.go
 
 func main() {
 	conn, err := net.Dial("tcp", "127.0.0.1:30000")
diff --git a/networkProgram/TCP/packet_splicing_server.go b/networkProgram/TCP/packet_splicing_server.go
index 54656fc..ce9cff5 100644
--- a/networkProgram/TCP/packet_splicing_server.go
+++ b/networkProgram/TCP/packet_splicing_server.go
@@ -8,7 +8,7 @@ import (
 	"net"
 )
 
-// socket_stick/server/main.go
+// socket_stick/server/os.args.go
 func proc(conn net.Conn) {
 	defer conn.Close()
 	reader := bufio.NewReader(conn)
diff --git a/pprof/pprof.go b/pprof/pprof.go
new file mode 100644
index 0000000..91eae0c
--- /dev/null
+++ b/pprof/pprof.go
@@ -0,0 +1,55 @@
+// runtime_pprof/os.args.go
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime/pprof"
+	"time"
+)
+
+// 一段有问题的代码
+func logicCode() {
+	var c chan int //nil 未初始化
+	for {
+		select {
+		case v := <-c: //阻塞
+			fmt.Printf("recv from chan, value:%v\n", v)
+		default:
+
+		}
+	}
+}
+
+func main() {
+	var isCPUPprof bool
+	var isMemPprof bool
+
+	flag.BoolVar(&isCPUPprof, "cpu", false, "turn cpu pprof on")
+	flag.BoolVar(&isMemPprof, "mem", false, "turn mem pprof on")
+	flag.Parse()
+
+	if isCPUPprof {
+		file, err := os.Create("./cpu.pprof")
+		if err != nil {
+			fmt.Printf("create cpu pprof failed, err:%v\n", err)
+			return
+		}
+		pprof.StartCPUProfile(file)
+		defer pprof.StopCPUProfile()
+	}
+	for i := 0; i < 8; i++ {
+		go logicCode()
+	}
+	time.Sleep(20 * time.Second)
+	if isMemPprof {
+		file, err := os.Create("./mem.pprof")
+		if err != nil {
+			fmt.Printf("create mem pprof failed, err:%v\n", err)
+			return
+		}
+		pprof.WriteHeapProfile(file)
+		file.Close()
+	}
+}
diff --git a/test/group_spilt_string_test.go b/test/group_spilt_string_test.go
new file mode 100644
index 0000000..0dea5a2
--- /dev/null
+++ b/test/group_spilt_string_test.go
@@ -0,0 +1,27 @@
+package Splitstring
+
+import (
+	"reflect"
+	"testing"
+)
+
+//测试组
+
+func TestGroupSplit(t *testing.T) {
+	type testCase struct {
+		str  string
+		sep  string
+		want []string
+	}
+	testGroup := []testCase{
+		{str: "babcbef", sep: "b", want: []string{"", "a", "c", "ef"}},
+		{str: "a:b:c", sep: ":", want: []string{"a", "b", "c"}},
+		{str: "abcef", sep: "bc", want: []string{"a", "ef"}},
+		{str: "沙河有沙又有河", sep: "有", want: []string{"沙河", "沙又", "河"}},
+	}
+	for i, testcase := range testGroup {
+		if !reflect.DeepEqual(Split(testcase.str, testcase.sep), testcase.want) {
+			t.Errorf("testcase %d failed,want: %v got: %v", i+1, testcase.want, Split(testcase.str, testcase.sep))
+		}
+	}
+}
diff --git a/test/groupchild_spilt_string_test.go b/test/groupchild_spilt_string_test.go
new file mode 100644
index 0000000..c71df2a
--- /dev/null
+++ b/test/groupchild_spilt_string_test.go
@@ -0,0 +1,30 @@
+package Splitstring
+
+import (
+	"reflect"
+	"testing"
+)
+
+//子测试
+
+func TestGroupChildSplit(t *testing.T) {
+	type testCase struct {
+		str  string
+		sep  string
+		want []string
+	}
+	testGroup := map[string]testCase{
+		"case1": {str: "babcbef", sep: "b", want: []string{"", "a", "c", "ef"}},
+		"case2": {str: "a:b:c", sep: ":", want: []string{"a", "b", "c"}},
+		"case3": {str: "abcef", sep: "bc", want: []string{"a", "ef"}},
+		"case4": {str: "沙河有沙又有河", sep: "有", want: []string{"沙河", "沙又", "河"}},
+	}
+	for name, testcase := range testGroup {
+		t.Run(name, func(t *testing.T) {
+			got := Split(testcase.str, testcase.sep)
+			if !reflect.DeepEqual(got, testcase.want) {
+				t.Errorf("got:%v, want:%v", got, testcase.want)
+			}
+		})
+	}
+}
diff --git a/test/spilt_string.go b/test/spilt_string.go
index e6acb35..45748b5 100644
--- a/test/spilt_string.go
+++ b/test/spilt_string.go
@@ -1,6 +1,8 @@
 package Splitstring
 
-import "strings"
+import (
+	"strings"
+)
 
 //切割字符串
 //example
@@ -21,11 +23,11 @@ import "strings"
 // abc,b =>[a,c]
 
 func Split(str string, sep string) []string {
-	ret := make([]string, 0)
+	var ret = make([]string, 0, strings.Count(str, sep)+1)
 	index := strings.Index(str, sep)
 	for index >= 0 {
 		ret = append(ret, str[:index])
-		str = str[index+1:]
+		str = str[index+len(sep):]
 		index = strings.Index(str, sep)
 	}
 	ret = append(ret, str)
diff --git a/test/spilt_string_test.go b/test/spilt_string_test.go
index 98947d5..852adaf 100644
--- a/test/spilt_string_test.go
+++ b/test/spilt_string_test.go
@@ -22,3 +22,19 @@ func TestSplit2(t *testing.T) {
 		t.Errorf("want:%v, but got:%v\n", want, got)
 	}
 }
+
+func TestSplit3(t *testing.T) {
+	got := Split("abcef", "bc")
+	want := []string{"a", "ef"}
+	if !reflect.DeepEqual(want, got) {
+		t.Fatalf("want:%v, but got:%v\n", want, got)
+	}
+}
+
+//基准测试
+
+func BenchmarkSplit(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Split("a:b:c:d:e:f", ":")
+	}
+}