enable gosimple linter

.golangci.yml

@@ -2,7 +2,6 @@ linters:
   disable:
     - deadcode
     - errcheck
-    - gosimple
     - govet
     - ineffassign
     - staticcheck

v3/cpu/cpu_linux.go

@@ -240,7 +240,7 @@ func parseStatLine(line string) (*TimesStat, error) {
 		return nil, errors.New("stat does not contain cpu info")
 	}
 
-	if strings.HasPrefix(fields[0], "cpu") == false {
+	if !strings.HasPrefix(fields[0], "cpu") {
 		return nil, errors.New("not contain cpu")
 	}
 

v3/disk/disk_linux.go

@@ -349,7 +349,7 @@ func IOCountersWithContext(ctx context.Context, names ...string) (map[string]IOC
 	if err != nil {
 		return nil, err
 	}
-	ret := make(map[string]IOCountersStat, 0)
+	ret := make(map[string]IOCountersStat)
 	empty := IOCountersStat{}
 
 	// use only basename such as "/dev/sda1" to "sda1"

v3/internal/common/common_unix.go

@@ -41,8 +41,7 @@ func CallLsofWithContext(ctx context.Context, invoke Invoker, pid int32, args ..
 }
 
 func CallPgrepWithContext(ctx context.Context, invoke Invoker, pid int32) ([]int32, error) {
-	var cmd []string
+	cmd := []string{"-P", strconv.Itoa(int(pid))}
-	cmd = []string{"-P", strconv.Itoa(int(pid))}
 	pgrep, err := exec.LookPath("pgrep")
 	if err != nil {
 		return []int32{}, err

v3/net/net.go

@@ -131,7 +131,7 @@ func (l *ConntrackStatList) Append(c *ConntrackStat) {
 }
 
 func (l *ConntrackStatList) Items() []ConntrackStat {
-	items := make([]ConntrackStat, len(l.items), len(l.items))
+	items := make([]ConntrackStat, len(l.items))
 	for i, el := range l.items {
 		items[i] = *el
 	}

v3/net/net_linux.go

@@ -140,7 +140,7 @@ func IOCountersByFileWithContext(ctx context.Context, pernic bool, filename stri
 		ret = append(ret, nic)
 	}
 
-	if pernic == false {
+	if !pernic {
 		return getIOCountersAll(ret)
 	}
 

v3/process/process_linux.go

@@ -726,10 +726,7 @@ func (p *Process) fillFromIOWithContext(ctx context.Context) (*IOCountersStat, e
 		if err != nil {
 			return nil, err
 		}
-		param := field[0]
+		param := strings.TrimSuffix(field[0], ":")
-		if strings.HasSuffix(param, ":") {
-			param = param[:len(param)-1]
-		}
 		switch param {
 		case "syscr":
 			ret.ReadCount = t