ReadEnv() minor improvement

 - Improved peformance parsing the environment variables of a process.
 - Added ReadEnv() test.

For a 4kb environ file:

Benchmark-Old    58070 ns/op   19264 B/op   68 allocs/op
Benchmark-New    49174 ns/op   17488 B/op   12 allocs/op

daemon/procmon/details.go

@@ -168,19 +168,23 @@ func (p *Process) ReadCwd() error {
 
 // ReadEnv reads and parses the environment variables of a process.
 func (p *Process) ReadEnv() {
-	data, err := ioutil.ReadFile(p.pathEnviron)
+	raw, err := ioutil.ReadFile(p.pathEnviron)
 	if err != nil {
 		return
 	}
-	for _, s := range strings.Split(string(data), "\x00") {
-		parts := strings.SplitN(core.Trim(s), "=", 2)
-		if parts != nil && len(parts) == 2 {
-			key := core.Trim(parts[0])
-			val := core.Trim(parts[1])
-			p.mu.Lock()
-			p.Env[key] = val
-			p.mu.Unlock()
+	raw = bytes.Trim(raw, "\r\n\t")
+	vars := strings.Split(string(raw), "\x00")
+	for _, s := range vars {
+		idx := strings.Index(s, "=")
+		if idx == -1 {
+			continue
 		}
+
+		key := s[:idx]
+		val := s[idx+1 : len(s)]
+		p.mu.Lock()
+		p.Env[key] = val
+		p.mu.Unlock()
 	}
 }
 

daemon/procmon/process_test.go

@@ -53,11 +53,31 @@ func TestProcDescriptors(t *testing.T) {
 }
 
 func TestProcEnv(t *testing.T) {
+	proc.pathEnviron = "testdata/proc-environ"
 	proc.ReadEnv()
 
-	if len(proc.Env) == 0 {
-		t.Error("Proc Env should not be empty:", proc.Env)
+	expected := map[string]string{
+		"EMPTY":                    "",
+		"TEST1":                    "xxx=123",
+		"TEST2":                    "xxx=123==456",
+		"SSH_AGENT_PID":            "4873",
+		"XDG_CURRENT_DESKTOP":      "i3",
+		"USER":                     "opensnitch",
+		"HOME":                     "/tmp",
+		"XDG_DATA_DIRS":            "/usr/share/gnome:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share",
+		"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1000/bus",
+		// Test latest var
+		"LS_COLORS": "rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;",
+
+		//"LAST":      "",
+	}
+
+	for k, v := range expected {
+		if env, found := proc.Env[k]; !found || env != v {
+			t.Error("Proc Env error, expected", ":", v, "got:", env, "(", k, ")")
+		}
 	}
+
 }
 
 func TestProcIOStats(t *testing.T) {
@@ -113,3 +133,9 @@ func TestProcCleanPath(t *testing.T) {
 		t.Error("Proc cleanPath() not cleaned:", proc.Path)
 	}
 }
+
+func BenchmarkProcReadEnv(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		proc.ReadEnv()
+	}
+}