Support process group ID (pgid) for Darwin and Linux (#26)

* Added Darwin pgid

* Added Linux pgid

* Skip the task_info test if not running as root

sigar_darwin.go

@@ -252,6 +252,8 @@ func (self *ProcState) Get(pid int) error {
 
 	self.Ppid = int(info.pbsd.pbi_ppid)
 
+	self.Pgid = int(info.pbsd.pbi_pgid)
+
 	self.Tty = int(info.pbsd.e_tdev)
 
 	self.Priority = int(info.ptinfo.pti_priority)

sigar_darwin_test.go

@@ -0,0 +1,76 @@
+package gosigar_test
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os/exec"
+	"os/user"
+	"strconv"
+	"strings"
+	"testing"
+
+	sigar "github.com/elastic/gosigar"
+	"github.com/stretchr/testify/assert"
+)
+
+var procinfo map[string]string
+
+func setUp(t testing.TB) {
+	out, err := exec.Command("/bin/ps", "-p1", "-c", "-opid,comm,stat,ppid,pgid,tty,pri,ni").Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+	rdr := bufio.NewReader(bytes.NewReader(out))
+	_, err = rdr.ReadString('\n') // skip header
+	if err != nil {
+		t.Fatal(err)
+	}
+	data, err := rdr.ReadString('\n')
+	if err != nil {
+		t.Fatal(err)
+	}
+	procinfo = make(map[string]string, 8)
+	fields := strings.Fields(data)
+	procinfo["pid"] = fields[0]
+	procinfo["name"] = fields[1]
+	procinfo["stat"] = fields[2]
+	procinfo["ppid"] = fields[3]
+	procinfo["pgid"] = fields[4]
+	procinfo["tty"] = fields[5]
+	procinfo["prio"] = fields[6]
+	procinfo["nice"] = fields[7]
+
+}
+
+func tearDown(t testing.TB) {
+}
+
+/* ProcState.Get() call task_info, which on Mac OS X requires root
+   or a signed executable. Skip the test if not running as root
+   to accommodate automated tests, but let users test locally using
+   `sudo -E go test`
+*/
+
+func TestDarwinProcState(t *testing.T) {
+	setUp(t)
+	defer tearDown(t)
+
+	state := sigar.ProcState{}
+	usr, err := user.Current()
+	if err == nil && usr.Username == "root" {
+		if assert.NoError(t, state.Get(1)) {
+
+			ppid, _ := strconv.Atoi(procinfo["ppid"])
+			pgid, _ := strconv.Atoi(procinfo["pgid"])
+
+			assert.Equal(t, procinfo["name"], state.Name)
+			assert.Equal(t, ppid, state.Ppid)
+			assert.Equal(t, pgid, state.Pgid)
+			assert.Equal(t, 1, state.Pgid)
+			assert.Equal(t, 0, state.Ppid)
+		}
+	} else {
+		fmt.Println("Skipping ProcState test; run as root to test")
+	}
+}

sigar_interface.go

@@ -109,6 +109,7 @@ type ProcState struct {
 	Username  string
 	State     RunState
 	Ppid      int
+	Pgid      int
 	Tty       int
 	Priority  int
 	Nice      int

sigar_linux.go

@@ -212,6 +212,8 @@ func (self *ProcState) Get(pid int) error {
 
 	self.Ppid, _ = strconv.Atoi(fields[1])
 
+	self.Pgid, _ = strconv.Atoi(fields[2])
+
 	self.Tty, _ = strconv.Atoi(fields[4])
 
 	self.Priority, _ = strconv.Atoi(fields[15])

sigar_linux_test.go

@@ -67,6 +67,7 @@ func TestLinuxProcState(t *testing.T) {
 			state := sigar.ProcState{}
 			if assert.NoError(t, state.Get(pid)) {
 				assert.Equal(t, n, state.Name)
+				assert.Equal(t, 2, state.Pgid)
 				assert.Equal(t, strconv.Itoa(uid), state.Username)
 			}
 		}()
@@ -218,9 +219,9 @@ DirectMap2M:      333824 kB
 }
 
 func writePidStats(pid int, procName string, path string) error {
-	stats := "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 " +
+	stats := "S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 " +
 		"20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 " +
-		"35 36 37 38 39 40"
+		"35 36 37 38 39"
 
 	statContents := []byte(fmt.Sprintf("%d (%s) %s", pid, procName, stats))
 	return ioutil.WriteFile(path, statContents, 0644)