Parses the tgid field, which is the thread group id (aka user-space process id) on Linux. Returns error on other platforms.

process/process.go

@@ -30,6 +30,8 @@ type Process struct {
 
 	lastCPUTimes *cpu.TimesStat
 	lastCPUTime  time.Time
+
+	tgid int32
 }
 
 type OpenFilesStat struct {

process/process_fallback.go

@@ -41,6 +41,9 @@ func (p *Process) Ppid() (int32, error) {
 func (p *Process) Name() (string, error) {
 	return "", common.ErrNotImplementedError
 }
+func (p *Process) Tgid() (int32, error) {
+	return 0, common.ErrNotImplementedError
+}
 func (p *Process) Exe() (string, error) {
 	return "", common.ErrNotImplementedError
 }

process/process_linux.go

@@ -100,6 +100,16 @@ func (p *Process) Name() (string, error) {
 	return p.name, nil
 }
 
+// Tgid returns tgid, a Linux-synonym for user-space Pid
+func (p *Process) Tgid() (int32, error) {
+	if p.tgid == 0 {
+		if err := p.fillFromStatus(); err != nil {
+			return 0, err
+		}
+	}
+	return p.tgid, nil
+}
+
 // Exe returns executable path of the process.
 func (p *Process) Exe() (string, error) {
 	return p.fillFromExe()
@@ -820,6 +830,12 @@ func (p *Process) fillFromStatus() error {
 				return err
 			}
 			p.parent = int32(pval)
+		case "Tgid":
+			pval, err := strconv.ParseInt(value, 10, 32)
+			if err != nil {
+				return err
+			}
+			p.tgid = int32(pval)
 		case "Uid":
 			p.uids = make([]int32, 0, 4)
 			for _, i := range strings.Split(value, "\t") {