Added limit constants. Implemented function to parse process limits from /proc.

process/process.go

@@ -60,6 +60,25 @@ type NumCtxSwitchesStat struct {
 	Involuntary int64 `json:"involuntary"`
 }
 
+const (
+	RLIMIT_CPU        int32 = 0
+	RLIMIT_FSIZE      int32 = 1
+	RLIMIT_DATA       int32 = 2
+	RLIMIT_STACK      int32 = 3
+	RLIMIT_CORE       int32 = 4
+	RLIMIT_RSS        int32 = 5
+	RLIMIT_NPROC      int32 = 6
+	RLIMIT_NOFILE     int32 = 7
+	RLIMIT_MEMLOCK    int32 = 8
+	RLIMIT_AS         int32 = 9
+	RLIMIT_LOCKS      int32 = 10
+	RLIMIT_SIGPENDING int32 = 11
+	RLIMIT_MSGQUEUE   int32 = 12
+	RLIMIT_NICE       int32 = 13
+	RLIMIT_RTPRIO     int32 = 14
+	RLIMIT_RTTIME     int32 = 15
+)
+
 func (p Process) String() string {
 	s, _ := json.Marshal(p)
 	return string(s)

process/process_linux.go

@@ -14,10 +14,12 @@ import (
 	"strings"
 	"syscall"
 
+	"bufio"
 	"github.com/shirou/gopsutil/cpu"
 	"github.com/shirou/gopsutil/host"
 	"github.com/shirou/gopsutil/internal/common"
 	"github.com/shirou/gopsutil/net"
+	"math"
 )
 
 var (
@@ -198,7 +200,7 @@ func (p *Process) IOnice() (int32, error) {
 
 // Rlimit returns Resource Limits.
 func (p *Process) Rlimit() ([]RlimitStat, error) {
-	return nil, common.ErrNotImplementedError
+	return p.fillFromLimits()
 }
 
 // IOCounters returns IO Counters.
@@ -407,6 +409,111 @@ func (p *Process) MemoryMaps(grouped bool) (*[]MemoryMapsStat, error) {
 ** Internal functions
 **/
 
+func limitToInt(val string) (int32, error) {
+	if val == "unlimited" {
+		return math.MaxInt32, nil
+	} else {
+		res, err := strconv.ParseInt(val, 10, 32)
+		if err != nil {
+			return 0, err
+		}
+		return int32(res), nil
+	}
+}
+
+// Get num_fds from /proc/(pid)/limits
+func (p *Process) fillFromLimits() ([]RlimitStat, error) {
+	pid := p.Pid
+	limitsFile := common.HostProc(strconv.Itoa(int(pid)), "limits")
+	d, err := os.Open(limitsFile)
+	if err != nil {
+		return nil, err
+	}
+	defer d.Close()
+
+	var limitStats []RlimitStat
+
+	limitsScanner := bufio.NewScanner(d)
+	for limitsScanner.Scan() {
+		var statItem RlimitStat
+
+		str := strings.Fields(limitsScanner.Text())
+
+		// Remove the header line
+		if strings.Contains(str[len(str)-1], "Units") {
+			continue
+		}
+
+		// Assert that last item is a Hard limit
+		statItem.Hard, err = limitToInt(str[len(str)-1])
+		if err != nil {
+			// On error remove last item an try once again since it can be unit or header line
+			str = str[:len(str)-1]
+			statItem.Hard, err = limitToInt(str[len(str)-1])
+			if err != nil {
+				return nil, err
+			}
+		}
+		// Remove last item from string
+		str = str[:len(str)-1]
+
+		//Now last item is a Soft limit
+		statItem.Soft, err = limitToInt(str[len(str)-1])
+		if err != nil {
+			return nil, err
+		}
+		// Remove last item from string
+		str = str[:len(str)-1]
+
+		//The rest is a stats name
+		resourceName := strings.Join(str, " ")
+		switch resourceName {
+		case "Max cpu time":
+			statItem.Resource = RLIMIT_CPU
+		case "Max file size":
+			statItem.Resource = RLIMIT_FSIZE
+		case "Max data size":
+			statItem.Resource = RLIMIT_DATA
+		case "Max stack size":
+			statItem.Resource = RLIMIT_STACK
+		case "Max core file size":
+			statItem.Resource = RLIMIT_CORE
+		case "Max resident set":
+			statItem.Resource = RLIMIT_RSS
+		case "Max processes":
+			statItem.Resource = RLIMIT_NPROC
+		case "Max open files":
+			statItem.Resource = RLIMIT_NOFILE
+		case "Max locked memory":
+			statItem.Resource = RLIMIT_MEMLOCK
+		case "Max address space":
+			statItem.Resource = RLIMIT_AS
+		case "Max file locks":
+			statItem.Resource = RLIMIT_LOCKS
+		case "Max pending signals":
+			statItem.Resource = RLIMIT_SIGPENDING
+		case "Max msgqueue size":
+			statItem.Resource = RLIMIT_MSGQUEUE
+		case "Max nice priority":
+			statItem.Resource = RLIMIT_NICE
+		case "Max realtime priority":
+			statItem.Resource = RLIMIT_RTPRIO
+		case "Max realtime timeout":
+			statItem.Resource = RLIMIT_RTTIME
+		default:
+			continue
+		}
+
+		limitStats = append(limitStats, statItem)
+	}
+
+	if err := limitsScanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return limitStats, nil
+}
+
 // Get num_fds from /proc/(pid)/fd
 func (p *Process) fillFromfd() (int32, []*OpenFilesStat, error) {
 	pid := p.Pid