Add Process.Refresh

process.go

@@ -12,28 +12,38 @@ import "time"
 type Process interface {
 	// PID returns the process ID for this process.
 	PID() int
+
 	// PPID returns the parent process ID for this process.
 	PPID() int
+
 	// UID returns the numeric user ID for this process. On Windows, it
 	// always returns -1.
 	UID() int
+
 	// GID returns the numeric group ID for this process. On Windows, it
 	// always returns -1.
 	GID() int
+
 	// ExecutablePath returns the full path to the executable of this
 	// process. This information might not be available on all platforms or
 	// if the executable was removed while the process was still running.
 	ExecutablePath() string
+
 	// ExecutableArgs returns the command line arguments for this process,
 	// including the executable name. This information might not be
 	// available on all platforms.
 	ExecutableArgs() []string
+
 	// Command returns the command or executable name running this process.
 	// On some platforms (e.g. macOS and the BSDs) this name might be
 	// truncated.
 	Command() string
+
 	// CreationTime returns the creation time for this process.
 	CreationTime() time.Time
+
+	// Refresh reloads all data associated with this process from the OS.
+	Refresh() error
 }
 
 // Processes returns all currently running processes.

process_test.go

@@ -195,6 +195,17 @@ func TestFindProcessInit(t *testing.T) {
 	}
 }
 
+func TestProcessRefresh(t *testing.T) {
+	proc, err := ps.FindProcess(os.Getpid())
+	if err != nil {
+		t.Fatalf("FindProcess: %v", err)
+	}
+
+	checkOwnProcess(t, proc)
+	proc.Refresh()
+	checkOwnProcess(t, proc)
+}
+
 func BenchmarkProcesses(b *testing.B) {
 	b.ReportAllocs()
 	for b.Loop() {

process_unix.go

@@ -7,6 +7,7 @@
 package ps
 
 import (
+	"fmt"
 	"path/filepath"
 	"time"
 )
@@ -59,3 +60,19 @@ func (p *unixProcess) ExecutableArgs() []string {
 func (p *unixProcess) CreationTime() time.Time {
 	return p.creationTime
 }
+
+func (p *unixProcess) Refresh() error {
+	proc, err := findProcess(p.pid)
+	if err != nil {
+		return fmt.Errorf("failed to refresh process: %w", err)
+	}
+	np := proc.(*unixProcess)
+	p.ppid = np.ppid
+	p.uid = np.uid
+	p.gid = np.gid
+	p.command = np.command
+	p.executablePath = np.executablePath
+	p.executableArgs = np.executableArgs
+	p.creationTime = np.creationTime
+	return nil
+}

process_windows.go

@@ -56,6 +56,20 @@ func (p *windowsProcess) CreationTime() time.Time {
 	return p.creationTime
 }
 
+func (p *windowsProcess) Refresh() error {
+	proc, err := findProcess(p.pid)
+	if err != nil {
+		return err
+	}
+	np := proc.(*windowsProcess)
+	p.ppid = np.ppid
+	p.command = np.command
+	p.executablePath = np.executablePath
+	p.executableArgs = np.executableArgs
+	p.creationTime = np.creationTime
+	return nil
+}
+
 func getCreationTime(pid uint32) time.Time {
 	c, err := windows.OpenProcess(windows.PROCESS_QUERY_LIMITED_INFORMATION, false, pid)
 	if err != nil {