1 files changed, 71 insertions, 0 deletions
diff --git a/python/psutil/examples/pstree.py b/python/psutil/examples/pstree.py
new file mode 100644
index 000000000..1bf8c9c04
--- /dev/null
+++ b/python/psutil/examples/pstree.py
@@ -0,0 +1,71 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Similar to 'ps aux --forest' on Linux, prints the process list
+as a tree structure.
+
+$ python examples/pstree.py
+0 ?
+|- 1 init
+| |- 289 cgmanager
+| |- 616 upstart-socket-bridge
+| |- 628 rpcbind
+| |- 892 upstart-file-bridge
+| |- 907 dbus-daemon
+| |- 978 avahi-daemon
+| | `_ 979 avahi-daemon
+| |- 987 NetworkManager
+| | |- 2242 dnsmasq
+| | `_ 10699 dhclient
+| |- 993 polkitd
+| |- 1061 getty
+| |- 1066 su
+| | `_ 1190 salt-minion...
+...
+"""
+
+from __future__ import print_function
+import collections
+import sys
+
+import psutil
+
+
+def print_tree(parent, tree, indent=''):
+    try:
+        name = psutil.Process(parent).name()
+    except psutil.Error:
+        name = "?"
+    print(parent, name)
+    if parent not in tree:
+        return
+    children = tree[parent][:-1]
+    for child in children:
+        sys.stdout.write(indent + "|- ")
+        print_tree(child, tree, indent + "| ")
+    child = tree[parent][-1]
+    sys.stdout.write(indent + "`_ ")
+    print_tree(child, tree, indent + "  ")
+
+
+def main():
+    # construct a dict where 'values' are all the processes
+    # having 'key' as their parent
+    tree = collections.defaultdict(list)
+    for p in psutil.process_iter():
+        try:
+            tree[p.ppid()].append(p.pid)
+        except (psutil.NoSuchProcess, psutil.ZombieProcess):
+            pass
+    # on systems supporting PID 0, PID 0's parent is usually 0
+    if 0 in tree and 0 in tree[0]:
+        tree[0].remove(0)
+    print_tree(min(tree), tree)
+
+
+if __name__ == '__main__':
+    main()