#777 / linux / open_files(): return file position

3 files changed, 41 insertions, 19 deletions

diff --git a/IDEAS b/IDEAS
index 26a9ce25..b8b3a17b 100644
--- a/IDEAS
+++ b/IDEAS
@@ -141,3 +141,9 @@ FEATURES
 - #550: number of threads per core.
 
 - Have psutil.Process().cpu_affinity([]) be an alias for "all CPUs"?
+
+SIMILAR PROJECTS
+================
+
+- https://github.com/hyperic/sigar (Java)
+- zabbix source code: https://zabbix.org/wiki/Get_Zabbix
diff --git a/psutil/_pslinux.py b/psutil/_pslinux.py
index 882cfac8..39f5328d 100644
--- a/psutil/_pslinux.py
+++ b/psutil/_pslinux.py
@@ -237,6 +237,7 @@ sdiskio = namedtuple('sdiskio', ['read_count', 'write_count',
                                  'read_merged_count', 'write_merged_count',
                                  'busy_time'])
 
+popenfile = namedtuple('popenfile', ['path', 'fd', 'position'])
 pmem = namedtuple('pmem', 'rss vms shared text lib data dirty')
 pfullmem = namedtuple('pfullmem', pmem._fields + ('uss', 'pss', 'swap'))
 
@@ -1296,7 +1297,7 @@ class Process(object):
         for fd in files:
             file = "%s/%s/fd/%s" % (self._procfs_path, self.pid, fd)
             try:
-                file = readlink(file)
+                path = readlink(file)
             except OSError as err:
                 # ENOENT == file which is gone in the meantime
                 if err.errno in (errno.ENOENT, errno.ESRCH):
@@ -1308,12 +1309,17 @@ class Process(object):
                 else:
                     raise
             else:
-                # If file is not an absolute path there's no way
-                # to tell whether it's a regular file or not,
-                # so we skip it. A regular file is always supposed
-                # to be absolutized though.
-                if file.startswith('/') and isfile_strict(file):
-                    ntuple = _common.popenfile(file, int(fd))
+                # If path is not an absolute there's no way to tell
+                # whether it's a regular file or not, so we skip it.
+                # A regular file is always supposed to be have an
+                # absolute path though.
+                if path.startswith('/') and isfile_strict(path):
+                    # Get file position.
+                    file = "%s/%s/fdinfo/%s" % (
+                        self._procfs_path, self.pid, fd)
+                    with open_binary(file) as f:
+                        pos = int(f.readline().split()[1])
+                    ntuple = popenfile(path, int(fd), pos)
                     retlist.append(ntuple)
         if hit_enoent:
             # raise NSP if the process disappeared on us
diff --git a/psutil/tests/test_process.py b/psutil/tests/test_process.py
index f1cc1762..1c7993de 100644
--- a/psutil/tests/test_process.py
+++ b/psutil/tests/test_process.py
@@ -876,13 +876,20 @@ class TestProcess(unittest.TestCase):
         p = psutil.Process()
         files = p.open_files()
         self.assertFalse(TESTFN in files)
-        with open(TESTFN, 'w'):
+        with open(TESTFN, 'wb') as f:
+            f.write(b'x' * 1024)
+            f.flush()
             # give the kernel some time to see the new file
-            call_until(p.open_files, "len(ret) != %i" % len(files))
-            filenames = [x.path for x in p.open_files()]
-            self.assertIn(TESTFN, filenames)
-        for file in filenames:
-            assert os.path.isfile(file), file
+            files = call_until(p.open_files, "len(ret) != %i" % len(files))
+            for file in files:
+                if file.path == TESTFN:
+                    if LINUX:
+                        self.assertEqual(file.position, 1024)
+                    break
+            else:
+                self.fail("no file found; files=%s" % repr(files))
+        for file in files:
+            assert os.path.isfile(file.path), file
 
         # another process
         cmdline = "import time; f = open(r'%s', 'r'); time.sleep(60);" % TESTFN
@@ -903,20 +910,20 @@ class TestProcess(unittest.TestCase):
     @unittest.skipIf(BSD, "broken on BSD, see #595")
     @unittest.skipIf(APPVEYOR,
                      "can't find any process file on Appveyor")
-    def test_open_files2(self):
+    def test_open_files_2(self):
         # test fd and path fields
         with open(TESTFN, 'w') as fileobj:
             p = psutil.Process()
-            for path, fd in p.open_files():
-                if path == fileobj.name or fd == fileobj.fileno():
+            for file in p.open_files():
+                if file.path == fileobj.name or file.fd == fileobj.fileno():
                     break
             else:
                 self.fail("no file found; files=%s" % repr(p.open_files()))
-            self.assertEqual(path, fileobj.name)
+            self.assertEqual(file.path, fileobj.name)
             if WINDOWS:
-                self.assertEqual(fd, -1)
+                self.assertEqual(file.fd, -1)
             else:
-                self.assertEqual(fd, fileobj.fileno())
+                self.assertEqual(file.fd, fileobj.fileno())
             # test positions
             ntuple = p.open_files()[0]
             self.assertEqual(ntuple[0], ntuple.path)
@@ -1694,6 +1701,9 @@ class TestFetchAllProcesses(unittest.TestCase):
                 assert f.fd == -1, f
             else:
                 self.assertIsInstance(f.fd, int)
+            if LINUX:
+                self.assertIsInstance(f.position, int)
+                self.assertGreaterEqual(f.position, 0)
             if BSD and not f.path:
                 # XXX see: https://github.com/giampaolo/psutil/issues/595
                 continue