.. module:: psutil
   :synopsis: psutil module
.. moduleauthor:: Giampaolo Rodola' <grodola@gmail.com>

psutil documentation
====================

Quick links
-----------

* `Home page <https://github.com/giampaolo/psutil>`__
* `Install <https://github.com/giampaolo/psutil/blob/master/INSTALL.rst>`_
* `Blog <http://grodola.blogspot.com/search/label/psutil>`__
* `Forum <http://groups.google.com/group/psutil/topics>`__
* `Download <https://pypi.python.org/pypi?:action=display&name=psutil#downloads>`__
* `Development guide <https://github.com/giampaolo/psutil/blob/master/DEVGUIDE.rst>`_
* `What's new <https://github.com/giampaolo/psutil/blob/master/HISTORY.rst>`__

About
-----

psutil (python system and process utilities) is a cross-platform library for
retrieving information on running
**processes** and **system utilization** (CPU, memory, disks, network) in
**Python**.
It is useful mainly for **system monitoring**, **profiling** and **limiting
process resources** and **management of running processes**.
It implements many functionalities offered by command line tools
such as: *ps, top, lsof, netstat, ifconfig, who, df, kill, free, nice,
ionice, iostat, iotop, uptime, pidof, tty, taskset, pmap*.
It currently supports **Linux, Windows, OSX, Sun Solaris, FreeBSD, OpenBSD**
and **NetBSD**, both **32-bit** and **64-bit** architectures, with Python
versions from **2.6 to 3.5** (users of Python 2.4 and 2.5 may use
`2.1.3 <https://pypi.python.org/pypi?name=psutil&version=2.1.3&:action=files>`__ version).
`PyPy <http://pypy.org/>`__ is also known to work.

The psutil documentation you're reading is distributed as a single HTML page.

System related functions
========================

CPU
---

.. function:: cpu_times(percpu=False)

  Return system CPU times as a namedtuple.
  Every attribute represents the seconds the CPU has spent in the given mode.
  The attributes availability varies depending on the platform:

  - **user**
  - **system**
  - **idle**

  Platform-specific fields:

  - **nice** *(UNIX)*
  - **iowait** *(Linux)*
  - **irq** *(Linux, BSD)*
  - **softirq** *(Linux)*
  - **steal** *(Linux 2.6.11+)*
  - **guest** *(Linux 2.6.24+)*
  - **guest_nice** *(Linux 3.2.0+)*
  - **interrupt** *(Windows)*
  - **dpc** *(Windows)*

  When *percpu* is ``True`` return a list of namedtuples for each logical CPU
  on the system.
  First element of the list refers to first CPU, second element to second CPU
  and so on.
  The order of the list is consistent across calls.
  Example output on Linux:

    >>> import psutil
    >>> psutil.cpu_times()
    scputimes(user=17411.7, nice=77.99, system=3797.02, idle=51266.57, iowait=732.58, irq=0.01, softirq=142.43, steal=0.0, guest=0.0, guest_nice=0.0)

  .. versionchanged:: 4.1.0 added *interrupt* and *dpc* fields on Windows.

.. function:: cpu_percent(interval=None, percpu=False)

  Return a float representing the current system-wide CPU utilization as a
  percentage. When *interval* is > ``0.0`` compares system CPU times elapsed
  before and after the interval (blocking).
  When *interval* is ``0.0`` or ``None`` compares system CPU times elapsed
  since last call or module import, returning immediately.
  That means the first time this is called it will return a meaningless ``0.0``
  value which you are supposed to ignore.
  In this case is recommended for accuracy that this function be called with at
  least ``0.1`` seconds between calls.
  When *percpu* is ``True`` returns a list of floats representing the
  utilization as a percentage for each CPU.
  First element of the list refers to first CPU, second element to second CPU
  and so on. The order of the list is consistent across calls.

    >>> import psutil
    >>> # blocking
    >>> psutil.cpu_percent(interval=1)
    2.0
    >>> # non-blocking (percentage since last call)
    >>> psutil.cpu_percent(interval=None)
    2.9
    >>> # blocking, per-cpu
    >>> psutil.cpu_percent(interval=1, percpu=True)
    [2.0, 1.0]
    >>>

  .. warning::
    the first time this function is called with *interval* = ``0.0`` or ``None``
    it will return a meaningless ``0.0`` value which you are supposed to
    ignore.

.. function:: cpu_times_percent(interval=None, percpu=False)

  Same as :func:`cpu_percent()` but provides utilization percentages for each
  specific CPU time as is returned by
  :func:`psutil.cpu_times(percpu=True)<cpu_times()>`.
  *interval* and
  *percpu* arguments have the same meaning as in :func:`cpu_percent()`.

  .. warning::
    the first time this function is called with *interval* = ``0.0`` or
    ``None`` it will return a meaningless ``0.0`` value which you are supposed
    to ignore.

  .. versionchanged::
    4.1.0 two new *interrupt* and *dpc* fields are returned on Windows.

.. function:: cpu_count(logical=True)

  Return the number of logical CPUs in the system (same as
  `os.cpu_count() <http://docs.python.org/3/library/os.html#os.cpu_count>`__
  in Python 3.4).
  If *logical* is ``False`` return the number of physical cores only (hyper
  thread CPUs are excluded). Return ``None`` if undetermined.

    >>> import psutil
    >>> psutil.cpu_count()
    4
    >>> psutil.cpu_count(logical=False)
    2
    >>>

.. function:: cpu_stats()

  Return various CPU statistics as a namedtuple:

  - **ctx_switches**:
    number of context switches (voluntary + involuntary) since boot.
  - **interrupts**:
    number of interrupts since boot.
  - **soft_interrupts**:
    number of software interrupts since boot. Always set to ``0`` on Windows
    and SunOS.
  - **syscalls**: number of system calls since boot. Always set to ``0`` on
    Linux.

  Example (Linux):

  .. code-block:: python

     >>> import psutil
     >>> psutil.cpu_stats()
     scpustats(ctx_switches=20455687, interrupts=6598984, soft_interrupts=2134212, syscalls=0)

  .. versionadded:: 4.1.0


Memory
------

.. function:: virtual_memory()

  Return statistics about system memory usage as a namedtuple including the
  following fields, expressed in bytes:

  - **total**: total physical memory available.
  - **available**: the actual amount of available memory that can be given
    instantly to processes that request more memory in bytes; this is
    calculated by summing different memory values depending on the platform
    (e.g. free + buffers + cached on Linux) and it is supposed to be used to
    monitor actual memory usage in a cross platform fashion.
  - **percent**: the percentage usage calculated as
    ``(total - available) / total * 100``.
  - **used**: memory used, calculated differently depending on the platform and
    designed for informational purposes only.
  - **free**: memory not being used at all (zeroed) that is readily available;
    note that this doesn't reflect the actual memory available (use 'available'
    instead).

  Platform-specific fields:

  - **active** *(UNIX)*: memory currently in use or very recently used, and so
    it is in RAM.
  - **inactive** *(UNIX)*: memory that is marked as not used.
  - **buffers** *(Linux, BSD)*: cache for things like file system metadata.
  - **cached** *(Linux, BSD)*: cache for various things.
  - **shared** *(Linux, BSD)*: memory that may be simultaneously accessed by
    multiple processes.
  - **wired** *(BSD, OSX)*: memory that is marked to always stay in RAM. It is
    never moved to disk.

  The sum of **used** and **available** does not necessarily equal **total**.
  On Windows **available** and **free** are the same.
  See `scripts/meminfo.py <https://github.com/giampaolo/psutil/blob/master/scripts/meminfo.py>`__
  script providing an example on how to convert bytes in a human readable form.

  .. note:: if you just want to know how much physical memory is left in a
    cross platform fashion simply rely on the **available** field.

  >>> import psutil
  >>> mem = psutil.virtual_memory()
  >>> mem
  svmem(total=10367352832, available=6472179712, percent=37.6, used=8186245120, free=2181107712, active=4748992512, inactive=2758115328, buffers=790724608, cached=3500347392, shared=787554304)
  >>>
  >>> THRESHOLD = 100 * 1024 * 1024  # 100MB
  >>> if mem.available <= THRESHOLD:
  ...     print("warning")
  ...
  >>>

  .. versionchanged:: 4.2.0 added *shared* metrics on Linux.

.. function:: swap_memory()

  Return system swap memory statistics as a namedtuple including the following
  fields:

  * **total**: total swap memory in bytes
  * **used**: used swap memory in bytes
  * **free**: free swap memory in bytes
  * **percent**: the percentage usage calculated as ``(total - available) / total * 100``
  * **sin**: the number of bytes the system has swapped in from disk
    (cumulative)
  * **sout**: the number of bytes the system has swapped out from disk
    (cumulative)

  **sin** and **sout** on Windows are always set to ``0``.
  See `scripts/meminfo.py <https://github.com/giampaolo/psutil/blob/master/scripts/meminfo.py>`__
  script providing an example on how to convert bytes in a human readable form.

    >>> import psutil
    >>> psutil.swap_memory()
    sswap(total=2097147904L, used=886620160L, free=1210527744L, percent=42.3, sin=1050411008, sout=1906720768)

Disks
-----

.. function:: disk_partitions(all=False)

  Return all mounted disk partitions as a list of namedtuples including device,
  mount point and filesystem type, similarly to "df" command on UNIX. If *all*
  parameter is ``False`` return physical devices only (e.g. hard disks, cd-rom
  drives, USB keys) and ignore all others (e.g. memory partitions such as
  `/dev/shm <http://www.cyberciti.biz/tips/what-is-devshm-and-its-practical-usage.html>`__).
  Namedtuple's **fstype** field is a string which varies depending on the
  platform.
  On Linux it can be one of the values found in /proc/filesystems (e.g.
  ``'ext3'`` for an ext3 hard drive o ``'iso9660'`` for the CD-ROM drive).
  On Windows it is determined via
  `GetDriveType <http://msdn.microsoft.com/en-us/library/aa364939(v=vs.85).aspx>`__
  and can be either ``"removable"``, ``"fixed"``, ``"remote"``, ``"cdrom"``,
  ``"unmounted"`` or ``"ramdisk"``. On OSX and BSD it is retrieved via
  `getfsstat(2) <http://www.manpagez.com/man/2/getfsstat/>`__. See
  `disk_usage.py <https://github.com/giampaolo/psutil/blob/master/scripts/disk_usage.py>`__
  script providing an example usage.

    >>> import psutil
    >>> psutil.disk_partitions()
    [sdiskpart(device='/dev/sda3', mountpoint='/', fstype='ext4', opts='rw,errors=remount-ro'),
     sdiskpart(device='/dev/sda7', mountpoint='/home', fstype='ext4', opts='rw')]

.. function:: disk_usage(path)

  Return disk usage statistics about the given *path* as a namedtuple including
  **total**, **used** and **free** space expressed in bytes, plus the
  **percentage** usage.
  `OSError <http://docs.python.org/3/library/exceptions.html#OSError>`__ is
  raised if *path* does not exist.
  Starting from `Python 3.3 <http://bugs.python.org/issue12442>`__  this is
  also available as
  `shutil.disk_usage() <http://docs.python.org/3/library/shutil.html#shutil.disk_usage>`__.
  See `disk_usage.py <https://github.com/giampaolo/psutil/blob/master/scripts/disk_usage.py>`__ script providing an example usage.

    >>> import psutil
    >>> psutil.disk_usage('/')
    sdiskusage(total=21378641920, used=4809781248, free=15482871808, percent=22.5)

  .. note::
    UNIX usually reserves 5% of the total disk space for the root user.
    *total* and *used* fields on UNIX refer to the overall total and used
    space, whereas *free* represents the space available for the **user** and
    *percent* represents the **user** utilization (see
    `source code <https://github.com/giampaolo/psutil/blob/3dea30d583b8c1275057edb1b3b720813b4d0f60/psutil/_psposix.py#L123>`__).
    That is why *percent* value may look 5% bigger than what you would expect
    it to be.
    Also note that both 4 values match "df" cmdline utility.

  .. versionchanged::
    4.3.0 *percent* value takes root reserved space into account.

.. function:: disk_io_counters(perdisk=False)

  Return system-wide disk I/O statistics as a namedtuple including the
  following fields:

  - **read_count**: number of reads
  - **write_count**: number of writes
  - **read_bytes**: number of bytes read
  - **write_bytes**: number of bytes written

  Platform-specific fields:

  - **read_time**: (all except *NetBSD* and *OpenBSD*) time spent reading from
    disk (in milliseconds)
  - **write_time**: (all except *NetBSD* and *OpenBSD*) time spent writing to disk
    (in milliseconds)
  - **busy_time**: (*Linux*, *FreeBSD*) time spent doing actual I/Os (in
    milliseconds)
  - **read_merged_count** (*Linux*): number of merged reads
    (see `iostat doc <https://www.kernel.org/doc/Documentation/iostats.txt>`__)
  - **write_merged_count** (*Linux*): number of merged writes
    (see `iostats doc <https://www.kernel.org/doc/Documentation/iostats.txt>`__)

  If *perdisk* is ``True`` return the same information for every physical disk
  installed on the system as a dictionary with partition names as the keys and
  the namedtuple described above as the values.
  See `scripts/iotop.py <https://github.com/giampaolo/psutil/blob/master/scripts/iotop.py>`__
  for an example application.

    >>> import psutil
    >>> psutil.disk_io_counters()
    sdiskio(read_count=8141, write_count=2431, read_bytes=290203, write_bytes=537676, read_time=5868, write_time=94922)
    >>>
    >>> psutil.disk_io_counters(perdisk=True)
    {'sda1': sdiskio(read_count=920, write_count=1, read_bytes=2933248, write_bytes=512, read_time=6016, write_time=4),
     'sda2': sdiskio(read_count=18707, write_count=8830, read_bytes=6060, write_bytes=3443, read_time=24585, write_time=1572),
     'sdb1': sdiskio(read_count=161, write_count=0, read_bytes=786432, write_bytes=0, read_time=44, write_time=0)}

  .. warning::
    on some systems such as Linux, on a very busy or long-lived system these
    numbers may wrap (restart from zero), see
    `issues #802 <https://github.com/giampaolo/psutil/issues/802>`__.
    Applications should be prepared to deal with that.

  .. versionchanged::
    4.0.0 added *busy_time* (Linux, FreeBSD), *read_merged_count* and
    *write_merged_count* (Linux) fields.

  .. versionchanged::
    4.0.0 NetBSD no longer has *read_time* and *write_time* fields.

Network
-------

.. function:: net_io_counters(pernic=False)

  Return system-wide network I/O statistics as a namedtuple including the
  following attributes:

  - **bytes_sent**: number of bytes sent
  - **bytes_recv**: number of bytes received
  - **packets_sent**: number of packets sent
  - **packets_recv**: number of packets received
  - **errin**: total number of errors while receiving
  - **errout**: total number of errors while sending
  - **dropin**: total number of incoming packets which were dropped
  - **dropout**: total number of outgoing packets which were dropped (always 0
    on OSX and BSD)

  If *pernic* is ``True`` return the same information for every network
  interface installed on the system as a dictionary with network interface
  names as the keys and the namedtuple described above as the values.
  See `scripts/nettop.py <https://github.com/giampaolo/psutil/blob/master/scripts/nettop.py>`__
  for an example application.

    >>> import psutil
    >>> psutil.net_io_counters()
    snetio(bytes_sent=14508483, bytes_recv=62749361, packets_sent=84311, packets_recv=94888, errin=0, errout=0, dropin=0, dropout=0)
    >>>
    >>> psutil.net_io_counters(pernic=True)
    {'lo': snetio(bytes_sent=547971, bytes_recv=547971, packets_sent=5075, packets_recv=5075, errin=0, errout=0, dropin=0, dropout=0),
    'wlan0': snetio(bytes_sent=13921765, bytes_recv=62162574, packets_sent=79097, packets_recv=89648, errin=0, errout=0, dropin=0, dropout=0)}

  .. warning::
    on some systems such as Linux, on a very busy or long-lived system these
    numbers may wrap (restart from zero), see
    `issues #802 <https://github.com/giampaolo/psutil/issues/802>`__.
    Applications should be prepared to deal with that.

.. function:: net_connections(kind='inet')

  Return system-wide socket connections as a list of namedtuples.
  Every namedtuple provides 7 attributes:

  - **fd**: the socket file descriptor, if retrievable, else ``-1``.
    If the connection refers to the current process this may be passed to
    `socket.fromfd() <http://docs.python.org/library/socket.html#socket.fromfd>`__
    to obtain a usable socket object.
  - **family**: the address family, either `AF_INET
    <http://docs.python.org//library/socket.html#socket.AF_INET>`__,
    `AF_INET6 <http://docs.python.org//library/socket.html#socket.AF_INET6>`__
    or `AF_UNIX <http://docs.python.org//library/socket.html#socket.AF_UNIX>`__.
  - **type**: the address type, either `SOCK_STREAM
    <http://docs.python.org//library/socket.html#socket.SOCK_STREAM>`__ or
    `SOCK_DGRAM
    <http://docs.python.org//library/socket.html#socket.SOCK_DGRAM>`__.
  - **laddr**: the local address as a ``(ip, port)`` tuple or a ``path``
    in case of AF_UNIX sockets.
  - **raddr**: the remote address as a ``(ip, port)`` tuple or an absolute
    ``path`` in case of UNIX sockets.
    When the remote endpoint is not connected you'll get an empty tuple
    (AF_INET*) or ``None`` (AF_UNIX).
    On Linux AF_UNIX sockets will always have this set to ``None``.
  - **status**: represents the status of a TCP connection. The return value
    is one of the :data:`psutil.CONN_* <psutil.CONN_ESTABLISHED>` constants
    (a string).
    For UDP and UNIX sockets this is always going to be
    :const:`psutil.CONN_NONE`.
  - **pid**: the PID of the process which opened the socket, if retrievable,
    else ``None``. On some platforms (e.g. Linux) the availability of this
    field changes depending on process privileges (root is needed).

  The *kind* parameter is a string which filters for connections that fit the
  following criteria:

  .. table::

   +----------------+-----------------------------------------------------+
   | **Kind value** | **Connections using**                               |
   +================+=====================================================+
   | "inet"         | IPv4 and IPv6                                       |
   +----------------+-----------------------------------------------------+
   | "inet4"        | IPv4                                                |
   +----------------+-----------------------------------------------------+
   | "inet6"        | IPv6                                                |
   +----------------+-----------------------------------------------------+
   | "tcp"          | TCP                                                 |
   +----------------+-----------------------------------------------------+
   | "tcp4"         | TCP over IPv4                                       |
   +----------------+-----------------------------------------------------+
   | "tcp6"         | TCP over IPv6                                       |
   +----------------+-----------------------------------------------------+
   | "udp"          | UDP                                                 |
   +----------------+-----------------------------------------------------+
   | "udp4"         | UDP over IPv4                                       |
   +----------------+-----------------------------------------------------+
   | "udp6"         | UDP over IPv6                                       |
   +----------------+-----------------------------------------------------+
   | "unix"         | UNIX socket (both UDP and TCP protocols)            |
   +----------------+-----------------------------------------------------+
   | "all"          | the sum of all the possible families and protocols  |
   +----------------+-----------------------------------------------------+

  On OSX this function requires root privileges.
  To get per-process connections use :meth:`Process.connections`.
  Also, see
  `netstat.py sample script <https://github.com/giampaolo/psutil/blob/master/scripts/netstat.py>`__.
  Example:

    >>> import psutil
    >>> psutil.net_connections()
    [pconn(fd=115, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 48776), raddr=('93.186.135.91', 80), status='ESTABLISHED', pid=1254),
     pconn(fd=117, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 43761), raddr=('72.14.234.100', 80), status='CLOSING', pid=2987),
     pconn(fd=-1, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 60759), raddr=('72.14.234.104', 80), status='ESTABLISHED', pid=None),
     pconn(fd=-1, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 51314), raddr=('72.14.234.83', 443), status='SYN_SENT', pid=None)
     ...]

  .. note::
    (OSX) :class:`psutil.AccessDenied` is always raised unless running as root
    (lsof does the same).

  .. note::
    (Solaris) UNIX sockets are not supported.

  .. versionadded:: 2.1.0

.. function:: net_if_addrs()

  Return the addresses associated to each NIC (network interface card)
  installed on the system as a dictionary whose keys are the NIC names and
  value is a list of namedtuples for each address assigned to the NIC.
  Each namedtuple includes 5 fields:

  - **family**
  - **address**
  - **netmask**
  - **broadcast**
  - **ptp**

  *family* can be either
  `AF_INET <http://docs.python.org//library/socket.html#socket.AF_INET>`__,
  `AF_INET6 <http://docs.python.org//library/socket.html#socket.AF_INET6>`__
  or :const:`psutil.AF_LINK`, which refers to a MAC address.
  *address* is the primary address and it is always set.
  *netmask*, *broadcast* and *ptp* may be ``None``.
  *ptp* stands for "point to point" and references the destination address on a
  point to point interface (tipically a VPN).
  *broadcast* and *ptp* are mutually exclusive.
  *netmask*, *broadcast* and *ptp* are not supported on Windows and are set to
  ``None``.

  Example::

    >>> import psutil
    >>> psutil.net_if_addrs()
    {'lo': [snic(family=<AddressFamily.AF_INET: 2>, address='127.0.0.1', netmask='255.0.0.0', broadcast='127.0.0.1', ptp=None),
            snic(family=<AddressFamily.AF_INET6: 10>, address='::1', netmask='ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff', broadcast=None, ptp=None),
            snic(family=<AddressFamily.AF_LINK: 17>, address='00:00:00:00:00:00', netmask=None, broadcast='00:00:00:00:00:00', ptp=None)],
     'wlan0': [snic(family=<AddressFamily.AF_INET: 2>, address='192.168.1.3', netmask='255.255.255.0', broadcast='192.168.1.255', ptp=None),
               snic(family=<AddressFamily.AF_INET6: 10>, address='fe80::c685:8ff:fe45:641%wlan0', netmask='ffff:ffff:ffff:ffff::', broadcast=None, ptp=None),
               snic(family=<AddressFamily.AF_LINK: 17>, address='c4:85:08:45:06:41', netmask=None, broadcast='ff:ff:ff:ff:ff:ff', ptp=None)]}
    >>>

  See also `scripts/ifconfig.py <https://github.com/giampaolo/psutil/blob/master/scripts/ifconfig.py>`__
  for an example application.

  .. note::
    if you're interested in others families (e.g. AF_BLUETOOTH) you can use
    the more powerful `netifaces <https://pypi.python.org/pypi/netifaces/>`__
    extension.

  .. note::
    you can have more than one address of the same family associated with each
    interface (that's why dict values are lists).

  .. note::
    *netmask*, *broadcast* and *ptp* are not supported on Windows and are set
    to ``None``.

  .. versionadded:: 3.0.0

  .. versionchanged:: 3.2.0 *ptp* field was added.

.. function:: net_if_stats()

  Return information about each NIC (network interface card) installed on the
  system as a dictionary whose keys are the NIC names and value is a namedtuple
  with the following fields:

  - **isup**: a bool indicating whether the NIC is up and running.
  - **duplex**: the duplex communication type;
    it can be either :const:`NIC_DUPLEX_FULL`, :const:`NIC_DUPLEX_HALF` or
    :const:`NIC_DUPLEX_UNKNOWN`.
  - **speed**: the NIC speed expressed in mega bits (MB), if it can't be
    determined (e.g. 'localhost') it will be set to ``0``.
  - **mtu**: NIC's maximum transmission unit expressed in bytes.

  See also `scripts/ifconfig.py <https://github.com/giampaolo/psutil/blob/master/scripts/ifconfig.py>`__
  for an example application.
  Example:

    >>> import psutil
    >>> psutil.net_if_stats()
    {'eth0': snicstats(isup=True, duplex=<NicDuplex.NIC_DUPLEX_FULL: 2>, speed=100, mtu=1500),
     'lo': snicstats(isup=True, duplex=<NicDuplex.NIC_DUPLEX_UNKNOWN: 0>, speed=0, mtu=65536)}

  .. versionadded:: 3.0.0


Other system info
-----------------

.. function:: boot_time()

  Return the system boot time expressed in seconds since the epoch.
  Example:

  .. code-block:: python

     >>> import psutil, datetime
     >>> psutil.boot_time()
     1389563460.0
     >>> datetime.datetime.fromtimestamp(psutil.boot_time()).strftime("%Y-%m-%d %H:%M:%S")
     '2014-01-12 22:51:00'

.. function:: users()

  Return users currently connected on the system as a list of namedtuples
  including the following fields:

  - **user**: the name of the user.
  - **terminal**: the tty or pseudo-tty associated with the user, if any,
    else ``None``.
  - **host**: the host name associated with the entry, if any.
  - **started**: the creation time as a floating point number expressed in
    seconds since the epoch.

  Example::

    >>> import psutil
    >>> psutil.users()
    [suser(name='giampaolo', terminal='pts/2', host='localhost', started=1340737536.0),
     suser(name='giampaolo', terminal='pts/3', host='localhost', started=1340737792.0)]

Processes
=========

Functions
---------

.. function:: pids()

  Return a list of current running PIDs. To iterate over all processes
  :func:`process_iter()` should be preferred.

.. function:: pid_exists(pid)

  Check whether the given PID exists in the current process list. This is
  faster than doing ``"pid in psutil.pids()"`` and should be preferred.

.. function:: process_iter()

  Return an iterator yielding a :class:`Process` class instance for all running
  processes on the local machine.
  Every instance is only created once and then cached into an internal table
  which is updated every time an element is yielded.
  Cached :class:`Process` instances are checked for identity so that you're
  safe in case a PID has been reused by another process, in which case the
  cached instance is updated.
  This is should be preferred over :func:`psutil.pids()` for iterating over
  processes.
  Sorting order in which processes are returned is
  based on their PID. Example usage::

    import psutil

    for proc in psutil.process_iter():
        try:
            pinfo = proc.as_dict(attrs=['pid', 'name'])
        except psutil.NoSuchProcess:
            pass
        else:
            print(pinfo)

.. function:: wait_procs(procs, timeout=None, callback=None)

  Convenience function which waits for a list of :class:`Process` instances to
  terminate. Return a ``(gone, alive)`` tuple indicating which processes are
  gone and which ones are still alive. The *gone* ones will have a new
  *returncode* attribute indicating process exit status (it may be ``None``).
  ``callback`` is a function which gets called every time a process terminates
  (a :class:`Process` instance is passed as callback argument). Function will
  return as soon as all processes terminate or when timeout occurs. Tipical use
  case is:

  - send SIGTERM to a list of processes
  - give them some time to terminate
  - send SIGKILL to those ones which are still alive

  Example::

    import psutil

    def on_terminate(proc):
        print("process {} terminated with exit code {}".format(proc, proc.returncode))

    procs = [...]  # a list of Process instances
    for p in procs:
        p.terminate()
    gone, alive = wait_procs(procs, timeout=3, callback=on_terminate)
    for p in alive:
        p.kill()

Exceptions
----------

.. class:: Error()

  Base exception class. All other exceptions inherit from this one.

.. class:: NoSuchProcess(pid, name=None, msg=None)

  Raised by :class:`Process` class methods when no process with the given
  pid* is found in the current process list or when a process no longer
  exists. "name" is the name the process had before disappearing
  and gets set only if :meth:`Process.name()` was previosly called.

.. class:: ZombieProcess(pid, name=None, ppid=None, msg=None)

  This may be raised by :class:`Process` class methods when querying a zombie
  process on UNIX (Windows doesn't have zombie processes). Depending on the
  method called the OS may be able to succeed in retrieving the process
  information or not.
  Note: this is a subclass of :class:`NoSuchProcess` so if you're not
  interested in retrieving zombies (e.g. when using :func:`process_iter()`)
  you can ignore this exception and just catch :class:`NoSuchProcess`.

  .. versionadded:: 3.0.0

.. class:: AccessDenied(pid=None, name=None, msg=None)

  Raised by :class:`Process` class methods when permission to perform an
  action is denied. "name" is the name of the process (may be ``None``).

.. class:: TimeoutExpired(seconds, pid=None, name=None, msg=None)

  Raised by :meth:`Process.wait` if timeout expires and process is still
  alive.

Process class
-------------

.. class:: Process(pid=None)

  Represents an OS process with the given *pid*. If *pid* is omitted current
  process *pid* (`os.getpid() <http://docs.python.org/library/os.html#os.getpid>`__)
  is used.
  Raise :class:`NoSuchProcess` if *pid* does not exist.
  When accessing methods of this class always be  prepared to catch
  :class:`NoSuchProcess`, :class:`ZombieProcess` and :class:`AccessDenied`
  exceptions.
  `hash() <http://docs.python.org/2/library/functions.html#hash>`__ builtin can
  be used against instances of this class in order to identify a process
  univocally over time (the hash is determined by mixing process PID
  and creation time). As such it can also be used with
  `set()s <http://docs.python.org/2/library/stdtypes.html#types-set>`__.

  .. warning::

    the way this class is bound to a process is via its **PID**.
    That means that if the :class:`Process` instance is old enough and
    the PID has been reused in the meantime you might end up interacting
    with another process.
    The only exceptions for which process identity is preemptively checked
    (via PID + creation time) and guaranteed are for
    :meth:`nice` (set),
    :meth:`ionice`  (set),
    :meth:`cpu_affinity` (set),
    :meth:`rlimit` (set),
    :meth:`children`,
    :meth:`parent`,
    :meth:`suspend`
    :meth:`resume`,
    :meth:`send_signal`,
    :meth:`terminate`, and
    :meth:`kill`
    methods.
    To prevent this problem for all other methods you can use
    :meth:`is_running()` before querying the process or use
    :func:`process_iter()` in case you're iterating over all processes.

  .. attribute:: pid

    The process PID.

  .. method:: ppid()

    The process parent pid.  On Windows the return value is cached after first
    call.

  .. method:: name()

    The process name.

  .. method:: exe()

    The process executable as an absolute path.
    On some systems this may also be an empty string.
    The return value is cached after first call.

  .. method:: cmdline()

    The command line this process has been called with.

  .. method:: environ()

    The environment variables of the process as a dict.  Note: this might not
    reflect changes made after the process started.

    Availability: Linux, OSX, Windows

    .. versionadded:: 4.0.0

  .. method:: create_time()

    The process creation time as a floating point number expressed in seconds
    since the epoch, in
    `UTC <http://en.wikipedia.org/wiki/Coordinated_universal_time>`__.
    The return value is cached after first call.

      >>> import psutil, datetime
      >>> p = psutil.Process()
      >>> p.create_time()
      1307289803.47
      >>> datetime.datetime.fromtimestamp(p.create_time()).strftime("%Y-%m-%d %H:%M:%S")
      '2011-03-05 18:03:52'

  .. method:: as_dict(attrs=None, ad_value=None)

    Utility method retrieving multiple process information as a dictionary.
    If *attrs* is specified it must be a list of strings reflecting available
    :class:`Process` class's attribute names (e.g. ``['cpu_times', 'name']``),
    else all public (read only) attributes are assumed. *ad_value* is the
    value which gets assigned to a dict key in case :class:`AccessDenied`
    or :class:`ZombieProcess` exception is raised when retrieving that
    particular process information.

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.as_dict(attrs=['pid', 'name', 'username'])
      {'username': 'giampaolo', 'pid': 12366, 'name': 'python'}

    .. versionchanged::
      3.0.0 *ad_value* is used also when incurring into
      :class:`ZombieProcess` exception, not only :class:`AccessDenied`

  .. method:: parent()

    Utility method which returns the parent process as a :class:`Process`
    object preemptively checking whether PID has been reused. If no parent
    PID is known return ``None``.

  .. method:: status()

    The current process status as a string. The returned string is one of the
    :data:`psutil.STATUS_*<psutil.STATUS_RUNNING>` constants.

  .. method:: cwd()

    The process current working directory as an absolute path.

  .. method:: username()

    The name of the user that owns the process. On UNIX this is calculated by
    using real process uid.

  .. method:: uids()

    The real, effective and saved user ids of this process as a
    namedtuple. This is the same as
    `os.getresuid() <http://docs.python.org//library/os.html#os.getresuid>`__
    but can be used for any process PID.

    Availability: UNIX

  .. method:: gids()

    The real, effective and saved group ids of this process as a
    namedtuple. This is the same as
    `os.getresgid() <http://docs.python.org//library/os.html#os.getresgid>`__
    but can be used for any process PID.

    Availability: UNIX

  .. method:: terminal()

    The terminal associated with this process, if any, else ``None``. This is
    similar to "tty" command but can be used for any process PID.

    Availability: UNIX

  .. method:: nice(value=None)

    Get or set process
    `niceness <blogs.techrepublic.com.com/opensource/?p=140>`__ (priority).
    On UNIX this is a number which usually goes from ``-20`` to ``20``.
    The higher the nice value, the lower the priority of the process.

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.nice(10)  # set
      >>> p.nice()  # get
      10
      >>>

    Starting from `Python 3.3 <http://bugs.python.org/issue10784>`__ this
    functionality is also available as
    `os.getpriority() <http://docs.python.org/3/library/os.html#os.getpriority>`__
    and
    `os.setpriority() <http://docs.python.org/3/library/os.html#os.setpriority>`__
    (UNIX only).
    On Windows this is implemented via
    `GetPriorityClass <http://msdn.microsoft.com/en-us/library/ms683211(v=vs.85).aspx>`__
    and `SetPriorityClass <http://msdn.microsoft.com/en-us/library/ms686219(v=vs.85).aspx>`__
    Windows APIs and *value* is one of the
    :data:`psutil.*_PRIORITY_CLASS <psutil.ABOVE_NORMAL_PRIORITY_CLASS>`
    constants reflecting the MSDN documentation.
    Example which increases process priority on Windows:

      >>> p.nice(psutil.HIGH_PRIORITY_CLASS)

  .. method:: ionice(ioclass=None, value=None)

    Get or set
    `process I/O niceness <http://friedcpu.wordpress.com/2007/07/17/why-arent-you-using-ionice-yet/>`__ (priority).
    On Linux *ioclass* is one of the
    :data:`psutil.IOPRIO_CLASS_*<psutil.IOPRIO_CLASS_NONE>` constants.
    *value* is a number which goes from  ``0`` to ``7``. The higher the value,
    the lower the I/O priority of the process. On Windows only *ioclass* is
    used and it can be set to ``2`` (normal), ``1`` (low) or ``0`` (very low).
    The example below sets IDLE priority class for the current process,
    meaning it will only get I/O time when no other process needs the disk:

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.ionice(psutil.IOPRIO_CLASS_IDLE)  # set
      >>> p.ionice()  # get
      pionice(ioclass=<IOPriority.IOPRIO_CLASS_IDLE: 3>, value=0)
      >>>

    On Windows only *ioclass* is used and it can be set to ``2`` (normal),
    ``1`` (low) or ``0`` (very low).

    Availability: Linux and Windows > Vista

    .. versionchanged::
      3.0.0 on Python >= 3.4 the returned ``ioclass`` constant is an
      `enum <https://docs.python.org/3/library/enum.html#module-enum>`__
      instead of a plain integer.

  .. method:: rlimit(resource, limits=None)

    Get or set process resource limits (see
    `man prlimit <http://linux.die.net/man/2/prlimit>`__). *resource* is one
    of the :data:`psutil.RLIMIT_* <psutil.RLIMIT_INFINITY>` constants.
    *limits* is a ``(soft, hard)`` tuple.
    This is the same as `resource.getrlimit() <http://docs.python.org/library/resource.html#resource.getrlimit>`__
    and `resource.setrlimit() <http://docs.python.org/library/resource.html#resource.setrlimit>`__
    but can be used for any process PID, not only
    `os.getpid() <http://docs.python.org/library/os.html#os.getpid>`__.
    Example:

      >>> import psutil
      >>> p = psutil.Process()
      >>> # process may open no more than 128 file descriptors
      >>> p.rlimit(psutil.RLIMIT_NOFILE, (128, 128))
      >>> # process may create files no bigger than 1024 bytes
      >>> p.rlimit(psutil.RLIMIT_FSIZE, (1024, 1024))
      >>> # get
      >>> p.rlimit(psutil.RLIMIT_FSIZE)
      (1024, 1024)
      >>>

    Availability: Linux

  .. method:: io_counters()

    Return process I/O statistics as a namedtuple including the number of read
    and write operations performed by the process and the amount of bytes read
    and written. For Linux refer to
    `/proc filesysem documentation <https://www.kernel.org/doc/Documentation/filesystems/proc.txt>`__.
    On BSD there's apparently no way to retrieve bytes counters, hence ``-1``
    is returned for **read_bytes** and **write_bytes** fields. OSX is not
    supported.

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.io_counters()
      pio(read_count=454556, write_count=3456, read_bytes=110592, write_bytes=0)

    Availability: all platforms except OSX and Solaris

  .. method:: num_ctx_switches()

    The number voluntary and involuntary context switches performed by
    this process.

  .. method:: num_fds()

    The number of file descriptors used by this process.

    Availability: UNIX

  .. method:: num_handles()

    The number of handles used by this process.

    Availability: Windows

  .. method:: num_threads()

    The number of threads used by this process.

  .. method:: threads()

    Return threads opened by process as a list of namedtuples including thread
    id and thread CPU times (user/system). On OpenBSD this method requires
    root access.

  .. method:: cpu_times()

    Return a `(user, system, children_user, children_system)` namedtuple
    representing the accumulated process time, in seconds (see
    `explanation <http://stackoverflow.com/questions/556405/>`__).
    On Windows and OSX only *user* and *system* are filled, the others are
    set to ``0``.
    This is similar to
    `os.times() <http://docs.python.org//library/os.html#os.times>`__
    but can be used for any process PID.

    .. versionchanged::
      4.1.0 return two extra fields: *children_user* and *children_system*.

  .. method:: cpu_percent(interval=None)

    Return a float representing the process CPU utilization as a percentage.
    The returned value refers to the utilization of a single CPU, i.e. it is
    not evenly split between the number of available CPU cores.
    When *interval* is > ``0.0`` compares process times to system CPU times
    elapsed before and after the interval (blocking). When interval is ``0.0``
    or ``None`` compares process times to system CPU times elapsed since last
    call, returning immediately. That means the first time this is called it
    will return a meaningless ``0.0`` value which you are supposed to ignore.
    In this case is recommended for accuracy that this function be called a
    second time with at least ``0.1`` seconds between calls.
    Example:

      >>> import psutil
      >>> p = psutil.Process()
      >>>
      >>> # blocking
      >>> p.cpu_percent(interval=1)
      2.0
      >>> # non-blocking (percentage since last call)
      >>> p.cpu_percent(interval=None)
      2.9
      >>>

    .. note::
      a percentage > 100 is legitimate as it can result from a process with
      multiple threads running on different CPU cores.

    .. note::
      the returned value is explcitly **not** split evenly between all CPUs
      cores (differently from :func:`psutil.cpu_percent()`).
      This means that a busy loop process running on a system with 2 CPU
      cores will be reported as having 100% CPU utilization instead of 50%.
      This was done in order to be consistent with UNIX's "top" utility
      and also to make it easier to identify processes hogging CPU resources
      (independently from the number of CPU cores).
      It must be noted that in the example above taskmgr.exe on Windows will
      report 50% usage instead.
      To emulate Windows's taskmgr.exe behavior you can do:
      ``p.cpu_percent() / psutil.cpu_count()``.

    .. warning::
      the first time this method is called with interval = ``0.0`` or
      ``None`` it will return a meaningless ``0.0`` value which you are
      supposed to ignore.

  .. method:: cpu_affinity(cpus=None)

    Get or set process current
    `CPU affinity <http://www.linuxjournal.com/article/6799?page=0,0>`__.
    CPU affinity consists in telling the OS to run a certain process on a
    limited set of CPUs only. The number of eligible CPUs can be obtained with
    ``list(range(psutil.cpu_count()))``. ``ValueError`` will be raise on set
    in case an invalid CPU number is specified.

      >>> import psutil
      >>> psutil.cpu_count()
      4
      >>> p = psutil.Process()
      >>> p.cpu_affinity()  # get
      [0, 1, 2, 3]
      >>> p.cpu_affinity([0])  # set; from now on, process will run on CPU #0 only
      >>> p.cpu_affinity()
      [0]
      >>>
      >>> # reset affinity against all CPUs
      >>> all_cpus = list(range(psutil.cpu_count()))
      >>> p.cpu_affinity(all_cpus)
      >>>

    Availability: Linux, Windows, FreeBSD

    .. versionchanged:: 2.2.0 added support for FreeBSD

  .. method:: memory_info()

    Return a namedtuple with variable fields depending on the platform
    representing memory information about the process.
    The "portable" fields available on all plaforms are `rss` and `vms`.
    All numbers are expressed in bytes.

    +---------+---------+-------+---------+------------------------------+
    | Linux   | OSX     | BSD   | Solaris | Windows                      |
    +=========+=========+=======+=========+==============================+
    | rss     | rss     | rss   | rss     | rss (alias for ``wset``)     |
    +---------+---------+-------+---------+------------------------------+
    | vms     | vms     | vms   | vms     | vms (alias for ``pagefile``) |
    +---------+---------+-------+---------+------------------------------+
    | shared  | pfaults | text  |         | num_page_faults              |
    +---------+---------+-------+---------+------------------------------+
    | text    | pageins | data  |         | peak_wset                    |
    +---------+---------+-------+---------+------------------------------+
    | lib     |         | stack |         | wset                         |
    +---------+---------+-------+---------+------------------------------+
    | data    |         |       |         | peak_paged_pool              |
    +---------+---------+-------+---------+------------------------------+
    | dirty   |         |       |         | paged_pool                   |
    +---------+---------+-------+---------+------------------------------+
    |         |         |       |         | peak_nonpaged_pool           |
    +---------+---------+-------+---------+------------------------------+
    |         |         |       |         | nonpaged_pool                |
    +---------+---------+-------+---------+------------------------------+
    |         |         |       |         | pagefile                     |
    +---------+---------+-------+---------+------------------------------+
    |         |         |       |         | peak_pagefile                |
    +---------+---------+-------+---------+------------------------------+
    |         |         |       |         | private                      |
    +---------+---------+-------+---------+------------------------------+

    - **rss**: aka "Resident Set Size", this is the non-swapped physical
      memory a process has used.
      On UNIX it matches "top"'s RES column
      (see `doc <http://linux.die.net/man/1/top>`__).
      On Windows this is an alias for `wset` field and it matches "Mem Usage"
      column of taskmgr.exe.

    - **vms**: aka "Virtual Memory Size", this is the total amount of virtual
      memory used by the process.
      On UNIX it matches "top"'s VIRT column
      (see `doc <http://linux.die.net/man/1/top>`__).
      On Windows this is an alias for `pagefile` field and it matches
      "Mem Usage" "VM Size" column of taskmgr.exe.

    - **shared**: *(Linux)*
      memory that could be potentially shared with other processes.
      This matches "top"'s SHR column
      (see `doc <http://linux.die.net/man/1/top>`__).

    - **text** *(Linux, BSD)*:
      aka TRS (text resident set) the amount of memory devoted to
      executable code. This matches "top"'s CODE column
      (see `doc <http://linux.die.net/man/1/top>`__).

    - **data** *(Linux, BSD)*:
      aka DRS (data resident set) the amount of physical memory devoted to
      other than executable code. It matches "top"'s DATA column
      (see `doc <http://linux.die.net/man/1/top>`__).

    - **lib** *(Linux)*: the memory used by shared libraries.

    - **dirty** *(Linux)*: the number of dirty pages.

    For Windows fields rely on
    `PROCESS_MEMORY_COUNTERS_EX <http://msdn.microsoft.com/en-us/library/windows/desktop/ms684874(v=vs.85).aspx>`__ structure doc.
    Example on Linux:

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.memory_info()
      pmem(rss=15491072, vms=84025344, shared=5206016, text=2555904, lib=0, data=9891840, dirty=0)

    .. versionchanged::
      4.0.0 mutiple fields are returned, not only `rss` and `vms`.

  .. method:: memory_info_ex()

    Same as :meth:`memory_info` (deprecated).

    .. warning::
      deprecated in version 4.0.0; use :meth:`memory_info` instead.

  .. method:: memory_full_info()

    This method returns the same information as :meth:`memory_info`, plus, on
    some platform (Linux, OSX, Windows), also provides additional metrics
    (USS, PSS and swap).
    The additional metrics provide a better representation of "effective"
    process memory consumption (in case of USS) as explained in detail
    `here <http://grodola.blogspot.com/2016/02/psutil-4-real-process-memory-and-environ.html>`__.
    It does so by passing through the whole process address.
    As such it usually requires higher user privileges than
    :meth:`memory_info` and is considerably slower.
    On platforms where extra fields are not implented this simply returns the
    same metrics as :meth:`memory_info`.

    - **uss** *(Linux, OSX, Windows)*:
      aka "Unique Set Size", this is the memory which is unique to a process
      and which would be freed if the process was terminated right now.

    - **pss** *(Linux)*: aka "Proportional Set Size", is the amount of memory
      shared with other processes, accounted in a way that the amount is
      divided evenly between the processes that share it.
      I.e. if a process has 10 MBs all to itself and 10 MBs shared with
      another process its PSS will be 15 MBs.

    - **swap** *(Linux)*: amount of memory that has been swapped out to disk.

    .. note::
      `uss` is probably the most representative metric for determining how
      much memory is actually being used by a process.
      It represents the amount of memory that would be freed if the process
      was terminated right now.

    Example on Linux:

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.memory_full_info()
      pfullmem(rss=10199040, vms=52133888, shared=3887104, text=2867200, lib=0, data=5967872, dirty=0, uss=6545408, pss=6872064, swap=0)
      >>>

    See also `scripts/procsmem.py <https://github.com/giampaolo/psutil/blob/master/scripts/procsmem.py>`__
    for an example application.

    .. versionadded:: 4.0.0

  .. method:: memory_percent(memtype="rss")

    Compare process memory to total physical system memory and calculate
    process memory utilization as a percentage.
    *memtype* argument is a string that dictates what type of process memory
    you want to compare against. You can choose between the namedtuple field
    names returned by :meth:`memory_info` and :meth:`memory_full_info`
    (defaults to ``"rss"``).

    .. versionchanged:: 4.0.0 added `memtype` parameter.

  .. method:: memory_maps(grouped=True)

    Return process's mapped memory regions as a list of namedtuples whose
    fields are variable depending on the platform.
    This method is useful to obtain a detailed representation of process
    memory usage as explained
    `here <http://bmaurer.blogspot.it/2006/03/memory-usage-with-smaps.html>`__
    (the most important value is "private" memory).
    If *grouped* is ``True`` the mapped regions with the same *path* are
    grouped together and the different memory fields are summed.  If *grouped*
    is ``False`` each mapped region is shown as a single entity and the
    namedtuple will also include the mapped region's address space (*addr*)
    and permission set (*perms*).
    See `scripts/pmap.py <https://github.com/giampaolo/psutil/blob/master/scripts/pmap.py>`__
    for an example application.

    +---------------+--------------+---------+-----------+--------------+
    | Linux         |  OSX         | Windows | Solaris   | FreeBSD      |
    +===============+==============+=========+===========+==============+
    | rss           | rss          | rss     | rss       | rss          |
    +---------------+--------------+---------+-----------+--------------+
    | size          | private      |         | anonymous | private      |
    +---------------+--------------+---------+-----------+--------------+
    | pss           | swapped      |         | locked    | ref_count    |
    +---------------+--------------+---------+-----------+--------------+
    | shared_clean  | dirtied      |         |           | shadow_count |
    +---------------+--------------+---------+-----------+--------------+
    | shared_dirty  | ref_count    |         |           |              |
    +---------------+--------------+---------+-----------+--------------+
    | private_clean | shadow_depth |         |           |              |
    +---------------+--------------+---------+-----------+--------------+
    | private_dirty |              |         |           |              |
    +---------------+--------------+---------+-----------+--------------+
    | referenced    |              |         |           |              |
    +---------------+--------------+---------+-----------+--------------+
    | anonymous     |              |         |           |              |
    +---------------+--------------+---------+-----------+--------------+
    | swap          |              |         |           |              |
    +---------------+--------------+---------+-----------+--------------+

      >>> import psutil
      >>> p = psutil.Process()
      >>> p.memory_maps()
      [pmmap_grouped(path='/lib/x8664-linux-gnu/libutil-2.15.so', rss=32768, size=2125824, pss=32768, shared_clean=0, shared_dirty=0, private_clean=20480, private_dirty=12288, referenced=32768, anonymous=12288, swap=0),
       pmmap_grouped(path='/lib/x8664-linux-gnu/libc-2.15.so', rss=3821568, size=3842048, pss=3821568, shared_clean=0, shared_dirty=0, private_clean=0, private_dirty=3821568, referenced=3575808, anonymous=3821568, swap=0),
       pmmap_grouped(path='/lib/x8664-linux-gnu/libcrypto.so.0.1', rss=34124, rss=32768, size=2134016, pss=15360, shared_clean=24576, shared_dirty=0, private_clean=0, private_dirty=8192, referenced=24576, anonymous=8192, swap=0),
       pmmap_grouped(path='[heap]',  rss=32768, size=139264, pss=32768, shared_clean=0, shared_dirty=0, private_clean=0, private_dirty=32768, referenced=32768, anonymous=32768, swap=0),
       pmmap_grouped(path='[stack]', rss=2465792, size=2494464, pss=2465792, shared_clean=0, shared_dirty=0, private_clean=0, private_dirty=2465792, referenced=2277376, anonymous=2465792, swap=0),
       ...]
      >>>

    Availability: All platforms except OpenBSD and NetBSD.

  .. method:: children(recursive=False)

    Return the children of this process as a list of :Class:`Process` objects,
    preemptively checking whether PID has been reused. If recursive is `True`
    return all the parent descendants.
    Example assuming *A == this process*:
    ::

      A ─┐
         │
         ├─ B (child) ─┐
         │             └─ X (grandchild) ─┐
         │                                └─ Y (great grandchild)
         ├─ C (child)
         └─ D (child)

      >>> p.children()
      B, C, D
      >>> p.children(recursive=True)
      B, X, Y, C, D

    Note that in the example above if process X disappears process Y won't be
    returned either as the reference to process A is lost.

  .. method:: open_files()

    Return regular files opened by process as a list of namedtuples including
    the following fields:

    - **path**: the absolute file name.
    - **fd**: the file descriptor number; on Windows this is always ``-1``.
    - **position** (*Linux*): the file (offset) position.
    - **mode** (*Linux*): a string indicating how the file was opened, similarly
      `open <https://docs.python.org/3/library/functions.html#open>`__'s
      ``mode`` argument. Possible values are ``'r'``, ``'w'``, ``'a'``,
      ``'r+'`` and ``'a+'``. There's no distinction between files opened in
      bynary or text mode (``"b"`` or ``"t"``).
    - **flags** (*Linux*): the flags which were passed to the underlying
      `os.open <https://docs.python.org/2/library/os.html#os.open>`__ C call
      when the file was opened (e.g.
      `os.O_RDONLY <https://docs.python.org/3/library/os.html#os.O_RDONLY>`__,
      `os.O_TRUNC <https://docs.python.org/3/library/os.html#os.O_TRUNC>`__,
      etc).

    >>> import psutil
    >>> f = open('file.ext', 'w')
    >>> p = psutil.Process()
    >>> p.open_files()
    [popenfile(path='/home/giampaolo/svn/psutil/setup.py', fd=3, position=0, mode='r', flags=32768),
    popenfile(path='/var/log/monitd', fd=4, position=235542, mode='a', flags=33793)]

    .. warning::
      on Windows this is not fully reliable as due to some limitations of the
      Windows API the underlying implementation may hang when retrieving
      certain file handles.
      In order to work around that psutil on Windows Vista (and higher) spawns
      a thread and kills it if it's not responding after 100ms.
      That implies that on Windows this method is not guaranteed to enumerate
      all regular file handles (see full
      `discussion <https://github.com/giampaolo/psutil/pull/597>`_).

    .. warning::
      on BSD this method can return files with a 'null' path due to a kernel
      bug hence it's not reliable
      (see `issue 595 <https://github.com/giampaolo/psutil/pull/595>`_).

    .. versionchanged::
      3.1.0 no longer hangs on Windows.

    .. versionchanged::
      4.1.0 new *position*, *mode* and *flags* fields on Linux.

  .. method:: connections(kind="inet")

    Return socket connections opened by process as a list of namedtuples.
    To get system-wide connections use :func:`psutil.net_connections()`.
    Every namedtuple provides 6 attributes:

    - **fd**: the socket file descriptor. This can be passed to
      `socket.fromfd() <http://docs.python.org/library/socket.html#socket.fromfd>`__
      to obtain a usable socket object.
      This is only available on UNIX; on Windows ``-1`` is always returned.
    - **family**: the address family, either `AF_INET
      <http://docs.python.org//library/socket.html#socket.AF_INET>`__,
      `AF_INET6 <http://docs.python.org//library/socket.html#socket.AF_INET6>`__
      or `AF_UNIX <http://docs.python.org//library/socket.html#socket.AF_UNIX>`__.
    - **type**: the address type, either `SOCK_STREAM
      <http://docs.python.org//library/socket.html#socket.SOCK_STREAM>`__ or
      `SOCK_DGRAM
      <http://docs.python.org//library/socket.html#socket.SOCK_DGRAM>`__.
    - **laddr**: the local address as a ``(ip, port)`` tuple or a ``path``
      in case of AF_UNIX sockets.
    - **raddr**: the remote address as a ``(ip, port)`` tuple or an absolute
      ``path`` in case of UNIX sockets.
      When the remote endpoint is not connected you'll get an empty tuple
      (AF_INET) or ``None`` (AF_UNIX).
      On Linux AF_UNIX sockets will always have this set to ``None``.
    - **status**: represents the status of a TCP connection. The return value
      is one of the :data:`psutil.CONN_* <psutil.CONN_ESTABLISHED>` constants.
      For UDP and UNIX sockets this is always going to be
      :const:`psutil.CONN_NONE`.

    The *kind* parameter is a string which filters for connections that fit the
    following criteria:

    +----------------+-----------------------------------------------------+
    | **Kind value** | **Connections using**                               |
    +================+=====================================================+
    | "inet"         | IPv4 and IPv6                                       |
    +----------------+-----------------------------------------------------+
    | "inet4"        | IPv4                                                |
    +----------------+-----------------------------------------------------+
    | "inet6"        | IPv6                                                |
    +----------------+-----------------------------------------------------+
    | "tcp"          | TCP                                                 |
    +----------------+-----------------------------------------------------+
    | "tcp4"         | TCP over IPv4                                       |
    +----------------+-----------------------------------------------------+
    | "tcp6"         | TCP over IPv6                                       |
    +----------------+-----------------------------------------------------+
    | "udp"          | UDP                                                 |
    +----------------+-----------------------------------------------------+
    | "udp4"         | UDP over IPv4                                       |
    +----------------+-----------------------------------------------------+
    | "udp6"         | UDP over IPv6                                       |
    +----------------+-----------------------------------------------------+
    | "unix"         | UNIX socket (both UDP and TCP protocols)            |
    +----------------+-----------------------------------------------------+
    | "all"          | the sum of all the possible families and protocols  |
    +----------------+-----------------------------------------------------+

    Example:

      >>> import psutil
      >>> p = psutil.Process(1694)
      >>> p.name()
      'firefox'
      >>> p.connections()
      [pconn(fd=115, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 48776), raddr=('93.186.135.91', 80), status='ESTABLISHED'),
       pconn(fd=117, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 43761), raddr=('72.14.234.100', 80), status='CLOSING'),
       pconn(fd=119, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 60759), raddr=('72.14.234.104', 80), status='ESTABLISHED'),
       pconn(fd=123, family=<AddressFamily.AF_INET: 2>, type=<SocketType.SOCK_STREAM: 1>, laddr=('10.0.0.1', 51314), raddr=('72.14.234.83', 443), status='SYN_SENT')]

  .. method:: is_running()

    Return whether the current process is running in the current process list.
    This is reliable also in case the process is gone and its PID reused by
    another process, therefore it must be preferred over doing
    ``psutil.pid_exists(p.pid)``.

    .. note::
      this will return ``True`` also if the process is a zombie
      (``p.status() == psutil.STATUS_ZOMBIE``).

  .. method:: send_signal(signal)

    Send a signal to process (see
    `signal module <http://docs.python.org//library/signal.html>`__
    constants) preemptively checking whether PID has been reused.
    On UNIX this is the same as ``os.kill(pid, sig)``.
    On Windows only **SIGTERM**, **CTRL_C_EVENT** and **CTRL_BREAK_EVENT**
    signals are supported and **SIGTERM** is treated as an alias for
    :meth:`kill()`.

    .. versionchanged::
      3.2.0 support for CTRL_C_EVENT and CTRL_BREAK_EVENT signals on Windows
      was added.

  .. method:: suspend()

    Suspend process execution with **SIGSTOP** signal preemptively checking
    whether PID has been reused.
    On UNIX this is the same as ``os.kill(pid, signal.SIGSTOP)``.
    On Windows this is done by suspending all process threads execution.

  .. method:: resume()

    Resume process execution with **SIGCONT** signal preemptively checking
    whether PID has been reused.
    On UNIX this is the same as ``os.kill(pid, signal.SIGCONT)``.
    On Windows this is done by resuming all process threads execution.

  .. method:: terminate()

    Terminate the process with **SIGTERM** signal preemptively checking
    whether PID has been reused.
    On UNIX this is the same as ``os.kill(pid, signal.SIGTERM)``.
    On Windows this is an alias for :meth:`kill`.

  .. method:: kill()

     Kill the current process by using **SIGKILL** signal preemptively
     checking whether PID has been reused.
     On UNIX this is the same as ``os.kill(pid, signal.SIGKILL)``.
     On Windows this is done by using
     `TerminateProcess <http://msdn.microsoft.com/en-us/library/windows/desktop/ms686714(v=vs.85).aspx>`__.

  .. method:: wait(timeout=None)

    Wait for process termination and if the process is a children of the
    current one also return the exit code, else ``None``. On Windows there's
    no such limitation (exit code is always returned). If the process is
    already terminated immediately return ``None`` instead of raising
    :class:`NoSuchProcess`. If *timeout* is specified and process is still
    alive raise :class:`TimeoutExpired` exception. It can also be used in a
    non-blocking fashion by specifying ``timeout=0`` in which case it will
    either return immediately or raise :class:`TimeoutExpired`.
    To wait for multiple processes use :func:`psutil.wait_procs()`.


Popen class
-----------

.. class:: Popen(*args, **kwargs)

  A more convenient interface to stdlib
  `subprocess.Popen <http://docs.python.org/library/subprocess.html#subprocess.Popen>`__.
  It starts a sub process and deals with it exactly as when using
  `subprocess.Popen <http://docs.python.org/library/subprocess.html#subprocess.Popen>`__
  but in addition it also provides all the methods of
  :class:`psutil.Process` class in a single interface.
  For method names common to both classes such as
  :meth:`send_signal() <psutil.Process.send_signal()>`,
  :meth:`terminate() <psutil.Process.terminate()>` and
  :meth:`kill() <psutil.Process.kill()>`
  :class:`psutil.Process` implementation takes precedence.
  For a complete documentation refer to
  `subprocess module documentation <http://docs.python.org/library/subprocess.html>`__.

  .. note::

    Unlike `subprocess.Popen <http://docs.python.org/library/subprocess.html#subprocess.Popen>`__
    this class preemptively checks wheter PID has been reused on
    :meth:`send_signal() <psutil.Process.send_signal()>`,
    :meth:`terminate() <psutil.Process.terminate()>` and
    :meth:`kill() <psutil.Process.kill()>`
    so that you can't accidentally terminate another process, fixing
    http://bugs.python.org/issue6973.

  >>> import psutil
  >>> from subprocess import PIPE
  >>>
  >>> p = psutil.Popen(["/usr/bin/python", "-c", "print('hello')"], stdout=PIPE)
  >>> p.name()
  'python'
  >>> p.username()
  'giampaolo'
  >>> p.communicate()
  ('hello\n', None)
  >>> p.wait(timeout=2)
  0
  >>>

Windows services
================

.. function:: win_service_iter()

  Return an iterator yielding a :class:`WindowsService` class instance for all
  Windows services installed.

  .. versionadded:: 4.2.0

  Availability: Windows

.. function:: win_service_get(name)

  Get a Windows service by name, returning a :class:`WindowsService` instance.
  Raise :class:`psutil.NoSuchProcess` if no service with such name exists.

  .. versionadded:: 4.2.0

  Availability: Windows

.. class:: WindowsService

  Represents a Windows service with the given *name*. This class is returned
  by :func:`win_service_iter` and :func:`win_service_get` functions and it is
  not supposed to be instantiated directly.

  .. method:: name()

    The service name. This string is how a service is referenced and can be
    passed to :func:`win_service_get` to get a new :class:`WindowsService`
    instance.

  .. method:: display_name()

    The service display name. The value is cached when this class is
    instantiated.

  .. method:: binpath()

    The fully qualified path to the service binary/exe file as a string,
    including command line arguments.

  .. method:: username()

    The name of the user that owns this service.

  .. method:: start_type()

    A string which can either be `"automatic"`, `"manual"` or `"disabled"`.

  .. method:: pid()

    The process PID, if any, else `None`. This can be passed to
    :class:`Process` class to control the service's process.

  .. method:: status()

    Service status as a string, which may be either `"running"`, `"paused"`,
    `"start_pending"`, `"pause_pending"`, `"continue_pending"`,
    `"stop_pending"` or `"stopped"`.

  .. method:: description()

    Service long description.

  .. method:: as_dict()

    Utility method retrieving all the information above as a dictionary.

  .. versionadded:: 4.2.0

  Availability: Windows

Example code:

  >>> import psutil
  >>> list(psutil.win_service_iter())
  [<WindowsService(name='AeLookupSvc', display_name='Application Experience') at 38850096>,
   <WindowsService(name='ALG', display_name='Application Layer Gateway Service') at 38850128>,
   <WindowsService(name='APNMCP', display_name='Ask Update Service') at 38850160>,
   <WindowsService(name='AppIDSvc', display_name='Application Identity') at 38850192>,
   ...]
  >>> s = psutil.win_service_get('alg')
  >>> s.as_dict()
  {'binpath': 'C:\\Windows\\System32\\alg.exe',
   'description': 'Provides support for 3rd party protocol plug-ins for Internet Connection Sharing',
   'display_name': 'Application Layer Gateway Service',
   'name': 'alg',
   'pid': None,
   'start_type': 'manual',
   'status': 'stopped',
   'username': 'NT AUTHORITY\\LocalService'}

Constants
=========

.. _const-oses:
.. data:: POSIX
          WINDOWS
          LINUX
          OSX
          FREEBSD
          NETBSD
          OPENBSD
          BSD
          SUNOS

  ``bool`` constants which define what platform you're on. E.g. if on Windows,
  *WINDOWS* constant will be ``True``, all others will be ``False``.

  .. versionadded:: 4.0.0

.. _const-procfs_path:
.. data:: PROCFS_PATH

  The path of the /proc filesystem on Linux and Solaris (defaults to "/proc").
  You may want to re-set this constant right after importing psutil in case
  your /proc filesystem is mounted elsewhere.

  Availability: Linux, Solaris

  .. versionadded:: 3.2.3
  .. versionchanged:: 3.4.2 also available on Solaris.

.. _const-pstatus:
.. data:: STATUS_RUNNING
          STATUS_SLEEPING
          STATUS_DISK_SLEEP
          STATUS_STOPPED
          STATUS_TRACING_STOP
          STATUS_ZOMBIE
          STATUS_DEAD
          STATUS_WAKE_KILL
          STATUS_WAKING
          STATUS_IDLE (OSX, FreeBSD)
          STATUS_LOCKED (FreeBSD)
          STATUS_WAITING (FreeBSD)
          STATUS_SUSPENDED (NetBSD)

  A set of strings representing the status of a process.
  Returned by :meth:`psutil.Process.status()`.

  .. versionadded:: 3.4.1 STATUS_SUSPENDED (NetBSD)

.. _const-conn:
.. data:: CONN_ESTABLISHED
          CONN_SYN_SENT
          CONN_SYN_RECV
          CONN_FIN_WAIT1
          CONN_FIN_WAIT2
          CONN_TIME_WAIT
          CONN_CLOSE
          CONN_CLOSE_WAIT
          CONN_LAST_ACK
          CONN_LISTEN
          CONN_CLOSING
          CONN_NONE
          CONN_DELETE_TCB (Windows)
          CONN_IDLE (Solaris)
          CONN_BOUND (Solaris)

  A set of strings representing the status of a TCP connection.
  Returned by :meth:`psutil.Process.connections()` (`status` field).

.. _const-prio:
.. data:: ABOVE_NORMAL_PRIORITY_CLASS
          BELOW_NORMAL_PRIORITY_CLASS
          HIGH_PRIORITY_CLASS
          IDLE_PRIORITY_CLASS
          NORMAL_PRIORITY_CLASS
          REALTIME_PRIORITY_CLASS

  A set of integers representing the priority of a process on Windows (see
  `MSDN documentation <http://msdn.microsoft.com/en-us/library/ms686219(v=vs.85).aspx>`__).
  They can be used in conjunction with
  :meth:`psutil.Process.nice()` to get or set process priority.

  Availability: Windows

  .. versionchanged::
    3.0.0 on Python >= 3.4 these constants are
    `enums <https://docs.python.org/3/library/enum.html#module-enum>`__
    instead of a plain integer.

.. _const-ioprio:
.. data:: IOPRIO_CLASS_NONE
          IOPRIO_CLASS_RT
          IOPRIO_CLASS_BE
          IOPRIO_CLASS_IDLE

  A set of integers representing the I/O priority of a process on Linux. They
  can be used in conjunction with :meth:`psutil.Process.ionice()` to get or set
  process I/O priority.
  *IOPRIO_CLASS_NONE* and *IOPRIO_CLASS_BE* (best effort) is the default for
  any process that hasn't set a specific I/O priority.
  *IOPRIO_CLASS_RT* (real time) means the process is given first access to the
  disk, regardless of what else is going on in the system.
  *IOPRIO_CLASS_IDLE* means the process will get I/O time when no-one else
  needs the disk.
  For further information refer to manuals of
  `ionice <http://linux.die.net/man/1/ionice>`__
  command line utility or
  `ioprio_get <http://linux.die.net/man/2/ioprio_get>`__
  system call.

  Availability: Linux

  .. versionchanged::
    3.0.0 on Python >= 3.4 thse constants are
    `enums <https://docs.python.org/3/library/enum.html#module-enum>`__
    instead of a plain integer.

.. _const-rlimit:
.. data:: RLIMIT_INFINITY
          RLIMIT_AS
          RLIMIT_CORE
          RLIMIT_CPU
          RLIMIT_DATA
          RLIMIT_FSIZE
          RLIMIT_LOCKS
          RLIMIT_MEMLOCK
          RLIMIT_MSGQUEUE
          RLIMIT_NICE
          RLIMIT_NOFILE
          RLIMIT_NPROC
          RLIMIT_RSS
          RLIMIT_RTPRIO
          RLIMIT_RTTIME
          RLIMIT_RTPRIO
          RLIMIT_SIGPENDING
          RLIMIT_STACK

  Constants used for getting and setting process resource limits to be used in
  conjunction with :meth:`psutil.Process.rlimit()`. See
  `man prlimit <http://linux.die.net/man/2/prlimit>`__ for further information.

  Availability: Linux

.. _const-aflink:
.. data:: AF_LINK

  Constant which identifies a MAC address associated with a network interface.
  To be used in conjunction with :func:`psutil.net_if_addrs()`.

  .. versionadded:: 3.0.0

.. _const-duplex:
.. data:: NIC_DUPLEX_FULL
          NIC_DUPLEX_HALF
          NIC_DUPLEX_UNKNOWN

  Constants which identifies whether a NIC (network interface card) has full or
  half mode speed.  NIC_DUPLEX_FULL means the NIC is able to send and receive
  data (files) simultaneously, NIC_DUPLEX_FULL means the NIC can either send or
  receive data at a time.
  To be used in conjunction with :func:`psutil.net_if_stats()`.

  .. versionadded:: 3.0.0

Development guide
=================

If you plan on hacking on psutil (e.g. want to add a new feature or fix a bug)
take a look at the
`development guide <https://github.com/giampaolo/psutil/blob/master/DEVGUIDE.rst>`_.
