.. module:: errno
   :synopsis: Standard errno system symbols.

This module makes available standard errno system symbols. The value of each symbol is the corresponding integer value. The names and descriptions are borrowed from :file:`linux/include/errno.h`, which should be all-inclusive.

.. data:: errorcode

   Dictionary providing a mapping from the errno value to the string name in the
   underlying system.  For instance, ``errno.errorcode[errno.EPERM]`` maps to
   ``'EPERM'``.

To translate a numeric error code to an error message, use :func:`os.strerror`.

Of the following list, symbols that are not used on the current platform are not defined by the module. The specific list of defined symbols is available as errno.errorcode.keys(). Symbols available can include:

.. data:: EPERM

   Operation not permitted. This error is mapped to the exception
   :exc:`PermissionError`.

.. data:: ENOENT

   No such file or directory. This error is mapped to the exception
   :exc:`FileNotFoundError`.

.. data:: ESRCH

   No such process. This error is mapped to the exception
   :exc:`ProcessLookupError`.

.. data:: EINTR

   Interrupted system call. This error is mapped to the exception
   :exc:`InterruptedError`.

.. data:: EIO

   I/O error

.. data:: ENXIO

   No such device or address

.. data:: E2BIG

   Arg list too long

.. data:: ENOEXEC

   Exec format error

.. data:: EBADF

   Bad file number

.. data:: ECHILD

   No child processes. This error is mapped to the exception
   :exc:`ChildProcessError`.

.. data:: EAGAIN

   Try again. This error is mapped to the exception :exc:`BlockingIOError`.

.. data:: ENOMEM

   Out of memory

.. data:: EACCES

   Permission denied.  This error is mapped to the exception
   :exc:`PermissionError`.

.. data:: EFAULT

   Bad address

.. data:: ENOTBLK

   Block device required

.. data:: EBUSY

   Device or resource busy

.. data:: EEXIST

   File exists. This error is mapped to the exception
   :exc:`FileExistsError`.

.. data:: EXDEV

   Cross-device link

.. data:: ENODEV

   No such device

.. data:: ENOTDIR

   Not a directory. This error is mapped to the exception
   :exc:`NotADirectoryError`.

.. data:: EISDIR

   Is a directory. This error is mapped to the exception
   :exc:`IsADirectoryError`.

.. data:: EINVAL

   Invalid argument

.. data:: ENFILE

   File table overflow

.. data:: EMFILE

   Too many open files

.. data:: ENOTTY

   Not a typewriter

.. data:: ETXTBSY

   Text file busy

.. data:: EFBIG

   File too large

.. data:: ENOSPC

   No space left on device

.. data:: ESPIPE

   Illegal seek

.. data:: EROFS

   Read-only file system

.. data:: EMLINK

   Too many links

.. data:: EPIPE

   Broken pipe. This error is mapped to the exception
   :exc:`BrokenPipeError`.

.. data:: EDOM

   Math argument out of domain of func

.. data:: ERANGE

   Math result not representable

.. data:: EDEADLK

   Resource deadlock would occur

.. data:: ENAMETOOLONG

   File name too long

.. data:: ENOLCK

   No record locks available

.. data:: ENOSYS

   Function not implemented

.. data:: ENOTEMPTY

   Directory not empty

.. data:: ELOOP

   Too many symbolic links encountered

.. data:: EWOULDBLOCK

   Operation would block. This error is mapped to the exception
   :exc:`BlockingIOError`.

.. data:: ENOMSG

   No message of desired type

.. data:: EIDRM

   Identifier removed

.. data:: ECHRNG

   Channel number out of range

.. data:: EL2NSYNC

   Level 2 not synchronized

.. data:: EL3HLT

   Level 3 halted

.. data:: EL3RST

   Level 3 reset

.. data:: ELNRNG

   Link number out of range

.. data:: EUNATCH

   Protocol driver not attached

.. data:: ENOCSI

   No CSI structure available

.. data:: EL2HLT

   Level 2 halted

.. data:: EBADE

   Invalid exchange

.. data:: EBADR

   Invalid request descriptor

.. data:: EXFULL

   Exchange full

.. data:: ENOANO

   No anode

.. data:: EBADRQC

   Invalid request code

.. data:: EBADSLT

   Invalid slot

.. data:: EDEADLOCK

   File locking deadlock error

.. data:: EBFONT

   Bad font file format

.. data:: ENOSTR

   Device not a stream

.. data:: ENODATA

   No data available

.. data:: ETIME

   Timer expired

.. data:: ENOSR

   Out of streams resources

.. data:: ENONET

   Machine is not on the network

.. data:: ENOPKG

   Package not installed

.. data:: EREMOTE

   Object is remote

.. data:: ENOLINK

   Link has been severed

.. data:: EADV

   Advertise error

.. data:: ESRMNT

   Srmount error

.. data:: ECOMM

   Communication error on send

.. data:: EPROTO

   Protocol error

.. data:: EMULTIHOP

   Multihop attempted

.. data:: EDOTDOT

   RFS specific error

.. data:: EBADMSG

   Not a data message

.. data:: EOVERFLOW

   Value too large for defined data type

.. data:: ENOTUNIQ

   Name not unique on network

.. data:: EBADFD

   File descriptor in bad state

.. data:: EREMCHG

   Remote address changed

.. data:: ELIBACC

   Can not access a needed shared library

.. data:: ELIBBAD

   Accessing a corrupted shared library

.. data:: ELIBSCN

   .lib section in a.out corrupted

.. data:: ELIBMAX

   Attempting to link in too many shared libraries

.. data:: ELIBEXEC

   Cannot exec a shared library directly

.. data:: EILSEQ

   Illegal byte sequence

.. data:: ERESTART

   Interrupted system call should be restarted

.. data:: ESTRPIPE

   Streams pipe error

.. data:: EUSERS

   Too many users

.. data:: ENOTSOCK

   Socket operation on non-socket

.. data:: EDESTADDRREQ

   Destination address required

.. data:: EMSGSIZE

   Message too long

.. data:: EPROTOTYPE

   Protocol wrong type for socket

.. data:: ENOPROTOOPT

   Protocol not available

.. data:: EPROTONOSUPPORT

   Protocol not supported

.. data:: ESOCKTNOSUPPORT

   Socket type not supported

.. data:: EOPNOTSUPP

   Operation not supported on transport endpoint

.. data:: ENOTSUP

   Operation not supported

   .. versionadded:: 3.2

.. data:: EPFNOSUPPORT

   Protocol family not supported

.. data:: EAFNOSUPPORT

   Address family not supported by protocol

.. data:: EADDRINUSE

   Address already in use

.. data:: EADDRNOTAVAIL

   Cannot assign requested address

.. data:: ENETDOWN

   Network is down

.. data:: ENETUNREACH

   Network is unreachable

.. data:: ENETRESET

   Network dropped connection because of reset

.. data:: ECONNABORTED

   Software caused connection abort. This error is mapped to the
   exception :exc:`ConnectionAbortedError`.

.. data:: ECONNRESET

   Connection reset by peer. This error is mapped to the exception
   :exc:`ConnectionResetError`.

.. data:: ENOBUFS

   No buffer space available

.. data:: EISCONN

   Transport endpoint is already connected

.. data:: ENOTCONN

   Transport endpoint is not connected

.. data:: ESHUTDOWN

   Cannot send after transport endpoint shutdown. This error is mapped
   to the exception :exc:`BrokenPipeError`.

.. data:: ETOOMANYREFS

   Too many references: cannot splice

.. data:: ETIMEDOUT

   Connection timed out. This error is mapped to the exception
   :exc:`TimeoutError`.

.. data:: ECONNREFUSED

   Connection refused. This error is mapped to the exception
   :exc:`ConnectionRefusedError`.

.. data:: EHOSTDOWN

   Host is down

.. data:: EHOSTUNREACH

   No route to host

.. data:: EALREADY

   Operation already in progress. This error is mapped to the
   exception :exc:`BlockingIOError`.

.. data:: EINPROGRESS

   Operation now in progress. This error is mapped to the exception
   :exc:`BlockingIOError`.

.. data:: ESTALE

   Stale NFS file handle

.. data:: EUCLEAN

   Structure needs cleaning

.. data:: ENOTNAM

   Not a XENIX named type file

.. data:: ENAVAIL

   No XENIX semaphores available

.. data:: EISNAM

   Is a named type file

.. data:: EREMOTEIO

   Remote I/O error

.. data:: EDQUOT

   Quota exceeded

.. data:: EQFULL

   Interface output queue is full

   .. versionadded:: 3.11

.. data:: ENOTCAPABLE

   Capabilities insufficient. This error is mapped to the exception
   :exc:`PermissionError`.

   .. availability:: WASI, FreeBSD

   .. versionadded:: 3.11.1

.. data:: ECANCELED

   Operation canceled

   .. versionadded:: 3.2

.. data:: EOWNERDEAD

   Owner died

   .. versionadded:: 3.2

.. data:: ENOTRECOVERABLE

   State not recoverable

   .. versionadded:: 3.2