# `errno` — 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 `linux/include/errno.h`, which should be all-inclusive.

errno.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 `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:

errno.EPERM

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

errno.ENOENT

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

errno.ESRCH

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

errno.EINTR

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

errno.EIO

  I/O error

errno.ENXIO

  No such device or address

errno.E2BIG

  Arg list too long

errno.ENOEXEC

  Exec format error

errno.EBADF

  Bad file number

errno.ECHILD

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

errno.EAGAIN

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

errno.ENOMEM

  Out of memory

errno.EACCES

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

errno.EFAULT

  Bad address

errno.ENOTBLK

  Block device required

errno.EBUSY

  Device or resource busy

errno.EEXIST

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

errno.EXDEV

  Cross-device link

errno.ENODEV

  No such device

errno.ENOTDIR

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

errno.EISDIR

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

errno.EINVAL

  Invalid argument

errno.ENFILE

  File table overflow

errno.EMFILE

  Too many open files

errno.ENOTTY

  Not a typewriter

errno.ETXTBSY

  Text file busy

errno.EFBIG

  File too large

errno.ENOSPC

  No space left on device

errno.ESPIPE

  Illegal seek

errno.EROFS

  Read-only file system

errno.EMLINK

  Too many links

errno.EPIPE

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

errno.EDOM

  Math argument out of domain of func

errno.ERANGE

  Math result not representable

errno.EDEADLK

  Resource deadlock would occur

errno.ENAMETOOLONG

  File name too long

errno.ENOLCK

  No record locks available

errno.ENOSYS

  Function not implemented

errno.ENOTEMPTY

  Directory not empty

errno.ELOOP

  Too many symbolic links encountered

errno.EWOULDBLOCK

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

errno.ENOMSG

  No message of desired type

errno.EIDRM

  Identifier removed

errno.ECHRNG

  Channel number out of range

errno.EL2NSYNC

  Level 2 not synchronized

errno.EL3HLT

  Level 3 halted

errno.EL3RST

  Level 3 reset

errno.ELNRNG

  Link number out of range

errno.EUNATCH

  Protocol driver not attached

errno.ENOCSI

  No CSI structure available

errno.EL2HLT

  Level 2 halted

errno.EBADE

  Invalid exchange

errno.EBADR

  Invalid request descriptor

errno.EXFULL

  Exchange full

errno.ENOANO

  No anode

errno.EBADRQC

  Invalid request code

errno.EBADSLT

  Invalid slot

errno.EDEADLOCK

  File locking deadlock error

errno.EBFONT

  Bad font file format

errno.ENOSTR

  Device not a stream

errno.ENODATA

  No data available

errno.ETIME

  Timer expired

errno.ENOSR

  Out of streams resources

errno.ENONET

  Machine is not on the network

errno.ENOPKG

  Package not installed

errno.EREMOTE

  Object is remote

errno.ENOLINK

  Link has been severed

errno.EADV

  Advertise error

errno.ESRMNT

  Srmount error

errno.ECOMM

  Communication error on send

errno.EPROTO

  Protocol error

errno.EMULTIHOP

  Multihop attempted

errno.EDOTDOT

  RFS specific error

errno.EBADMSG

  Not a data message

errno.EOVERFLOW

  Value too large for defined data type

errno.ENOTUNIQ

  Name not unique on network

errno.EBADFD

  File descriptor in bad state

errno.EREMCHG

  Remote address changed

errno.ELIBACC

  Can not access a needed shared library

errno.ELIBBAD

  Accessing a corrupted shared library

errno.ELIBSCN

  .lib section in a.out corrupted

errno.ELIBMAX

  Attempting to link in too many shared libraries

errno.ELIBEXEC

  Cannot exec a shared library directly

errno.EILSEQ

  Illegal byte sequence

errno.ERESTART

  Interrupted system call should be restarted

errno.ESTRPIPE

  Streams pipe error

errno.EUSERS

  Too many users

errno.ENOTSOCK

  Socket operation on non-socket

errno.EDESTADDRREQ

  Destination address required

errno.EMSGSIZE

  Message too long

errno.EPROTOTYPE

  Protocol wrong type for socket

errno.ENOPROTOOPT

  Protocol not available

errno.EPROTONOSUPPORT

  Protocol not supported

errno.ESOCKTNOSUPPORT

  Socket type not supported

errno.EOPNOTSUPP

  Operation not supported on transport endpoint

errno.EPFNOSUPPORT

  Protocol family not supported

errno.EAFNOSUPPORT

  Address family not supported by protocol

errno.EADDRINUSE

  Address already in use

errno.EADDRNOTAVAIL

  Cannot assign requested address

errno.ENETDOWN

  Network is down

errno.ENETUNREACH

  Network is unreachable

errno.ENETRESET

  Network dropped connection because of reset

errno.ECONNABORTED

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

errno.ECONNRESET

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

errno.ENOBUFS

  No buffer space available

errno.EISCONN

  Transport endpoint is already connected

errno.ENOTCONN

  Transport endpoint is not connected

errno.ESHUTDOWN

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

errno.ETOOMANYREFS

  Too many references: cannot splice

errno.ETIMEDOUT

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

errno.ECONNREFUSED

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

errno.EHOSTDOWN

  Host is down

errno.EHOSTUNREACH

  No route to host

errno.EALREADY

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

errno.EINPROGRESS

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

errno.ESTALE

  Stale NFS file handle

errno.EUCLEAN

  Structure needs cleaning

errno.ENOTNAM

  Not a XENIX named type file

errno.ENAVAIL

  No XENIX semaphores available

errno.EISNAM

  Is a named type file

errno.EREMOTEIO

  Remote I/O error

errno.EDQUOT

  Quota exceeded

errno.EQFULL

  Interface output queue is full

  New in version 3.11.

errno.ENOTCAPABLE

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

  Availability: WASI, FreeBSD

  New in version 3.11.1.