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# 15.14. `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 pretty 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

`errno.``ENOENT`
  No such file or directory

`errno.``ESRCH`
  No such process

`errno.``EINTR`
  Interrupted system call

`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

`errno.``EAGAIN`
  Try again

`errno.``ENOMEM`
  Out of memory

`errno.``EACCES`
  Permission denied

`errno.``EFAULT`
  Bad address

`errno.``ENOTBLK`
  Block device required

`errno.``EBUSY`
  Device or resource busy

`errno.``EEXIST`
  File exists

`errno.``EXDEV`
  Cross-device link

`errno.``ENODEV`
  No such device

`errno.``ENOTDIR`
  Not a directory

`errno.``EISDIR`
  Is a directory

`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

`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

`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

`errno.``ECONNRESET`
  Connection reset by peer

`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

`errno.``ETOOMANYREFS`
  Too many references: cannot splice

`errno.``ETIMEDOUT`
  Connection timed out

`errno.``ECONNREFUSED`
  Connection refused

`errno.``EHOSTDOWN`
  Host is down

`errno.``EHOSTUNREACH`
  No route to host

`errno.``EALREADY`
  Operation already in progress

`errno.``EINPROGRESS`
  Operation now in progress

`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

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