# 6.20 `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.

`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:

`EPERM`
  Operation not permitted

`ENOENT`
  No such file or directory

`ESRCH`
  No such process

`EINTR`
  Interrupted system call

`EIO`
  I/O error

`ENXIO`
  No such device or address

`E2BIG`
  Arg list too long

`ENOEXEC`
  Exec format error

`EBADF`
  Bad file number

`ECHILD`
  No child processes

`EAGAIN`
  Try again

`ENOMEM`
  Out of memory

`EACCES`
  Permission denied

`EFAULT`
  Bad address

`ENOTBLK`
  Block device required

`EBUSY`
  Device or resource busy

`EEXIST`
  File exists

`EXDEV`
  Cross-device link

`ENODEV`
  No such device

`ENOTDIR`
  Not a directory

`EISDIR`
  Is a directory

`EINVAL`
  Invalid argument

`ENFILE`
  File table overflow

`EMFILE`
  Too many open files

`ENOTTY`
  Not a typewriter

`ETXTBSY`
  Text file busy

`EFBIG`
  File too large

`ENOSPC`
  No space left on device

`ESPIPE`
  Illegal seek

`EROFS`
  Read-only file system

`EMLINK`
  Too many links

`EPIPE`
  Broken pipe

`EDOM`
  Math argument out of domain of func

`ERANGE`
  Math result not representable

`EDEADLK`
  Resource deadlock would occur

`ENAMETOOLONG`
  File name too long

`ENOLCK`
  No record locks available

`ENOSYS`
  Function not implemented

`ENOTEMPTY`
  Directory not empty

`ELOOP`
  Too many symbolic links encountered

`EWOULDBLOCK`
  Operation would block

`ENOMSG`
  No message of desired type

`EIDRM`
  Identifier removed

`ECHRNG`
  Channel number out of range

`EL2NSYNC`
  Level 2 not synchronized

`EL3HLT`
  Level 3 halted

`EL3RST`
  Level 3 reset

`ELNRNG`
  Link number out of range

`EUNATCH`
  Protocol driver not attached

`ENOCSI`
  No CSI structure available

`EL2HLT`
  Level 2 halted

`EBADE`
  Invalid exchange

`EBADR`
  Invalid request descriptor

`EXFULL`
  Exchange full

`ENOANO`
  No anode

`EBADRQC`
  Invalid request code

`EBADSLT`
  Invalid slot

`EDEADLOCK`
  File locking deadlock error

`EBFONT`
  Bad font file format

`ENOSTR`
  Device not a stream

`ENODATA`
  No data available

`ETIME`
  Timer expired

`ENOSR`
  Out of streams resources

`ENONET`
  Machine is not on the network

`ENOPKG`
  Package not installed

`EREMOTE`
  Object is remote

`ENOLINK`
  Link has been severed

`EADV`
  Advertise error

`ESRMNT`
  Srmount error

`ECOMM`
  Communication error on send

`EPROTO`
  Protocol error

`EMULTIHOP`
  Multihop attempted

`EDOTDOT`
  RFS specific error

`EBADMSG`
  Not a data message

`EOVERFLOW`
  Value too large for defined data type

`ENOTUNIQ`
  Name not unique on network

`EBADFD`
  File descriptor in bad state

`EREMCHG`
  Remote address changed

`ELIBACC`
  Can not access a needed shared library

`ELIBBAD`
  Accessing a corrupted shared library

`ELIBSCN`
  .lib section in a.out corrupted

`ELIBMAX`
  Attempting to link in too many shared libraries

`ELIBEXEC`
  Cannot exec a shared library directly

`EILSEQ`
  Illegal byte sequence

`ERESTART`
  Interrupted system call should be restarted

`ESTRPIPE`
  Streams pipe error

`EUSERS`
  Too many users

`ENOTSOCK`
  Socket operation on non-socket

`EDESTADDRREQ`
  Destination address required

`EMSGSIZE`
  Message too long

`EPROTOTYPE`
  Protocol wrong type for socket

`ENOPROTOOPT`
  Protocol not available

`EPROTONOSUPPORT`
  Protocol not supported

`ESOCKTNOSUPPORT`
  Socket type not supported

`EOPNOTSUPP`
  Operation not supported on transport endpoint

`EPFNOSUPPORT`
  Protocol family not supported

`EAFNOSUPPORT`
  Address family not supported by protocol

`EADDRINUSE`
  Address already in use

`EADDRNOTAVAIL`
  Cannot assign requested address

`ENETDOWN`
  Network is down

`ENETUNREACH`
  Network is unreachable

`ENETRESET`
  Network dropped connection because of reset

`ECONNABORTED`
  Software caused connection abort

`ECONNRESET`
  Connection reset by peer

`ENOBUFS`
  No buffer space available

`EISCONN`
  Transport endpoint is already connected

`ENOTCONN`
  Transport endpoint is not connected

`ESHUTDOWN`
  Cannot send after transport endpoint shutdown

`ETOOMANYREFS`
  Too many references: cannot splice

`ETIMEDOUT`
  Connection timed out

`ECONNREFUSED`
  Connection refused

`EHOSTDOWN`
  Host is down

`EHOSTUNREACH`
  No route to host

`EALREADY`
  Operation already in progress

`EINPROGRESS`
  Operation now in progress

`ESTALE`
  Stale NFS file handle

`EUCLEAN`
  Structure needs cleaning

`ENOTNAM`
  Not a XENIX named type file

`ENAVAIL`
  No XENIX semaphores available

`EISNAM`
  Is a named type file

`EREMOTEIO`
  Remote I/O error

`EDQUOT`
  Quota exceeded