errno.h - system error numbers

#include <errno.h>

Some of the functionality described on this reference page extends the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to the ISO C standard.

The ISO C standard only requires the symbols [EDOM], [EILSEQ], and [ERANGE] to be defined.

The <errno.h> header shall provide a declaration for errno and give positive values for the following symbolic constants. Their values shall be unique except as noted below.

E2BIG

Argument list too long.

EACCES

Permission denied.

EADDRINUSE

Address in use.

EADDRNOTAVAIL

Address not available.

EAFNOSUPPORT

Address family not supported.

EAGAIN

Resource unavailable, try again (may be the same value as [EWOULDBLOCK]).

EALREADY

Connection already in progress.

EBADF

Bad file descriptor.

EBADMSG

Bad message.

EBUSY

Device or resource busy.

ECANCELED

Operation canceled.

ECHILD

No child processes.

ECONNABORTED

Connection aborted.

ECONNREFUSED

Connection refused.

ECONNRESET

Connection reset.

EDEADLK

Resource deadlock would occur.

EDESTADDRREQ

Destination address required.

EDOM

Mathematics argument out of domain of function.

EDQUOT

Reserved.

EEXIST

File exists.

EFAULT

Bad address.

EFBIG

File too large.

EHOSTUNREACH

Host is unreachable.

EIDRM

Identifier removed.

EILSEQ

Illegal byte sequence.

EINPROGRESS

Operation in progress.

EINTR

Interrupted function.

EINVAL

Invalid argument.

EIO

I/O error.

EISCONN

Socket is connected.

EISDIR

Is a directory.

ELOOP

Too many levels of symbolic links.

EMFILE

Too many open files.

EMLINK

Too many links.

EMSGSIZE

Message too large.

EMULTIHOP

Reserved.

ENAMETOOLONG

Filename too long.

ENETDOWN

Network is down.

ENETRESET

Connection aborted by network.

ENETUNREACH

Network unreachable.

ENFILE

Too many files open in system.

ENOBUFS

No buffer space available.

ENODATA

No message is available on the STREAM head read queue.

ENODEV

No such device.

ENOENT

No such file or directory.

ENOEXEC

Executable file format error.

ENOLCK

No locks available.

ENOLINK

Reserved.

ENOMEM

Not enough space.

ENOMSG

No message of the desired type.

ENOPROTOOPT

Protocol not available.

ENOSPC

No space left on device.

ENOSR

No STREAM resources.

ENOSTR

Not a STREAM.

ENOSYS

Function not supported.

ENOTCONN

The socket is not connected.

ENOTDIR

Not a directory.

ENOTEMPTY

Directory not empty.

ENOTSOCK

Not a socket.

ENOTSUP

Not supported.

ENOTTY

Inappropriate I/O control operation.

ENXIO

No such device or address.

EOPNOTSUPP

Operation not supported on socket.

EOVERFLOW

Value too large to be stored in data type.

EPERM

Operation not permitted.

EPIPE

Broken pipe.

EPROTO

Protocol error.

EPROTONOSUPPORT

Protocol not supported.

EPROTOTYPE

Protocol wrong type for socket.

ERANGE

Result too large.

EROFS

Read-only file system.

ESPIPE

Invalid seek.

ESRCH

No such process.

ESTALE

Reserved.

ETIME

Stream ioctl() timeout.

ETIMEDOUT

Connection timed out.

ETXTBSY

Text file busy.

EWOULDBLOCK

Operation would block (may be the same value as [EAGAIN]).

EXDEV

Cross-device link.

The following sections are informative.

Additional error numbers may be defined on conforming systems; see the System Interfaces volume of IEEE Std 1003.1-2001.

None.

None.

The System Interfaces volume of IEEE Std 1003.1-2001, Section 2.3, Error Numbers

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .