errno.h(0P)		   POSIX Programmer's Manual		   errno.h(0P)

PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the corresponding
       Linux manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.

NAME
       errno.h — system error numbers

SYNOPSIS
       #include <errno.h>

DESCRIPTION
       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 POSIX.1‐2017
       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 or definition for
       errno.  The symbol errno shall expand to a modifiable lvalue of type
       int.  It is unspecified whether errno is a macro or an identifier
       declared with external linkage. If a macro definition is suppressed in
       order to access an actual object, or a program defines an identifier
       with the name errno, the behavior is undefined.

       The <errno.h> header shall define the following macros which shall
       expand to integer constant expressions with type int, distinct positive
       values (except as noted below), and which shall be suitable for use in
       #if preprocessing directives:

       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 File descriptor value too large.

       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 Functionality not supported.

       ENOTCONN
	      The socket is not connected.

       ENOTDIR
	      Not a directory or a symbolic link to a directory.

       ENOTEMPTY
	      Directory not empty.

       ENOTRECOVERABLE
	      State not recoverable.

       ENOTSOCK
	      Not a socket.

       ENOTSUP
	      Not supported (may be the same value as [EOPNOTSUPP]).

       ENOTTY Inappropriate I/O control operation.

       ENXIO  No such device or address.

       EOPNOTSUPP
	      Operation not supported on socket (may be the same value as
	      [ENOTSUP]).

       EOVERFLOW
	      Value too large to be stored in data type.

       EOWNERDEAD
	      Previous owner died.

       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.

APPLICATION USAGE
       Additional error numbers may be defined on conforming systems; see the
       System Interfaces volume of POSIX.1‐2017.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       The System Interfaces volume of POSIX.1‐2017, Section 2.3, Error
       Numbers

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group		     2017			   errno.h(0P)