Standard library header <cerrno>

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Standard Library header files

Language Support
<cstddef> <limits> <climits> <cfloat> <cstdint> <new> <typeinfo> <exception> <ciso646>	<initializer_list> <csignal> <csetjmp> <cstdalign> <cstdarg> <cstdbool> <cstdlib> <ctime>
Diagnostics
<stdexcept> <cassert>	<cerrno> <system_error>
General utilities
<utility> <tuple> <bitset> <memory> <cstdlib> <cstring> <functional>	<type_traits> <ratio> <chrono> <ctime> <scoped_allocator> <typeindex>
Strings
<string> <cctype> <cwctype> <cstring>	<cwchar> <cstdlib> <cuchar>
Localization
<locale> <codecvt> <clocale>

Containers
<array> <deque> <forward_list> <list> <vector>	<map> <set> <unordered_map> <unordered_set> <queue> <stack>
Iterators
<iterator>
Algorithms
<algorithm>	<cstdlib>
Numerics
<cfenv> <complex> <random> <valarray>	<numeric> <cmath> <ctgmath> <cstdlib>
Input/Output
<iosfwd> <iostream> <ios> <streambuf> <istream> <ostream>	<iomanip> <sstream> <fstream> <cstdio> <cinttypes>
Regular expressions
<regex>
Thread support
<thread> <mutex> <atomic>	<shared_mutex> <condition_variable> <future>

 

This header was originally in the C standard library as <errno.h>.

This header is part of the error handling library.

Macros

errno	macro which expands to POSIX-compatible thread-local error number variable (macro variable)
E2BIG (C++11)	Argument list too long (macro constant)
EACCES (C++11)	Permission denied (macro constant)
EADDRINUSE (C++11)	Address in use (macro constant)
EADDRNOTAVAIL (C++11)	Address not available (macro constant)
EAFNOSUPPORT (C++11)	Address family not supported (macro constant)
EAGAIN (C++11)	Resource unavailable, try again (macro constant)
EALREADY (C++11)	Connection already in progress (macro constant)
EBADF (C++11)	Bad file descriptor (macro constant)
EBADMSG (C++11)	Bad message (macro constant)
EBUSY (C++11)	Device or resource busy (macro constant)
ECANCELED (C++11)	Operation canceled (macro constant)
ECHILD (C++11)	No child processes (macro constant)
ECONNABORTED (C++11)	Connection aborted (macro constant)
ECONNREFUSED (C++11)	Connection refused (macro constant)
ECONNRESET (C++11)	Connection reset (macro constant)
EDEADLK (C++11)	Resource deadlock would occur (macro constant)
EDESTADDRREQ (C++11)	Destination address required (macro constant)
EDOM	Mathematics argument out of domain of function (macro constant)
EEXIST (C++11)	File exists (macro constant)
EFAULT (C++11)	Bad address (macro constant)
EFBIG (C++11)	File too large (macro constant)
EHOSTUNREACH (C++11)	Host is unreachable (macro constant)
EIDRM (C++11)	Identifier removed (macro constant)
EILSEQ (C++11)	Illegal byte sequence (macro constant)
EINPROGRESS (C++11)	Operation in progress (macro constant)
EINTR (C++11)	Interrupted function (macro constant)
EINVAL (C++11)	Invalid argument (macro constant)
EIO (C++11)	I/O error (macro constant)
EISCONN (C++11)	Socket is connected (macro constant)
EISDIR (C++11)	Is a directory (macro constant)
ELOOP (C++11)	Too many levels of symbolic links (macro constant)
EMFILE (C++11)	File descriptor value too large (macro constant)
EMLINK (C++11)	Too many links (macro constant)
EMSGSIZE (C++11)	Message too large (macro constant)
ENAMETOOLONG (C++11)	Filename too long (macro constant)
ENETDOWN (C++11)	Network is down (macro constant)
ENETRESET (C++11)	Connection aborted by network (macro constant)
ENETUNREACH (C++11)	Network unreachable (macro constant)
ENFILE (C++11)	Too many files open in system (macro constant)
ENOBUFS (C++11)	No buffer space available (macro constant)
ENODATA (C++11)	No message is available on the STREAM head read queue (macro constant)
ENODEV (C++11)	No such device (macro constant)
ENOENT (C++11)	No such file or directory (macro constant)
ENOEXEC (C++11)	Executable file format error (macro constant)
ENOLCK (C++11)	No locks available (macro constant)
ENOLINK (C++11)	Link has been severed (macro constant)
ENOMEM (C++11)	Not enough space (macro constant)
ENOMSG (C++11)	No message of the desired type (macro constant)
ENOPROTOOPT (C++11)	Protocol not available (macro constant)
ENOSPC (C++11)	No space left on device (macro constant)
ENOSR (C++11)	No STREAM resources (macro constant)
ENOSTR (C++11)	Not a STREAM (macro constant)
ENOSYS (C++11)	Function not supported (macro constant)
ENOTCONN (C++11)	The socket is not connected (macro constant)
ENOTDIR (C++11)	Not a directory (macro constant)
ENOTEMPTY (C++11)	Directory not empty (macro constant)
ENOTRECOVERABLE (C++11)	State not recoverable (macro constant)
ENOTSOCK (C++11)	Not a socket (macro constant)
ENOTSUP (C++11)	Not supported (macro constant)
ENOTTY (C++11)	Inappropriate I/O control operation (macro constant)
ENXIO (C++11)	No such device or address (macro constant)
EOPNOTSUPP (C++11)	Operation not supported on socket (macro constant)
EOVERFLOW (C++11)	Value too large to be stored in data type (macro constant)
EOWNERDEAD (C++11)	Previous owner died (macro constant)
EPERM (C++11)	Operation not permitted (macro constant)
EPIPE (C++11)	Broken pipe (macro constant)
EPROTO (C++11)	Protocol error (macro constant)
EPROTONOSUPPORT (C++11)	Protocol not supported (macro constant)
EPROTOTYPE (C++11)	Protocol wrong type for socket (macro constant)
ERANGE	Result too large (macro constant)
EROFS (C++11)	Read-only file system (macro constant)
ESPIPE (C++11)	Invalid seek (macro constant)
ESRCH (C++11)	No such process (macro constant)
ETIME (C++11)	Stream ioctl() timeout (macro constant)
ETIMEDOUT (C++11)	Connection timed out (macro constant)
ETXTBSY (C++11)	Text file busy (macro constant)
EWOULDBLOCK (C++11)	Operation would block (macro constant)
EXDEV (C++11)	Cross-device link (macro constant)

See Also

• Description for the error number values