Standard library header <cerrno>
From cppreference.com
This header was originally in the C standard library as <errno.h>.
This header is part of the error handling library.
Macros
| 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 |
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) (deprecated in C++23) |
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) (deprecated in C++23) |
No STREAM resources (macro constant) |
| ENOSTR (C++11) (deprecated in C++23) |
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) (deprecated in C++23) |
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) |
Notes
Although the header <cerrno> is based on the C standard library header <errno.h>, the majority of the macros defined by <cerrno> were adopted by C++ from the POSIX standard, rather than the C standard library.
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 288 | C++98 | the macro EILSEQ was not defined in <cerrno>
|
defined |