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Standard library header <cerrno>

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

This header is part of the error handling library.

Contents

[edit] Macros

macro which expands to POSIX-compatible thread-local error number variable
(macro variable)[edit]
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)

[edit] 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.

[edit] Synopsis

#define errno /* see description */
#define E2BIG /* see description */           // freestanding
#define EACCES /* see description */          // freestanding
#define EADDRINUSE /* see description */      // freestanding
#define EADDRNOTAVAIL /* see description */   // freestanding
#define EAFNOSUPPORT /* see description */    // freestanding
#define EAGAIN /* see description */          // freestanding
#define EALREADY /* see description */        // freestanding
#define EBADF /* see description */           // freestanding
#define EBADMSG /* see description */         // freestanding
#define EBUSY /* see description */           // freestanding
#define ECANCELED /* see description */       // freestanding
#define ECHILD /* see description */          // freestanding
#define ECONNABORTED /* see description */    // freestanding
#define ECONNREFUSED /* see description */    // freestanding
#define ECONNRESET /* see description */      // freestanding
#define EDEADLK /* see description */         // freestanding
#define EDESTADDRREQ /* see description */    // freestanding
#define EDOM /* see description */            // freestanding
#define EEXIST /* see description */          // freestanding
#define EFAULT /* see description */          // freestanding
#define EFBIG /* see description */           // freestanding
#define EHOSTUNREACH /* see description */    // freestanding
#define EIDRM /* see description */           // freestanding
#define EILSEQ /* see description */          // freestanding
#define EINPROGRESS /* see description */     // freestanding
#define EINTR /* see description */           // freestanding
#define EINVAL /* see description */          // freestanding
#define EIO /* see description */             // freestanding
#define EISCONN /* see description */         // freestanding
#define EISDIR /* see description */          // freestanding
#define ELOOP /* see description */           // freestanding
#define EMFILE /* see description */          // freestanding
#define EMLINK /* see description */          // freestanding
#define EMSGSIZE /* see description */        // freestanding
#define ENAMETOOLONG /* see description */    // freestanding
#define ENETDOWN /* see description */        // freestanding
#define ENETRESET /* see description */       // freestanding
#define ENETUNREACH /* see description */     // freestanding
#define ENFILE /* see description */          // freestanding
#define ENOBUFS /* see description */         // freestanding
#define ENODEV /* see description */          // freestanding
#define ENOENT /* see description */          // freestanding
#define ENOEXEC /* see description */         // freestanding
#define ENOLCK /* see description */          // freestanding
#define ENOLINK /* see description */         // freestanding
#define ENOMEM /* see description */          // freestanding
#define ENOMSG /* see description */          // freestanding
#define ENOPROTOOPT /* see description */     // freestanding
#define ENOSPC /* see description */          // freestanding
#define ENOSYS /* see description */          // freestanding
#define ENOTCONN /* see description */        // freestanding
#define ENOTDIR /* see description */         // freestanding
#define ENOTEMPTY /* see description */       // freestanding
#define ENOTRECOVERABLE /* see description */ // freestanding
#define ENOTSOCK /* see description */        // freestanding
#define ENOTSUP /* see description */         // freestanding
#define ENOTTY /* see description */          // freestanding
#define ENXIO /* see description */           // freestanding
#define EOPNOTSUPP /* see description */      // freestanding
#define EOVERFLOW /* see description */       // freestanding
#define EOWNERDEAD /* see description */      // freestanding
#define EPERM /* see description */           // freestanding
#define EPIPE /* see description */           // freestanding
#define EPROTO /* see description */          // freestanding
#define EPROTONOSUPPORT /* see description */ // freestanding
#define EPROTOTYPE /* see description */      // freestanding
#define ERANGE /* see description */          // freestanding
#define EROFS /* see description */           // freestanding
#define ESPIPE /* see description */          // freestanding
#define ESRCH /* see description */           // freestanding
#define ETIMEDOUT /* see description */       // freestanding
#define ETXTBSY /* see description */         // freestanding
#define EWOULDBLOCK /* see description */     // freestanding
#define EXDEV /* see description */           // freestanding

[edit] 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

[edit] See also