ERRNO Values

This appendix lists all ERRNO values issued by the C run-time routines. The external int variable errno contains the number of the most recent error or warning condition detected by the run-time library. To use this value, include the header file <errno.h>.

If no error or warning condition is detected, the value of errno is 0. After program execution starts, errno is never reset to 0 by the library. Programs that use errno for information about unusual conditions must set it to 0 before calling a library routine that may detect such a condition.

The <errno.h> file contains declarations of the errno variable and definitions of symbolic names for the values that can be assigned. These names rather than numeric values should be used for errno.

The ERRNO values currently defined are:

E2BIG: argument list for exec function too large
EACCES: inaccessible socket or permission denied
EADDRINUSE: socket address already in use
EADDRNOTAVAIL: socket address not available
EAFNOSUPPORT: unsupported socket addressing family
EAGAIN: resource temporarily unavailable
EALREADY: previous connection not yet completed
EARG: undefined function argument value
EBADF: file or socket not open or suitable (synonym for ENOTOPEN)
EBUSY: resource busy (synonym for EINUSE)
ECHILD: child process not found
ECONNABORTED: connection aborted by local network software
ECONNREFUSED: destination host refused socket connection
ECONNRESET: connection reset by peer
ECONV: data conversion failure
ECORRUPT: file is in a corrupt or unreadable state
EDEADLK: resource deadlock avoided
EDESTADRREQ: socket operation requires destination address
EDEVICE: physical device error
EDOM: math function domain error
EDUPKEY: attempt to add record with duplicate key
EEXIST: file already exists
EFATTR: file attribute conflict
EFAULT: invalid argument address
EFBIG: file too large
EFFORM: file format error
EFORBID: function execution prevented by run-time options
EHOSTDOWN: destination host is down
EHOSTUNREACH: destination host is unreachable
EILSEQ: error in multi-byte character sequence (reserved for future use)
EINPROGRESS: socket connection in progress
EINTR: function failed due to interruption by signal
EINUSE: file to be opened was already in use
EINVAL: invalid argument (synonym for EARG)
EIO: physical I/O error (synonym for EDEVICE)
EISCONN: socket is already connected
EISDIR: output file is a directory
ELIBERR: run-time system internal error
ELIMIT: internal limit exceeded
ELOOP: too many symbolic links in pathname (1003.1a)
EMAIN: synonymous error (synonym for ESYN)
EMFILE: too many open files (synonym for ELIMIT)
EMLINK: system limit on links exceeded
EMSGSIZE: message too large for datagram socket
EMVSCATLG: OpenEdition catalog OBTAIN error
EMVSCVAF: OpenEdition CVAF error
EMVSDYNALC: OpenEdition dynamic allocation error
EMVSERR: OpenEdition system error
EMVSEXPIRE: expired password
EMVSINITIAL: error in establishing OpenEdition process
EMVSNOTUP: OpenEdition kernel is not active
EMVSPARM: erroneous parameters for OpenEdition service (synonym for ELIBERR)
EMVSPASSWORD: incorrect password
EMVSPFSFILE: OpenEdition physical file error
EMVSPFSPERM: OpenEdition HFS system error
EMVSSSAF2ERR: OpenEdition security error
EMVSSAFEXTRERR: OpenEdition security extract error
ENAMETOOLONG: filename too long
ENETDOWN: local host's network down or inaccessible
ENETRESET: remote host dropped network communications
ENETUNREACH: destination network is unreachable
ENFILE: too many open HFS files in system
ENFOUND: file not found
ENOBUFS: insufficient buffers in network software
ENODEV: inappropriate use of device
ENOENT: file or directory not found (synonym for ENFOUND)
ENOEXEC: attempt to execute non-executable file
ENOLCK: no HFS record locks were available
ENOMEM: insufficient memory
ENOPROTOOPT: option not supported for protocol type
ENOSPC: no space in file
ENOSYS: function not implemented by system
ENOTCONN: socket is not connected
ENOTDIR: pathname component not a directory
ENOTEMPTY: directory not empty
ENOTOPEN: synonym for EBADF
ENOTSOCK: file descriptor not associated with a socket
ENOTTY: file is not a terminal
ENXIO: non-existent or inappropriate device
EOPNOTSUPP: operation not supported on socket
EPERM: operation not permitted
EPFNOSUPPORT: unsupported socket protocol family
EPIPE: write to pipe with no reader
EPREV: previous error not cleared
EPROTONOSUPPORT: unsupported socket protocol
EPROTOTYPE: protocol inconsistent with socket type
ERANGE: math function range error
EROFS: file system mounted read only
ESHUTDOWN: connection has been shut down
ESOCKTNOSUPPORT: socket type not allowed
ESPIPE: seek to unseekable file (synonym for EUNSUPP)
ESRCH: process not found
ESYS: operating system interface failure
ETIMEDOUT: socket connection attempt timed out
EUNSUPP: unsupported I/O operation
EUSAGE: incorrect function usage.
EWOULDBLOCK: socket operation would block
EXDEV: link from one file system to another