errno.h -- Header File

Error numbers used by errno()
#include <errno.h>

errno.h is  the header  file that defines  and describes the  error numbers
returned  in the  external variable  errno. The  following lists  the error
numbers defined in errno.h:

EPERM: Permission denied
     You lack permission to perform the operation you have requested.

ENOENT: No such file or directory
     A program could not find a required file or directory.

ESRCH: No such process
     You are attempting to communicate with a process that does not exist.

EINTR: Interrupted system call
     A COHERENT system call failed because it received a signal or an alarm
     expired.

EIO: I/O error
     A physical  I/O error occurred  on a device  driver.  This could  be a
     tape error, a CRC error on a disk, or a framing error on a synchronous
     HDLC link.

ENXIO: No such device or address
     You attempted to access a device  that does not exist.  It may be that
     a specified minor device is invalid, or the unit is powered off.  This
     error can also indicate that a block number given to a minor device is
     out of  range.  If you attempt  to open a pipe  in write-only mode, if
     O_NDELAY is set,  and if there are currently no  readers on this pipe,
     open() returns immediately and sets errno to ENXIO.

E2BIG: Argument list too long
     The number of bytes of arguments passed in an exec is too large.

ENOEXEC: exec() format error
     The  file given  to exec  is not a  valid executable  module (probably
     because  it does  not have  the magic number  at the  beginning), even
     though its mode indicates that it is executable.

EBADF: Bad file descriptor
     You passed a file descriptor to  a system call for a file that was not
     open  or  was opened  in  a  manner inappropriate  to  the call.   For
     example, a file descriptor opened only for reading may not be accessed
     for writing.

ECHILD: No child processes
     A process issued a wait() call when it had no outstanding children.

EAGAIN: No more processes
     The system cannot create any  more processes, either because it is out
     of table  space or because the invoking process  has reached its quota
     or processes.

ENOMEM: not enough memory
     The system does not have enough memory available to map a process into
     memory.   This occurs  in response  to  a the  system calls  exec() or
     brk().

EACCES: Permission denied
     You do  not have permission to perform the  requested operation upon a
     given file.

EFAULT: Bad address
     You requested  an address that does not lie  within the address space.
     Normally, this generates signal SIGSYS, which terminates the process.

ENOTBLK: Block device required
     You passed to system calls mount() and umount() the descriptor of file
     that is not a block-special device.

EBUSY: Mount device busy
     You passed to the system call  mount() the file descriptor of a device
     that is already mounted; or you passed to the system call umount() the
     descriptor  of  a  device  that  has  open  files  or  active  working
     directories.

EEXIST: File exists
     An attempt was made to link to a file that already exists.

EXDEV: Cross-device link
     You  attempted to  link  a file  on  one file  system with  a file  on
     another.  This is not permitted.

ENODEV: No such device
     You attempted to manipulate a device that does not exist.

ENOTDIR: Not a directory
     You attempted to perform a directory operation upon a file that is not
     a  directory.   For  example, you  passed  the  file  descriptor of  a
     character-special device to system calls chdir() or chroot().

EISDIR: Is a directory
     You attempted to  perform an inappropriate operation upon a directory.
     For example, you passed the file descriptor of a directory to write().

EINVAL: Invalid argument
     An argument to a system call is out of range.  For example, you passed
     to kill()  or umount()  the file  descriptor of a  device that  is not
     mounted.

ENFILE: File table overflow
     The  COHERENT kernel  uses a  static table to  record which  files are
     open.  This error indicates that this  table is full.  Until a file is
     closed, thus freeing space on this  table, no more files can be opened
     on your system.

EMFILE: Too many open files
     The COHERENT  kernel limits the  number of files that  any one process
     can have  open at any given  time; this error indicates  that you have
     exceeded this number.  The system call sysconf() returns the number of
     files that a process can open (among other items of information).  For
     details, see its entry in the Lexicon.

ENOTTY: Not a teletypewriter (tty)
     You attempted  to perform a terminal-specific  operation upon a device
     which is not a terminal.

ETXTBSY: Text file busy
     The text segment of a shared load module is unwritable.  Therefore, an
     attempt to execute it while it  is being written or an attempt to open
     it for writing while it is being executed will fail.

EFBIG: File too large
     The  block-mapping  algorithm for  a  file  fails above  1,082,201,088
     bytes.  Attempting to write a file larger than this will generate this
     error.

ENOSPC: No space left on device
     You attempt  to write  onto a  device that is  full.  If  the attemped
     write  was onto  a file  system,  either the  file system's  supply of
     blocks was exhausted, or its supply of i-nodes was exhausted.

ESPIPE: Tried to seek on a pipe
     It is illegal to invoke the system call lseek() on a pipe.

EROFS: Read-only file system
     You attempted to write onto a file system mounted read-only.

EMLINK: Too many links
     A  file  can have  no  more  than 32,767  links.   The attempted  link
     operation would exceed this value.

EPIPE: Broken pipe
     You attempted  to invoke the system  call write() on a  pipe for which
     there are  no readers.   This condition  is accompanied by  the signal
     SIGPIPE, so  the error will be  seen only if the  signal is ignored or
     caught.

EDOM: Mathematics library domain error
     An argument  to a mathematical  routine falls outside  that function's
     domain.

ERANGE: Mathematics library result too large
     The result of a mathematical function is too large to be represented.

ENOMSG: No message of desired type
     You invoked msgrcv()  to read a message of a  given type, but none was
     waiting to be read.

EIDRM: Identifier removed

EDEADLK: Deadlock condition
     A process is deadlocked for some reason.

ENOLCK: No record locks available
     The maximum number of record locks has been exceeded.

ENOSTR: Device not a stream
     You attempted to  perform a STREAMS operation on a  file that is not a
     stream.

ENODATA: No data available

ETIME: Timer expired

ENOSR: Out of STREAMS resources

ENOPKG: Package not installed

EPROTO: Protocol error

EBADMSG: Not a data message

ENAMETOOLONG: File name too long

EOVERFLOW: Value too large for defined data type

ENOTUNIQ: Name not unique on network

EBADFD: File descriptor in bad state

EREMCHG: Remote address changed

ELIBACC: Cannot access a needed shared library
     COHERENT does not yet support shared libraries.

ELIBBAD: Accessing a corrupted shared library
     COHERENT does not yet support shared libraries.

ELIBSCN: .lib section in a.out corrupted

ELIBMAX: Maximum number of shared libraries exceeded
     COHERENT does not yet support shared libraries.

ELIBEXEC: Cannot exec() a shared library directly
     COHERENT does not yet support shared libraries.

EILSEQ: Illegal byte sequence

ENOSYS: Operation not applicable

ELOOP: Symbolic links error.
     Number  of  symbolic  links  encountered  during path  name  traversal
     exceeds MAXSYMLINKS. COHERENT does not yet support symbolic links.

EUSERS: Too many users

ENOTSOCK: Socket operation on non-socket

EDESTADDRREQ: Destination address required

EMSGSIZE: Message too long

EPROTOTYPE: Protocol wrong type for socket

ENOPROTOOPT: Protocol not available

EPROTONOSUPPORT: Protocol not supported

ESOCKTNOSUPPORT: Socket type not supported

EOPNOTSUPP: Operation not supported on transport endpoint

EPFNOSUPPORT: Protocol family not supported

EAFNOSUPPORT: Address family not supported by protocol family

EADDRINUSE: Address already in use

EADDRNOTAVAIL: Cannot assign requested address

ENETDOWN: Network is down

ENETUNREACH: Network is unreachable

ENETRESET: Network dropped connection because of reset

ECONNABORTED: Software-caused connection abort

ECONNRESET: Connection reset by peer

ENOBUFS: No buffer space available

EISCONN: Transport endpoint is already connected

ENOTCONN: Transport endpoint is not connected

ESHUTDOWN: Cannot send after transport endpoint shutdown

ETIMEDOUT: Connection timed out

ECONNREFUSED: Connection refused

EHOSTDOWN: Host is down

EHOSTUNREACH: No route to host

EALREADY: Operation already in progress

EINPROGRESS: Operation now in progress

ESTALE: Stale NFS file handle
     COHERENT does not yet support nonproprietary file systems.

See Also

errno,
header files,
perror(),
signal()
ANSI Standard, §7.1.3
POSIX Standard, §2.4

© 2012 by Stephen A. Ness