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 errno(2)							    errno(2)




 NAME
      errno - error indicator for function calls

 SYNOPSIS
      #include <&lt&lt&lt;errno.h>&gt&gt&gt;

 DESCRIPTION
      Many functions in the HP-UX operating system indicate an error
      condition by returning an otherwise out-of-range value (usually -1).
      Most of these functions set the symbol errno, that is defined in
      errno.h, to a nonzero code value that more specifically identifies the
      particular error condition that was encountered.

      All errors detected and the corresponding error code values stored in
      errno are documented in the ERRORS section on manual pages for those
      functions that set it.

      The value of errno is zero immediately after a successful call to any
      of the functions described by exec(2) and ptrace(2), but it is never
      set to zero by any other HP-UX function.	Functions for which the use
      of errno is not described may nevertheless change its value to a
      nonzero value.

      Since errno is not cleared on successful function calls, its value
      should be checked or used only when an error has been indicated and
      when the function's ERRORS section documents the error codes.

      Applications should not attempt to take the address of errno.  The
      practice of defining errno as extern int errno is obsolescent.

      The following is a complete list of the error codes.  The numeric
      values can be found in <errno.h> but they should not be used in an
      application program because they can vary from system to system.

      [E2BIG]	     Arg list too long.	 An argument and or environment list
		     longer than maximum supported size is presented to a
		     member of the exec() family.  Other possibilities
		     include: message size or number of semaphores exceeds
		     system limit (msgop, semop), or too many privileged
		     groups have been set up (setprivgrp).

      [EACCES]	     Permission denied.	 An attempt was made to access a
		     file or IPC object in a way forbidden by the protection
		     system.

      [EADDRINUSE]   Address already in use.  Only one usage of each address
		     is normally permitted.

      [EADDRNOTAVAIL]
		     Cannot assign requested address.  Normally results from
		     an attempt to create a socket with an address not on



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 errno(2)							    errno(2)




		     this machine.

      [EAFNOSUPPORT] Address family not supported by protocol family.  An
		     address incompatible with the requested protocol was
		     used.  For example, you should not necessarily expect
		     to be able to use PUP Internet addresses with ARPA
		     Internet protocols.

      [EAGAIN]	     Resource temporarily unavailable.	This is likely a
		     temporary condition, and later calls to the same
		     routine may complete normally.

      [EALREADY]     Operation already in progress.  An operation was
		     attempted on a nonblocking object which already had an
		     operation in progress.

      [EBADF]	     Bad file number.  Either a file descriptor refers to no
		     open file, a read (respectively write) request is made
		     to a file which is open only for writing (respectively
		     reading), or the file descriptor is not in the legal
		     range of file descriptors.

      [EBUSY]	     Device or resource busy.  An attempt to mount a device
		     that was already mounted or an attempt was made to
		     dismount a device on which there is an active file
		     (open file, current directory, mounted-on file, active
		     text segment).  It will also occur if an attempt is
		     made to enable accounting when it is already enabled.
		     The device or resource is currently unavailable, such
		     as when a nonsharable device file is in use.

      [ECHILD]	     No child processes.  A wait() was executed by a process
		     that had no existing or unwaited-for child processes.

      [ECONNABORTED] Software caused connection abort.	A connection abort
		     was caused internal to your host machine.

      [ECONNREFUSED] Connection refused.  No connection could be made
		     because the target machine actively refused it.  This
		     usually results from trying to connect to a service
		     that is inactive on the foreign host.

      [ECONNRESET]   Connection reset by peer.	A connection was forcibly
		     closed by a peer.	This normally results from the peer
		     executing a shutdown() call (see shutdown(2)).

      [EDEADLK]	     Resource deadlock would occur.  A process which has
		     locked a system resource would have been put to sleep
		     while attempting to access another process' locked
		     resource.




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 errno(2)							    errno(2)




      [EDESTADDRREQ] Destination address required.  A required address was
		     omitted from an operation on a socket.

      [EDOM]	     Math argument.  The argument of a function in the math
		     package (3M) is out of the domain of the function.

      [EEXIST]	     File exists.  An existing file was mentioned in an
		     inappropriate context; e.g., link().

      [EFAULT]	     Bad address.  The system encountered a hardware fault
		     in attempting to use an argument of a system call; can
		     also result from passing the wrong number of parameters
		     to a system call.	The reliable detection of this error
		     is implementation dependent.

      [EFBIG]	     File too large.  The size of a file exceeded the
		     maximum file size (for the file system) or ULIMIT was
		     exceeded (see ulimit(2)), or a bad semaphore number in
		     a semop() call (see semop(2)).

      [EHOSTDOWN]    Host is down.  A socket operation encountered a dead
		     host.  Networking activity on the local host has not
		     been initiated.

      [EHOSTUNREACH] No route to host.	A socket operation was attempted to
		     an unreachable host.

      [EIDRM]	     Identifier Removed.  This error is returned to
		     processes that resume execution due to the removal of
		     an identifier from the file system's name space (see
		     msgctl(2), semctl(2), and shmctl(2)).

      [EILSEQ]	     Illegal byte sequence.  A wide character code has been
		     detected that does not correspond to a valid character,
		     or a byte sequence does not form a valid wide character
		     code.

      [EINPROGRESS]  Operation now in progress.	 An operation that takes a
		     long time to complete was attempted on a nonblocking
		     object (see ioctl(2) and fcntl(2)).

      [EINTR]	     Interrupted system call.  An asynchronous signal (such
		     as interrupt or quit), which the user has elected to
		     catch, occurred during a system call.  If execution is
		     resumed after processing the signal, it will appear as
		     if the interrupted system call returned this error
		     condition unless the system call is restarted (see
		     sigvector(2)).

      [EINVAL]	     Invalid argument.	Some invalid argument (such as
		     unmounting a device that is not currently mounted,



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 errno(2)							    errno(2)




		     mentioning an undefined signal in signal() or kill(),
		     or reading or writing a file for which lseek() has
		     generated a negative pointer).  Also set by the math
		     functions described in the (3M) entries of this manual.

      [EIO]	     I/O error - some physical I/O error.  This error may in
		     some cases occur on a call following the one to which
		     it actually applies.

      [EISCONN]	     Socket is already connected.  A connect() request was
		     made on an already connected socket, or, a sendto() or
		     sendmsg() request on a connected socket specified a
		     destination other than the connected party.

      [EISDIR]	     Is a directory.  An attempt to open a directory for
		     writing.

      [ELOOP]	     Too many levels of symbolic links.	 A path name search
		     involved more than MAXSYMLINKS symbolic links.
		     MAXSYMLINKS is defined in <sys/param.h>.

      [EMFILE]	     Too many open files.  No process may have more than a
		     system-defined number of file descriptors open at a
		     time.

      [EMLINK]	     Too many links.  An attempt to make more than the
		     maximum number of links to a file.

      [EMSGSIZE]     Message too long.	The socket requires that the message
		     be sent atomically, and the size of the message to be
		     sent made this impossible.

      [ENAMETOOLONG] File name too long.  A path specified exceeds the
		     maximum path length for the system.  The maximum path
		     length is specified by PATH_MAX and is defined in
		     <limits.h>.  PATH_MAX is guaranteed to be at least 1023
		     bytes.  This error is also generated if the length of a
		     path name component exceeds NAME_MAX and the
		     _POSIX_NO_TRUNC option is in effect for the specified
		     path.  Currently, _POSIX_NO_TRUNC is in effect only for
		     HFS file systems configured to allow path name
		     components up to 255 bytes long (see convertfs(1M)) and
		     therefore only path names referring to such file
		     systems can generate the error for this case.  The
		     values of NAME_MAX, PATH_MAX, and _POSIX_NO_TRUNC for a
		     particular path name can be queried by using the
		     pathconf() system call (see pathconf(2)).

      [ENETDOWN]     Network is down.  A socket operation encountered a dead
		     network.




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 errno(2)							    errno(2)




      [ENETRESET]    Network dropped connection on reset.  The host you were
		     connected to crashed and rebooted.

      [ENETUNREACH]  Network is unreachable.  A socket operation was
		     attempted to an unreachable network.

      [ENFILE]	     File table overflow.  The system's table of open files
		     is full, and temporarily no more open()s can be
		     accepted.

      [ENOBUFS]	     No buffer space available.	 An operation on a socket
		     was not performed because the system lacked sufficient
		     buffer space.

      [ENODEV]	     No such device.  An attempt was made to apply an
		     inappropriate system call to a device (such as read a
		     write-only device).

      [ENOENT]	     No such file or directory.	 This error occurs when a
		     file name is specified and the file should exist but
		     does not, or when one of the directories in a path name
		     does not exist.  It also occurs with msgget(),
		     semget(), and shmget() when key does not refer to any
		     object and the IPC_CREAT flag is not set.

      [ENOEXEC]	     Exec format error.	 A request is made to execute a file
		     which, although it has the appropriate permissions,
		     does not start with a valid magic number (see
		     a.out(4)), or the file is too small to have a valid
		     executable file header.

      [ENOLCK]	     System lock table is full.	 Too many files have file
		     locks on them, or there are too many record locks on
		     files, or there are too many instances of a reading or
		     writing process sleeping until an enforcement mode lock
		     clears.  This error may also indicate system problems
		     in handling a lock request on a remote NFS file.  This
		     error is also currently returned for all attempts to
		     perform locking operations on a remote NFS file that
		     has its locking enforcement mode bit set, since the
		     stateless nature of NFS prevents maintaining the
		     necessary lock information.

      [ENOLINK]	     No connection. The link with the device has been
		     severed or disconnected.

      [ENOMEM]	     Not enough space.	During a system call such as exec(),
		     brk(), fork(), or sbrk(), a program asks for more space
		     than the system is able to supply.	 This may not be a
		     temporary condition; the maximum space size is a system
		     parameter.	 The error can also occur if there is not



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 errno(2)							    errno(2)




		     enough swap space during a fork().

      [ENOMSG]	     No message of desired type.  An attempt was made to
		     receive a message of a type that does not exist on the
		     specified message queue; see msgop(2).

      [ENOPROTOOPT]  Protocol not available.  A bad option was specified in
		     a getsockopt() or setsockopt() call (see
		     getsockopt(2)).

      [ENOSPC]	     No space left on device.  During a write() to an
		     ordinary file, there is no free space left on the
		     device; or no space in system table during msgget(),
		     semget(), or semop() while SEM_UNDO flag is set.

      [ENOSYM]	     Symbol does not exist in executable.  The dynamic
		     loader was unable to resolve a symbolic reference in a
		     shared library during a call to one of the dynamic
		     loader interface routines (see shl_load(3X).  The
		     program may be in an inconsistent state and should be
		     terminated immediately.

      [ENOSYS]	     Function is not available.	 The requested function or
		     operation is not implemented or not configured in the
		     system.

      [ENOTBLK]	     Block device required.  A nonblock file was mentioned
		     where a block device was required, such as in mount().

      [ENOTCONN]     Socket is not connected.  A request to send or receive
		     data was disallowed because the socket was not
		     connected.

      [ENOTDIR]	     Not a directory.  A nondirectory was specified where a
		     directory is required, such as in a path prefix or as
		     an argument to chdir().

      [ENOTEMPTY]    Directory not empty.  An attempt was made to remove a
		     nonempty directory.

      [ENOTSOCK]     Socket operation on nonsocket.  An operation was
		     attempted on something that is not a socket.

      [ENOTTY]	     Not a typewriter.	The (ioctl()) command is
		     inappropriate to the selected device type.

      [ENXIO]	     No such device or address. I/O on a special file refers
		     to a subdevice that does not exist, or is beyond the
		     limits of the device.  It can also occur when, for
		     example, a tape drive is not on line or no disk pack is
		     loaded on a drive.



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 errno(2)							    errno(2)




      [EOPNOTSUPP]   Operation not supported.  The requested operation on a
		     socket or NFS file is either invalid or unsupported.
		     For example, this might occur when an attempt to
		     accept() a connection on a datagram socket fails.

      [EPERM]	     Not owner.	 Typically, this error indicates an attempt
		     to modify a file in some way forbidden except to its
		     owner or the superuser, such as to change its mode.  It
		     is also returned for attempts by ordinary users to do
		     things for which they need, but lack, a special
		     privilege.

      [EPFNOSUPPORT] Protocol family not supported.  The protocol family has
		     not been configured into the system or no
		     implementation for it exists.  The socket is not
		     connected.

      [EPIPE]	     Broken pipe.  Data has been written to a pipe for which
		     the other (reading) end has been closed.  This most
		     often occurs when the reading process exits before the
		     writing process.  This condition also generates the
		     signal SIGPIPE; the error is returned if the signal is
		     ignored.

      [EPROTONOSUPPORT]
		     Protocol not supported.  The protocol has not been
		     configured into the system or no implementation for it
		     exists.

      [EPROTOTYPE]   Protocol wrong type for socket.  A protocol was
		     specified that does not support the semantics of the
		     socket type requested.  For example, ARPA Internet UDP
		     protocol cannot be used with type SOCK_STREAM.

      [ERANGE]	     Result too large.	The value of a function in the math
		     package (3M) is not representable within machine
		     precision, or a semop() call would cause either a
		     semaphore value or a semaphore adjust value to exceed
		     it system-imposed maximum.

      [EROFS]	     Read-only file system.  An attempt to modify a file or
		     directory was made on a device mounted read-only.

      [ESHUTDOWN]    Cannot send after socket shutdown.	 A request to send
		     data was disallowed because the socket had already been
		     shut down with a previous shutdown() call.

      [ESOCKTNOSUPPORT]
		     Socket type not supported.	 The support for the socket
		     type has not been configured into the system or no
		     implementation for it exists.



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 errno(2)							    errno(2)




      [ESPIPE]	     Illegal seek.  An lseek() was issued to a pipe.

      [ESRCH]	     No such process.  No process can be found corresponding
		     to that specified by pid in kill(), rtprio(), or
		     ptrace(), or the process is not accessible.

      [ETIMEDOUT]    Connection timed out.  A connect() request failed
		     because the connected party did not properly respond
		     after a period of time (timeout period varies,
		     depending on the communication protocol).

      [ETXTBSY]	     Text file busy.  An attempt to execute an executable
		     file which is currently open for writing (or reading).
		     Also, an attempt to open for writing an otherwise
		     writable file which is currently open for execution.

      [EWOULDBLOCK]  Operation would block.  An operation which would cause
		     a process to block was attempted on an object in
		     nonblocking mode (see ioctl(2) and fcntl(2)).

      [EXDEV]	     Cross-device link.	 A link to a file on another device
		     was attempted.

 DEPENDENCIES
      The following NFS errors are also defined:

	   [EREFUSED]	  The same error as ECONNREFUSED.  The external
			  variable errno is defined as ECONNREFUSED for NFS
			  compatibility.

	   [EREMOTE]	  Too many levels of remote in path.  An attempt was
			  made to remotely mount an NFS file system into a
			  path which already has a remotely mounted NFS file
			  system component.

	   [ESTALE]	  Stale NFS file handle.  A client referenced an
			  open file, but the file was previously deleted.

 STANDARDS CONFORMANCE
      errno: AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1, ANSI
      C













 Hewlett-Packard Company	    - 8 -   HP-UX Release 11i: November 2000