errno.2 (2010 09)

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errno(2) errno(2)

NAME

errno - error indicator for function calls

SYNOPSIS

#include <errno.h>

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.

In most cases, the manpages for functions that set

errno list those errno values and error descriptions

in the ERRORS section of the manpages. However, failures in underlying functions, subsystems, and

applications may return

errno values that are not documented in the calling functions’ manpages.

The value of

errno is zero immediately after a successful call to any of the functions described by

exec(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 forbid-

den 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 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 una-

vailable, 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.

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (6 pages)

PAGE 1
errno(2) errno(2) NAME errno - error indicator for function calls SYNOPSIS #include 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.
PAGE 2
errno(2) errno(2) [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.
PAGE 3
errno(2) errno(2) [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 . PATH_MAX is guaranteed to be at least 1023 bytes.
PAGE 4
errno(2) errno(2) [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.
PAGE 5
errno(2) [ESPIPE] [ESRCH] errno(2) Illegal seek. An lseek() was issued to a pipe. No such process. No process can be found corresponding to that specified by pid in kill() or rtprio(), 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.
PAGE 6
(Notes) A (Notes) eA 6 Hewlett-Packard Company −1− HP-UX 11i Version 3: September 2010