@node Error Reporting, Memory, Introduction, Top

@chapter Error Reporting

@c %MENU% How library functions report errors

@cindex error reporting

@cindex reporting errors

@cindex error codes

@cindex status codes

Many functions in @theglibc{} detect and report error conditions,

and sometimes your programs need to check for these error conditions.

For example, when you open an input file, you should verify that the

file was actually opened correctly, and print an error message or take

other appropriate action if the call to the library function failed.

This chapter describes how the error reporting facility works.  Your

program should include the header file @file{errno.h} to use this

facility.

@pindex errno.h

@menu

* Checking for Errors::         How errors are reported by library functions.

* Error Codes::                 Error code macros; all of these expand

                                 into integer constant values.

* Error Messages::              Mapping error codes onto error messages.

@end menu

@node Checking for Errors, Error Codes,  , Error Reporting

@section Checking for Errors

Most library functions return a special value to indicate that they have

failed.  The special value is typically @code{-1}, a null pointer, or a

constant such as @code{EOF} that is defined for that purpose.  But this

return value tells you only that an error has occurred.  To find out

what kind of error it was, you need to look at the error code stored in the

variable @code{errno}.  This variable is declared in the header file

@file{errno.h}.

@pindex errno.h

@deftypevr {Variable} {volatile int} errno

@standards{ISO, errno.h}

The variable @code{errno} contains the system error number.  You can

change the value of @code{errno}.

Since @code{errno} is declared @code{volatile}, it might be changed

asynchronously by a signal handler; see @ref{Defining Handlers}.

However, a properly written signal handler saves and restores the value

of @code{errno}, so you generally do not need to worry about this

possibility except when writing signal handlers.

The initial value of @code{errno} at program startup is zero.  In many

cases, when a library function encounters an error, it will set

@code{errno} to a non-zero value to indicate what specific error

condition occurred.  The documentation for each function lists the

error conditions that are possible for that function.  Not all library

functions use this mechanism; some return an error code directly,

instead.

@strong{Warning:} Many library functions may set @code{errno} to some

meaningless non-zero value even if they did not encounter any errors,

and even if they return error codes directly.  Therefore, it is

usually incorrect to check @emph{whether} an error occurred by

inspecting the value of @code{errno}.  The proper way to check for

error is documented for each function.

@strong{Portability Note:} @w{ISO C} specifies @code{errno} as a

``modifiable lvalue'' rather than as a variable, permitting it to be

implemented as a macro.  For example, its expansion might involve a

function call, like @w{@code{*__errno_location ()}}.  In fact, that is

what it is

on @gnulinuxhurdsystems{}.  @Theglibc{}, on each system, does

whatever is right for the particular system.

There are a few library functions, like @code{sqrt} and @code{atan},

that return a perfectly legitimate value in case of an error, but also

set @code{errno}.  For these functions, if you want to check to see

whether an error occurred, the recommended method is to set @code{errno}

to zero before calling the function, and then check its value afterward.

@end deftypevr

@pindex errno.h

All the error codes have symbolic names; they are macros defined in

@file{errno.h}.  The names start with @samp{E} and an upper-case

letter or digit; you should consider names of this form to be

reserved names.  @xref{Reserved Names}.

The error code values are all positive integers and are all distinct,

with one exception: @code{EWOULDBLOCK} and @code{EAGAIN} are the same.

Since the values are distinct, you can use them as labels in a

@code{switch} statement; just don't use both @code{EWOULDBLOCK} and

@code{EAGAIN}.  Your program should not make any other assumptions about

the specific values of these symbolic constants.

The value of @code{errno} doesn't necessarily have to correspond to any

of these macros, since some library functions might return other error

codes of their own for other situations.  The only values that are

guaranteed to be meaningful for a particular library function are the

ones that this manual lists for that function.

Except on @gnuhurdsystems{}, almost any system call can return @code{EFAULT} if

it is given an invalid pointer as an argument.  Since this could only

happen as a result of a bug in your program, and since it will not

happen on @gnuhurdsystems{}, we have saved space by not mentioning

@code{EFAULT} in the descriptions of individual functions.

In some Unix systems, many system calls can also return @code{EFAULT} if

given as an argument a pointer into the stack, and the kernel for some

obscure reason fails in its attempt to extend the stack.  If this ever

happens, you should probably try using statically or dynamically

allocated memory instead of stack memory on that system.

@node Error Codes, Error Messages, Checking for Errors, Error Reporting

@section Error Codes

@pindex errno.h

The error code macros are defined in the header file @file{errno.h}.

All of them expand into integer constant values.  Some of these error

codes can't occur on @gnusystems{}, but they can occur using @theglibc{}

on other systems.

@deftypevr Macro int EPERM

@standards{POSIX.1, errno.h}

@errno{EPERM, 1, Operation not permitted}

Only the owner of the file (or other resource)

or processes with special privileges can perform the operation.

@end deftypevr

@deftypevr Macro int ENOENT

@standards{POSIX.1, errno.h}

@errno{ENOENT, 2, No such file or directory}

This is a ``file doesn't exist'' error

for ordinary files that are referenced in contexts where they are

expected to already exist.

@end deftypevr

@deftypevr Macro int ESRCH

@standards{POSIX.1, errno.h}

@errno{ESRCH, 3, No such process}

No process matches the specified process ID.

@end deftypevr

@deftypevr Macro int EINTR

@standards{POSIX.1, errno.h}

@errno{EINTR, 4, Interrupted system call}

An asynchronous signal occurred and prevented

completion of the call.  When this happens, you should try the call

again.

You can choose to have functions resume after a signal that is handled,

rather than failing with @code{EINTR}; see @ref{Interrupted

Primitives}.

@end deftypevr

@deftypevr Macro int EIO

@standards{POSIX.1, errno.h}

@errno{EIO, 5, Input/output error}

Usually used for physical read or write errors.

@end deftypevr

@deftypevr Macro int ENXIO

@standards{POSIX.1, errno.h}

@errno{ENXIO, 6, No such device or address}

The system tried to use the device

represented by a file you specified, and it couldn't find the device.

This can mean that the device file was installed incorrectly, or that

the physical device is missing or not correctly attached to the

computer.

@end deftypevr

@deftypevr Macro int E2BIG

@standards{POSIX.1, errno.h}

@errno{E2BIG, 7, Argument list too long}

Used when the arguments passed to a new program

being executed with one of the @code{exec} functions (@pxref{Executing a

File}) occupy too much memory space.  This condition never arises on

@gnuhurdsystems{}.

@end deftypevr

@deftypevr Macro int ENOEXEC

@standards{POSIX.1, errno.h}

@errno{ENOEXEC, 8, Exec format error}

Invalid executable file format.  This condition is detected by the

@code{exec} functions; see @ref{Executing a File}.

@end deftypevr

@deftypevr Macro int EBADF

@standards{POSIX.1, errno.h}

@errno{EBADF, 9, Bad file descriptor}

For example, I/O on a descriptor that has been

closed or reading from a descriptor open only for writing (or vice

versa).

@end deftypevr

@deftypevr Macro int ECHILD

@standards{POSIX.1, errno.h}

@errno{ECHILD, 10, No child processes}

This error happens on operations that are

supposed to manipulate child processes, when there aren't any processes

to manipulate.

@end deftypevr

@deftypevr Macro int EDEADLK

@standards{POSIX.1, errno.h}

@errno{EDEADLK, 11, Resource deadlock avoided}

Allocating a system resource would have resulted in a

deadlock situation.  The system does not guarantee that it will notice

all such situations.  This error means you got lucky and the system

noticed; it might just hang.  @xref{File Locks}, for an example.

@end deftypevr

@deftypevr Macro int ENOMEM

@standards{POSIX.1, errno.h}

@errno{ENOMEM, 12, Cannot allocate memory}

The system cannot allocate more virtual memory

because its capacity is full.

@end deftypevr

@deftypevr Macro int EACCES

@standards{POSIX.1, errno.h}

@errno{EACCES, 13, Permission denied}

The file permissions do not allow the attempted operation.

@end deftypevr

@deftypevr Macro int EFAULT

@standards{POSIX.1, errno.h}

@errno{EFAULT, 14, Bad address}

An invalid pointer was detected.

On @gnuhurdsystems{}, this error never happens; you get a signal instead.

@end deftypevr

@deftypevr Macro int ENOTBLK

@standards{BSD, errno.h}

@errno{ENOTBLK, 15, Block device required}

A file that isn't a block special file was given in a situation that

requires one.  For example, trying to mount an ordinary file as a file

system in Unix gives this error.

@end deftypevr

@deftypevr Macro int EBUSY

@standards{POSIX.1, errno.h}

@errno{EBUSY, 16, Device or resource busy}

A system resource that can't be shared is already in use.

For example, if you try to delete a file that is the root of a currently

mounted filesystem, you get this error.

@end deftypevr

@deftypevr Macro int EEXIST

@standards{POSIX.1, errno.h}

@errno{EEXIST, 17, File exists}

An existing file was specified in a context where it only

makes sense to specify a new file.

@end deftypevr

@deftypevr Macro int EXDEV

@standards{POSIX.1, errno.h}

@errno{EXDEV, 18, Invalid cross-device link}

An attempt to make an improper link across file systems was detected.

This happens not only when you use @code{link} (@pxref{Hard Links}) but

also when you rename a file with @code{rename} (@pxref{Renaming Files}).

@end deftypevr

@deftypevr Macro int ENODEV

@standards{POSIX.1, errno.h}

@errno{ENODEV, 19, No such device}

The wrong type of device was given to a function that expects a

particular sort of device.

@end deftypevr

@deftypevr Macro int ENOTDIR

@standards{POSIX.1, errno.h}

@errno{ENOTDIR, 20, Not a directory}

A file that isn't a directory was specified when a directory is required.

@end deftypevr

@deftypevr Macro int EISDIR

@standards{POSIX.1, errno.h}

@errno{EISDIR, 21, Is a directory}

You cannot open a directory for writing,

or create or remove hard links to it.

@end deftypevr

@deftypevr Macro int EINVAL

@standards{POSIX.1, errno.h}

@errno{EINVAL, 22, Invalid argument}

This is used to indicate various kinds of problems

with passing the wrong argument to a library function.

@end deftypevr

@deftypevr Macro int EMFILE

@standards{POSIX.1, errno.h}

@errno{EMFILE, 24, Too many open files}

The current process has too many files open and can't open any more.

Duplicate descriptors do count toward this limit.

In BSD and GNU, the number of open files is controlled by a resource

limit that can usually be increased.  If you get this error, you might

want to increase the @code{RLIMIT_NOFILE} limit or make it unlimited;

@pxref{Limits on Resources}.

@end deftypevr

@deftypevr Macro int ENFILE

@standards{POSIX.1, errno.h}

@errno{ENFILE, 23, Too many open files in system}

There are too many distinct file openings in the entire system.  Note

that any number of linked channels count as just one file opening; see

@ref{Linked Channels}.  This error never occurs on @gnuhurdsystems{}.

@end deftypevr

@deftypevr Macro int ENOTTY

@standards{POSIX.1, errno.h}

@errno{ENOTTY, 25, Inappropriate ioctl for device}

Inappropriate I/O control operation, such as trying to set terminal

modes on an ordinary file.

@end deftypevr

@deftypevr Macro int ETXTBSY

@standards{BSD, errno.h}

@errno{ETXTBSY, 26, Text file busy}

An attempt to execute a file that is currently open for writing, or

write to a file that is currently being executed.  Often using a

debugger to run a program is considered having it open for writing and

will cause this error.  (The name stands for ``text file busy''.)  This

is not an error on @gnuhurdsystems{}; the text is copied as necessary.

@end deftypevr

@deftypevr Macro int EFBIG

@standards{POSIX.1, errno.h}

@errno{EFBIG, 27, File too large}

The size of a file would be larger than allowed by the system.

@end deftypevr

@deftypevr Macro int ENOSPC

@standards{POSIX.1, errno.h}

@errno{ENOSPC, 28, No space left on device}

Write operation on a file failed because the

disk is full.

@end deftypevr

@deftypevr Macro int ESPIPE

@standards{POSIX.1, errno.h}

@errno{ESPIPE, 29, Illegal seek}

Invalid seek operation (such as on a pipe).

@end deftypevr

@deftypevr Macro int EROFS

@standards{POSIX.1, errno.h}

@errno{EROFS, 30, Read-only file system}

An attempt was made to modify something on a read-only file system.

@end deftypevr

@deftypevr Macro int EMLINK

@standards{POSIX.1, errno.h}

@errno{EMLINK, 31, Too many links}

The link count of a single file would become too large.

@code{rename} can cause this error if the file being renamed already has

as many links as it can take (@pxref{Renaming Files}).

@end deftypevr

@deftypevr Macro int EPIPE

@standards{POSIX.1, errno.h}

@errno{EPIPE, 32, Broken pipe}

There is no process reading from the other end of a pipe.

Every library function that returns this error code also generates a

@code{SIGPIPE} signal; this signal terminates the program if not handled

or blocked.  Thus, your program will never actually see @code{EPIPE}

unless it has handled or blocked @code{SIGPIPE}.

@end deftypevr

@deftypevr Macro int EDOM

@standards{ISO, errno.h}

@errno{EDOM, 33, Numerical argument out of domain}

Used by mathematical functions when an argument value does

not fall into the domain over which the function is defined.

@end deftypevr

@deftypevr Macro int ERANGE

@standards{ISO, errno.h}

@errno{ERANGE, 34, Numerical result out of range}

Used by mathematical functions when the result value is

not representable because of overflow or underflow.

@end deftypevr

@deftypevr Macro int EAGAIN

@standards{POSIX.1, errno.h}

@errno{EAGAIN, 35, Resource temporarily unavailable}

The call might work if you try again

later.  The macro @code{EWOULDBLOCK} is another name for @code{EAGAIN};

they are always the same in @theglibc{}.

This error can happen in a few different situations:

@itemize @bullet

@item

An operation that would block was attempted on an object that has

non-blocking mode selected.  Trying the same operation again will block

until some external condition makes it possible to read, write, or

connect (whatever the operation).  You can use @code{select} to find out

when the operation will be possible; @pxref{Waiting for I/O}.

@strong{Portability Note:} In many older Unix systems, this condition

was indicated by @code{EWOULDBLOCK}, which was a distinct error code

different from @code{EAGAIN}.  To make your program portable, you should

check for both codes and treat them the same.

@item

A temporary resource shortage made an operation impossible.  @code{fork}

can return this error.  It indicates that the shortage is expected to

pass, so your program can try the call again later and it may succeed.

It is probably a good idea to delay for a few seconds before trying it

again, to allow time for other processes to release scarce resources.

Such shortages are usually fairly serious and affect the whole system,

so usually an interactive program should report the error to the user

and return to its command loop.

@end itemize

@end deftypevr

@deftypevr Macro int EWOULDBLOCK

@standards{BSD, errno.h}

@errno{EWOULDBLOCK, EAGAIN, Operation would block}

In @theglibc{}, this is another name for @code{EAGAIN} (above).

The values are always the same, on every operating system.

C libraries in many older Unix systems have @code{EWOULDBLOCK} as a

separate error code.

@end deftypevr

@deftypevr Macro int EINPROGRESS

@standards{BSD, errno.h}

@errno{EINPROGRESS, 36, Operation now in progress}

An operation that cannot complete immediately was initiated on an object

that has non-blocking mode selected.  Some functions that must always

block (such as @code{connect}; @pxref{Connecting}) never return

@code{EAGAIN}.  Instead, they return @code{EINPROGRESS} to indicate that

the operation has begun and will take some time.  Attempts to manipulate

the object before the call completes return @code{EALREADY}.  You can

use the @code{select} function to find out when the pending operation

has completed; @pxref{Waiting for I/O}.

@end deftypevr

@deftypevr Macro int EALREADY

@standards{BSD, errno.h}

@errno{EALREADY, 37, Operation already in progress}

An operation is already in progress on an object that has non-blocking

mode selected.

@end deftypevr

@deftypevr Macro int ENOTSOCK

@standards{BSD, errno.h}

@errno{ENOTSOCK, 38, Socket operation on non-socket}

A file that isn't a socket was specified when a socket is required.

@end deftypevr

@deftypevr Macro int EMSGSIZE

@standards{BSD, errno.h}

@errno{EMSGSIZE, 40, Message too long}

The size of a message sent on a socket was larger than the supported

maximum size.

@end deftypevr

@deftypevr Macro int EPROTOTYPE

@standards{BSD, errno.h}

@errno{EPROTOTYPE, 41, Protocol wrong type for socket}

The socket type does not support the requested communications protocol.

@end deftypevr

@deftypevr Macro int ENOPROTOOPT

@standards{BSD, errno.h}

@errno{ENOPROTOOPT, 42, Protocol not available}

You specified a socket option that doesn't make sense for the

particular protocol being used by the socket.  @xref{Socket Options}.

@end deftypevr

@deftypevr Macro int EPROTONOSUPPORT

@standards{BSD, errno.h}

@errno{EPROTONOSUPPORT, 43, Protocol not supported}

The socket domain does not support the requested communications protocol

(perhaps because the requested protocol is completely invalid).

@xref{Creating a Socket}.

@end deftypevr

@deftypevr Macro int ESOCKTNOSUPPORT

@standards{BSD, errno.h}

@errno{ESOCKTNOSUPPORT, 44, Socket type not supported}

The socket type is not supported.

@end deftypevr

@deftypevr Macro int EOPNOTSUPP

@standards{BSD, errno.h}

@errno{EOPNOTSUPP, 45, Operation not supported}

The operation you requested is not supported.  Some socket functions

don't make sense for all types of sockets, and others may not be

implemented for all communications protocols.  On @gnuhurdsystems{}, this

error can happen for many calls when the object does not support the

particular operation; it is a generic indication that the server knows

nothing to do for that call.

@end deftypevr

@deftypevr Macro int EPFNOSUPPORT

@standards{BSD, errno.h}

@errno{EPFNOSUPPORT, 46, Protocol family not supported}

The socket communications protocol family you requested is not supported.

@end deftypevr

@deftypevr Macro int EAFNOSUPPORT

@standards{BSD, errno.h}

@errno{EAFNOSUPPORT, 47, Address family not supported by protocol}

The address family specified for a socket is not supported; it is

inconsistent with the protocol being used on the socket.  @xref{Sockets}.

@end deftypevr

@deftypevr Macro int EADDRINUSE

@standards{BSD, errno.h}

@errno{EADDRINUSE, 48, Address already in use}

The requested socket address is already in use.  @xref{Socket Addresses}.

@end deftypevr

@deftypevr Macro int EADDRNOTAVAIL

@standards{BSD, errno.h}

@errno{EADDRNOTAVAIL, 49, Cannot assign requested address}

The requested socket address is not available; for example, you tried

to give a socket a name that doesn't match the local host name.

@xref{Socket Addresses}.

@end deftypevr

@deftypevr Macro int ENETDOWN

@standards{BSD, errno.h}

@errno{ENETDOWN, 50, Network is down}

A socket operation failed because the network was down.

@end deftypevr

@deftypevr Macro int ENETUNREACH

@standards{BSD, errno.h}

@errno{ENETUNREACH, 51, Network is unreachable}

A socket operation failed because the subnet containing the remote host

was unreachable.

@end deftypevr

@deftypevr Macro int ENETRESET

@standards{BSD, errno.h}

@errno{ENETRESET, 52, Network dropped connection on reset}

A network connection was reset because the remote host crashed.

@end deftypevr

@deftypevr Macro int ECONNABORTED

@standards{BSD, errno.h}

@errno{ECONNABORTED, 53, Software caused connection abort}

A network connection was aborted locally.

@end deftypevr

@deftypevr Macro int ECONNRESET

@standards{BSD, errno.h}

@errno{ECONNRESET, 54, Connection reset by peer}

A network connection was closed for reasons outside the control of the

local host, such as by the remote machine rebooting or an unrecoverable

protocol violation.

@end deftypevr

@deftypevr Macro int ENOBUFS

@standards{BSD, errno.h}

@errno{ENOBUFS, 55, No buffer space available}

The kernel's buffers for I/O operations are all in use.  In GNU, this

error is always synonymous with @code{ENOMEM}; you may get one or the

other from network operations.

@end deftypevr

@deftypevr Macro int EISCONN

@standards{BSD, errno.h}

@errno{EISCONN, 56, Transport endpoint is already connected}

You tried to connect a socket that is already connected.

@xref{Connecting}.

@end deftypevr

@deftypevr Macro int ENOTCONN

@standards{BSD, errno.h}

@errno{ENOTCONN, 57, Transport endpoint is not connected}

The socket is not connected to anything.  You get this error when you

try to transmit data over a socket, without first specifying a

destination for the data.  For a connectionless socket (for datagram

protocols, such as UDP), you get @code{EDESTADDRREQ} instead.

@end deftypevr

@deftypevr Macro int EDESTADDRREQ

@standards{BSD, errno.h}

@errno{EDESTADDRREQ, 39, Destination address required}

No default destination address was set for the socket.  You get this

error when you try to transmit data over a connectionless socket,

without first specifying a destination for the data with @code{connect}.

@end deftypevr

@deftypevr Macro int ESHUTDOWN

@standards{BSD, errno.h}

@errno{ESHUTDOWN, 58, Cannot send after transport endpoint shutdown}

The socket has already been shut down.

@end deftypevr

@deftypevr Macro int ETOOMANYREFS

@standards{BSD, errno.h}

@errno{ETOOMANYREFS, 59, Too many references: cannot splice}

@end deftypevr

@deftypevr Macro int ETIMEDOUT

@standards{BSD, errno.h}

@errno{ETIMEDOUT, 60, Connection timed out}

A socket operation with a specified timeout received no response during

the timeout period.

@end deftypevr

@deftypevr Macro int ECONNREFUSED

@standards{BSD, errno.h}

@errno{ECONNREFUSED, 61, Connection refused}

A remote host refused to allow the network connection (typically because

it is not running the requested service).

@end deftypevr

@deftypevr Macro int ELOOP

@standards{BSD, errno.h}

@errno{ELOOP, 62, Too many levels of symbolic links}

Too many levels of symbolic links were encountered in looking up a file name.

This often indicates a cycle of symbolic links.

@end deftypevr

@deftypevr Macro int ENAMETOOLONG

@standards{POSIX.1, errno.h}

@errno{ENAMETOOLONG, 63, File name too long}

Filename too long (longer than @code{PATH_MAX}; @pxref{Limits for

Files}) or host name too long (in @code{gethostname} or

@code{sethostname}; @pxref{Host Identification}).

@end deftypevr

@deftypevr Macro int EHOSTDOWN

@standards{BSD, errno.h}

@errno{EHOSTDOWN, 64, Host is down}

The remote host for a requested network connection is down.

@end deftypevr

@deftypevr Macro int EHOSTUNREACH

@standards{BSD, errno.h}

@errno{EHOSTUNREACH, 65, No route to host}

The remote host for a requested network connection is not reachable.

@end deftypevr

@deftypevr Macro int ENOTEMPTY

@standards{POSIX.1, errno.h}

@errno{ENOTEMPTY, 66, Directory not empty}

Directory not empty, where an empty directory was expected.  Typically,

this error occurs when you are trying to delete a directory.

@end deftypevr

@deftypevr Macro int EPROCLIM

@standards{BSD, errno.h}

@errno{EPROCLIM, 67, Too many processes}

This means that the per-user limit on new process would be exceeded by

an attempted @code{fork}.  @xref{Limits on Resources}, for details on

the @code{RLIMIT_NPROC} limit.

@end deftypevr

@deftypevr Macro int EUSERS

@standards{BSD, errno.h}

@errno{EUSERS, 68, Too many users}

The file quota system is confused because there are too many users.

@c This can probably happen in a GNU system when using NFS.

@end deftypevr

@deftypevr Macro int EDQUOT

@standards{BSD, errno.h}

@errno{EDQUOT, 69, Disk quota exceeded}

The user's disk quota was exceeded.

@end deftypevr

@deftypevr Macro int ESTALE

@standards{BSD, errno.h}

@errno{ESTALE, 70, Stale file handle}

This indicates an internal confusion in the

file system which is due to file system rearrangements on the server host

for NFS file systems or corruption in other file systems.

Repairing this condition usually requires unmounting, possibly repairing

and remounting the file system.

@end deftypevr

@deftypevr Macro int EREMOTE

@standards{BSD, errno.h}

@errno{EREMOTE, 71, Object is remote}

An attempt was made to NFS-mount a remote file system with a file name that

already specifies an NFS-mounted file.

(This is an error on some operating systems, but we expect it to work

properly on @gnuhurdsystems{}, making this error code impossible.)

@end deftypevr

@deftypevr Macro int EBADRPC

@standards{BSD, errno.h}

@errno{EBADRPC, 72, RPC struct is bad}

@end deftypevr

@deftypevr Macro int ERPCMISMATCH

@standards{BSD, errno.h}

@errno{ERPCMISMATCH, 73, RPC version wrong}

@end deftypevr

@deftypevr Macro int EPROGUNAVAIL

@standards{BSD, errno.h}

@errno{EPROGUNAVAIL, 74, RPC program not available}

@end deftypevr

@deftypevr Macro int EPROGMISMATCH

@standards{BSD, errno.h}

@errno{EPROGMISMATCH, 75, RPC program version wrong}

@end deftypevr

@deftypevr Macro int EPROCUNAVAIL

@standards{BSD, errno.h}

@errno{EPROCUNAVAIL, 76, RPC bad procedure for program}

@end deftypevr

@deftypevr Macro int ENOLCK

@standards{POSIX.1, errno.h}

@errno{ENOLCK, 77, No locks available}

This is used by the file locking facilities; see

@ref{File Locks}.  This error is never generated by @gnuhurdsystems{}, but

it can result from an operation to an NFS server running another

operating system.

@end deftypevr

@deftypevr Macro int EFTYPE

@standards{BSD, errno.h}

@errno{EFTYPE, 79, Inappropriate file type or format}

The file was the wrong type for the

operation, or a data file had the wrong format.

On some systems @code{chmod} returns this error if you try to set the

sticky bit on a non-directory file; @pxref{Setting Permissions}.

@end deftypevr

@deftypevr Macro int EAUTH

@standards{BSD, errno.h}

@errno{EAUTH, 80, Authentication error}

@end deftypevr

@deftypevr Macro int ENEEDAUTH

@standards{BSD, errno.h}

@errno{ENEEDAUTH, 81, Need authenticator}

@end deftypevr

@deftypevr Macro int ENOSYS

@standards{POSIX.1, errno.h}

@errno{ENOSYS, 78, Function not implemented}

This indicates that the function called is

not implemented at all, either in the C library itself or in the

operating system.  When you get this error, you can be sure that this

particular function will always fail with @code{ENOSYS} unless you

install a new version of the C library or the operating system.

@end deftypevr

@deftypevr Macro int ENOTSUP

@standards{POSIX.1, errno.h}

@errno{ENOTSUP, 118, Not supported}

A function returns this error when certain parameter

values are valid, but the functionality they request is not available.

This can mean that the function does not implement a particular command

or option value or flag bit at all.  For functions that operate on some

object given in a parameter, such as a file descriptor or a port, it

might instead mean that only @emph{that specific object} (file

descriptor, port, etc.) is unable to support the other parameters given;

different file descriptors might support different ranges of parameter

values.

If the entire function is not available at all in the implementation,

it returns @code{ENOSYS} instead.

@end deftypevr

@deftypevr Macro int EILSEQ

@standards{ISO, errno.h}

@errno{EILSEQ, 106, Invalid or incomplete multibyte or wide character}

While decoding a multibyte character the function came along an invalid

or an incomplete sequence of bytes or the given wide character is invalid.

@end deftypevr

@deftypevr Macro int EBACKGROUND

@standards{GNU, errno.h}

@errno{EBACKGROUND, 100, Inappropriate operation for background process}

On @gnuhurdsystems{}, servers supporting the @code{term} protocol return

this error for certain operations when the caller is not in the

foreground process group of the terminal.  Users do not usually see this

error because functions such as @code{read} and @code{write} translate

it into a @code{SIGTTIN} or @code{SIGTTOU} signal.  @xref{Job Control},

for information on process groups and these signals.

@end deftypevr

@deftypevr Macro int EDIED

@standards{GNU, errno.h}

@errno{EDIED, 101, Translator died}

On @gnuhurdsystems{}, opening a file returns this error when the file is

translated by a program and the translator program dies while starting

up, before it has connected to the file.

@end deftypevr

@deftypevr Macro int ED

@standards{GNU, errno.h}

@errno{ED, 102, ?}

The experienced user will know what is wrong.

@c This error code is a joke.  Its perror text is part of the joke.

@c Don't change it.

@end deftypevr

@deftypevr Macro int EGREGIOUS

@standards{GNU, errno.h}

@errno{EGREGIOUS, 103, You really blew it this time}

You did @strong{what}?

@end deftypevr

@deftypevr Macro int EIEIO

@standards{GNU, errno.h}

@errno{EIEIO, 104, Computer bought the farm}

Go home and have a glass of warm, dairy-fresh milk.

@end deftypevr

@deftypevr Macro int EGRATUITOUS

@standards{GNU, errno.h}

@errno{EGRATUITOUS, 105, Gratuitous error}

This error code has no purpose.

@end deftypevr

@deftypevr Macro int EBADMSG

@standards{XOPEN, errno.h}

@errno{EBADMSG, 107, Bad message}

@end deftypevr

@deftypevr Macro int EIDRM

@standards{XOPEN, errno.h}

@errno{EIDRM, 108, Identifier removed}

@end deftypevr

@deftypevr Macro int EMULTIHOP

@standards{XOPEN, errno.h}

@errno{EMULTIHOP, 109, Multihop attempted}

@end deftypevr

@deftypevr Macro int ENODATA

@standards{XOPEN, errno.h}

@errno{ENODATA, 110, No data available}

@end deftypevr

@deftypevr Macro int ENOLINK

@standards{XOPEN, errno.h}

@errno{ENOLINK, 111, Link has been severed}

@end deftypevr

@deftypevr Macro int ENOMSG

@standards{XOPEN, errno.h}

@errno{ENOMSG, 112, No message of desired type}

@end deftypevr

@deftypevr Macro int ENOSR

@standards{XOPEN, errno.h}

@errno{ENOSR, 113, Out of streams resources}

@end deftypevr

@deftypevr Macro int ENOSTR

@standards{XOPEN, errno.h}

@errno{ENOSTR, 114, Device not a stream}

@end deftypevr

@deftypevr Macro int EOVERFLOW

@standards{XOPEN, errno.h}

@errno{EOVERFLOW, 115, Value too large for defined data type}

@end deftypevr

@deftypevr Macro int EPROTO

@standards{XOPEN, errno.h}

@errno{EPROTO, 116, Protocol error}

@end deftypevr

@deftypevr Macro int ETIME

@standards{XOPEN, errno.h}

@errno{ETIME, 117, Timer expired}

@end deftypevr

@deftypevr Macro int ECANCELED

@standards{POSIX.1, errno.h}

@errno{ECANCELED, 119, Operation canceled}

An asynchronous operation was canceled before it

completed.  @xref{Asynchronous I/O}.  When you call @code{aio_cancel},