errno.h(0p)

1errno.h(0P)                POSIX Programmer's Manual               errno.h(0P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
10

NAME

12       errno.h — system error numbers
13

SYNOPSIS

15       #include <errno.h>
16

DESCRIPTION

18       Some of the functionality described on this reference page extends  the
19       ISO C  standard.  Any  conflict between the requirements described here
20       and the ISO C standard is unintentional. This  volume  of  POSIX.1‐2017
21       defers to the ISO C standard.
22
23       The  ISO C  standard  only  requires  the symbols [EDOM], [EILSEQ], and
24       [ERANGE] to be defined.
25
26       The <errno.h> header shall provide  a  declaration  or  definition  for
27       errno.   The  symbol  errno shall expand to a modifiable lvalue of type
28       int.  It is unspecified whether errno  is  a  macro  or  an  identifier
29       declared  with external linkage. If a macro definition is suppressed in
30       order to access an actual object, or a program  defines  an  identifier
31       with the name errno, the behavior is undefined.
32
33       The  <errno.h>  header  shall  define  the following macros which shall
34       expand to integer constant expressions with type int, distinct positive
35       values  (except as noted below), and which shall be suitable for use in
36       #if preprocessing directives:
37
38       E2BIG  Argument list too long.
39
40       EACCES Permission denied.
41
42       EADDRINUSE
43              Address in use.
44
45       EADDRNOTAVAIL
46              Address not available.
47
48       EAFNOSUPPORT
49              Address family not supported.
50
51       EAGAIN Resource unavailable, try  again  (may  be  the  same  value  as
52              [EWOULDBLOCK]).
53
54       EALREADY
55              Connection already in progress.
56
57       EBADF  Bad file descriptor.
58
59       EBADMSG
60              Bad message.
61
62       EBUSY  Device or resource busy.
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64       ECANCELED
65              Operation canceled.
66
67       ECHILD No child processes.
68
69       ECONNABORTED
70              Connection aborted.
71
72       ECONNREFUSED
73              Connection refused.
74
75       ECONNRESET
76              Connection reset.
77
78       EDEADLK
79              Resource deadlock would occur.
80
81       EDESTADDRREQ
82              Destination address required.
83
84       EDOM   Mathematics argument out of domain of function.
85
86       EDQUOT Reserved.
87
88       EEXIST File exists.
89
90       EFAULT Bad address.
91
92       EFBIG  File too large.
93
94       EHOSTUNREACH
95              Host is unreachable.
96
97       EIDRM  Identifier removed.
98
99       EILSEQ Illegal byte sequence.
100
101       EINPROGRESS
102              Operation in progress.
103
104       EINTR  Interrupted function.
105
106       EINVAL Invalid argument.
107
108       EIO    I/O error.
109
110       EISCONN
111              Socket is connected.
112
113       EISDIR Is a directory.
114
115       ELOOP  Too many levels of symbolic links.
116
117       EMFILE File descriptor value too large.
118
119       EMLINK Too many links.
120
121       EMSGSIZE
122              Message too large.
123
124       EMULTIHOP
125              Reserved.
126
127       ENAMETOOLONG
128              Filename too long.
129
130       ENETDOWN
131              Network is down.
132
133       ENETRESET
134              Connection aborted by network.
135
136       ENETUNREACH
137              Network unreachable.
138
139       ENFILE Too many files open in system.
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141       ENOBUFS
142              No buffer space available.
143
144       ENODATA
145              No message is available on the STREAM head read queue.
146
147       ENODEV No such device.
148
149       ENOENT No such file or directory.
150
151       ENOEXEC
152              Executable file format error.
153
154       ENOLCK No locks available.
155
156       ENOLINK
157              Reserved.
158
159       ENOMEM Not enough space.
160
161       ENOMSG No message of the desired type.
162
163       ENOPROTOOPT
164              Protocol not available.
165
166       ENOSPC No space left on device.
167
168       ENOSR  No STREAM resources.
169
170       ENOSTR Not a STREAM.
171
172       ENOSYS Functionality not supported.
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174       ENOTCONN
175              The socket is not connected.
176
177       ENOTDIR
178              Not a directory or a symbolic link to a directory.
179
180       ENOTEMPTY
181              Directory not empty.
182
183       ENOTRECOVERABLE
184              State not recoverable.
185
186       ENOTSOCK
187              Not a socket.
188
189       ENOTSUP
190              Not supported (may be the same value as [EOPNOTSUPP]).
191
192       ENOTTY Inappropriate I/O control operation.
193
194       ENXIO  No such device or address.
195
196       EOPNOTSUPP
197              Operation  not  supported  on  socket  (may be the same value as
198              [ENOTSUP]).
199
200       EOVERFLOW
201              Value too large to be stored in data type.
202
203       EOWNERDEAD
204              Previous owner died.
205
206       EPERM  Operation not permitted.
207
208       EPIPE  Broken pipe.
209
210       EPROTO Protocol error.
211
212       EPROTONOSUPPORT
213              Protocol not supported.
214
215       EPROTOTYPE
216              Protocol wrong type for socket.
217
218       ERANGE Result too large.
219
220       EROFS  Read-only file system.
221
222       ESPIPE Invalid seek.
223
224       ESRCH  No such process.
225
226       ESTALE Reserved.
227
228       ETIME  Stream ioctl() timeout.
229
230       ETIMEDOUT
231              Connection timed out.
232
233       ETXTBSY
234              Text file busy.
235
236       EWOULDBLOCK
237              Operation would block (may be the same value as [EAGAIN]).
238
239       EXDEV  Cross-device link.
240
241       The following sections are informative.
242

APPLICATION USAGE

244       Additional error numbers may be defined on conforming systems; see  the
245       System Interfaces volume of POSIX.1‐2017.
246

RATIONALE

248       None.
249

FUTURE DIRECTIONS

251       None.
252

COPYRIGHT

258       Portions of this text are reprinted and reproduced in  electronic  form
259       from  IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
260       table Operating System Interface (POSIX), The Open Group Base  Specifi‐
261       cations  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of
262       Electrical and Electronics Engineers, Inc and The Open Group.   In  the
263       event of any discrepancy between this version and the original IEEE and
264       The Open Group Standard, the original IEEE and The Open Group  Standard
265       is  the  referee document. The original Standard can be obtained online
266       at http://www.opengroup.org/unix/online.html .
267
268       Any typographical or formatting errors that appear  in  this  page  are
269       most likely to have been introduced during the conversion of the source
270       files to man page format. To report such errors,  see  https://www.ker‐
271       nel.org/doc/man-pages/reporting_bugs.html .
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275IEEE/The Open Group                  2017                          errno.h(0P)