1libcurl-errors(3) libcurl errors libcurl-errors(3)
2
6 libcurl-errors - error codes in libcurl
7
9 This man page includes most, if not all, available error codes in
10 libcurl. Why they occur and possibly what you can do to fix the prob‐
11 lem are also included.
12
14 Almost all "easy" interface functions return a CURLcode error code. No
15 matter what, using the curl_easy_setopt(3) option CURLOPT_ERROR‐
16 BUFFER(3) is a good idea as it will give you a human readable error
17 string that may offer more details about the cause of the error than
18 just the error code. curl_easy_strerror(3) can be called to get an er‐
19 ror string from a given CURLcode number.
20 CURLcode is one of the following:
22 CURLE_OK (0)
24 All fine. Proceed as usual.
25 CURLE_UNSUPPORTED_PROTOCOL (1)
27 The URL you passed to libcurl used a protocol that this libcurl
28 does not support. The support might be a compile-time option
29 that you did not use, it can be a misspelled protocol string or
30 just a protocol libcurl has no code for.
31 CURLE_FAILED_INIT (2)
33 Early initialization code failed. This is likely to be an inter‐
34 nal error or problem, or a resource problem where something fun‐
35 damental could not get done at init time.
36 CURLE_URL_MALFORMAT (3)
38 The URL was not properly formatted.
39 CURLE_NOT_BUILT_IN (4)
41 A requested feature, protocol or option was not found built-in
42 in this libcurl due to a build-time decision. This means that a
43 feature or option was not enabled or explicitly disabled when
44 libcurl was built and in order to get it to function you have to
45 get a rebuilt libcurl.
46 CURLE_COULDNT_RESOLVE_PROXY (5)
48 Couldn't resolve proxy. The given proxy host could not be re‐
49 solved.
50 CURLE_COULDNT_RESOLVE_HOST (6)
52 Couldn't resolve host. The given remote host was not resolved.
53 CURLE_COULDNT_CONNECT (7)
55 Failed to connect() to host or proxy.
56 CURLE_WEIRD_SERVER_REPLY (8)
58 The server sent data libcurl could not parse. This error code
59 was known as as CURLE_FTP_WEIRD_SERVER_REPLY before 7.51.0.
60 CURLE_REMOTE_ACCESS_DENIED (9)
62 We were denied access to the resource given in the URL. For FTP,
63 this occurs while trying to change to the remote directory.
64 CURLE_FTP_ACCEPT_FAILED (10)
66 While waiting for the server to connect back when an active FTP
67 session is used, an error code was sent over the control connec‐
68 tion or similar.
69 CURLE_FTP_WEIRD_PASS_REPLY (11)
71 After having sent the FTP password to the server, libcurl ex‐
72 pects a proper reply. This error code indicates that an unex‐
73 pected code was returned.
74 CURLE_FTP_ACCEPT_TIMEOUT (12)
76 During an active FTP session while waiting for the server to
77 connect, the CURLOPT_ACCEPTTIMEOUT_MS(3) (or the internal de‐
78 fault) timeout expired.
79 CURLE_FTP_WEIRD_PASV_REPLY (13)
81 libcurl failed to get a sensible result back from the server as
82 a response to either a PASV or a EPSV command. The server is
83 flawed.
84 CURLE_FTP_WEIRD_227_FORMAT (14)
86 FTP servers return a 227-line as a response to a PASV command.
87 If libcurl fails to parse that line, this return code is passed
88 back.
89 CURLE_FTP_CANT_GET_HOST (15)
91 An internal failure to lookup the host used for the new connec‐
92 tion.
93 CURLE_HTTP2 (16)
95 A problem was detected in the HTTP2 framing layer. This is some‐
96 what generic and can be one out of several problems, see the er‐
97 ror buffer for details.
98 CURLE_FTP_COULDNT_SET_TYPE (17)
100 Received an error when trying to set the transfer mode to binary
101 or ASCII.
102 CURLE_PARTIAL_FILE (18)
104 A file transfer was shorter or larger than expected. This hap‐
105 pens when the server first reports an expected transfer size,
106 and then delivers data that does not match the previously given
107 size.
108 CURLE_FTP_COULDNT_RETR_FILE (19)
110 This was either a weird reply to a 'RETR' command or a zero byte
111 transfer complete.
112 Obsolete error (20)
114 Not used in modern versions.
115 CURLE_QUOTE_ERROR (21)
117 When sending custom "QUOTE" commands to the remote server, one
118 of the commands returned an error code that was 400 or higher
119 (for FTP) or otherwise indicated unsuccessful completion of the
120 command.
121 CURLE_HTTP_RETURNED_ERROR (22)
123 This is returned if CURLOPT_FAILONERROR(3) is set TRUE and the
124 HTTP server returns an error code that is >= 400.
125 CURLE_WRITE_ERROR (23)
127 An error occurred when writing received data to a local file, or
128 an error was returned to libcurl from a write callback.
129 Obsolete error (24)
131 Not used in modern versions.
132 CURLE_UPLOAD_FAILED (25)
134 Failed starting the upload. For FTP, the server typically denied
135 the STOR command. The error buffer usually contains the server's
136 explanation for this.
137 CURLE_READ_ERROR (26)
139 There was a problem reading a local file or an error returned by
140 the read callback.
141 CURLE_OUT_OF_MEMORY (27)
143 A memory allocation request failed. This is serious badness and
144 things are severely screwed up if this ever occurs.
145 CURLE_OPERATION_TIMEDOUT (28)
147 Operation timeout. The specified time-out period was reached ac‐
148 cording to the conditions.
149 Obsolete error (29)
151 Not used in modern versions.
152 CURLE_FTP_PORT_FAILED (30)
154 The FTP PORT command returned error. This mostly happens when
155 you have not specified a good enough address for libcurl to use.
156 See CURLOPT_FTPPORT(3).
157 CURLE_FTP_COULDNT_USE_REST (31)
159 The FTP REST command returned error. This should never happen if
160 the server is sane.
161 Obsolete error (32)
163 Not used in modern versions.
164 CURLE_RANGE_ERROR (33)
166 The server does not support or accept range requests.
167 CURLE_HTTP_POST_ERROR (34)
169 This is an odd error that mainly occurs due to internal confu‐
170 sion.
171 CURLE_SSL_CONNECT_ERROR (35)
173 A problem occurred somewhere in the SSL/TLS handshake. You re‐
174 ally want the error buffer and read the message there as it pin‐
175 points the problem slightly more. Could be certificates (file
176 formats, paths, permissions), passwords, and others.
177 CURLE_BAD_DOWNLOAD_RESUME (36)
179 The download could not be resumed because the specified offset
180 was out of the file boundary.
181 CURLE_FILE_COULDNT_READ_FILE (37)
183 A file given with FILE:// could not be opened. Most likely be‐
184 cause the file path does not identify an existing file. Did you
185 check file permissions?
186 CURLE_LDAP_CANNOT_BIND (38)
188 LDAP cannot bind. LDAP bind operation failed.
189 CURLE_LDAP_SEARCH_FAILED (39)
191 LDAP search failed.
192 Obsolete error (40)
194 Not used in modern versions.
195 CURLE_FUNCTION_NOT_FOUND (41)
197 Function not found. A required zlib function was not found.
198 CURLE_ABORTED_BY_CALLBACK (42)
200 Aborted by callback. A callback returned "abort" to libcurl.
201 CURLE_BAD_FUNCTION_ARGUMENT (43)
203 A function was called with a bad parameter.
204 Obsolete error (44)
206 Not used in modern versions.
207 CURLE_INTERFACE_FAILED (45)
209 Interface error. A specified outgoing interface could not be
210 used. Set which interface to use for outgoing connections'
211 source IP address with CURLOPT_INTERFACE(3).
212 Obsolete error (46)
214 Not used in modern versions.
215 CURLE_TOO_MANY_REDIRECTS (47)
217 Too many redirects. When following redirects, libcurl hit the
218 maximum amount. Set your limit with CURLOPT_MAXREDIRS(3).
219 CURLE_UNKNOWN_OPTION (48)
221 An option passed to libcurl is not recognized/known. Refer to
222 the appropriate documentation. This is most likely a problem in
223 the program that uses libcurl. The error buffer might contain
224 more specific information about which exact option it concerns.
225 CURLE_SETOPT_OPTION_SYNTAX (49)
227 An option passed in to a setopt was wrongly formatted. See error
228 message for details about what option.
229 Obsolete errors (50-51)
231 Not used in modern versions.
232 CURLE_GOT_NOTHING (52)
234 Nothing was returned from the server, and under the circum‐
235 stances, getting nothing is considered an error.
236 CURLE_SSL_ENGINE_NOTFOUND (53)
238 The specified crypto engine was not found.
239 CURLE_SSL_ENGINE_SETFAILED (54)
241 Failed setting the selected SSL crypto engine as default.
242 CURLE_SEND_ERROR (55)
244 Failed sending network data.
245 CURLE_RECV_ERROR (56)
247 Failure with receiving network data.
248 Obsolete error (57)
250 Not used in modern versions.
251 CURLE_SSL_CERTPROBLEM (58)
253 problem with the local client certificate.
254 CURLE_SSL_CIPHER (59)
256 Couldn't use specified cipher.
257 CURLE_PEER_FAILED_VERIFICATION (60)
259 The remote server's SSL certificate or SSH md5 fingerprint was
260 deemed not OK. This error code has been unified with
261 CURLE_SSL_CACERT since 7.62.0. Its previous value was 51.
262 CURLE_BAD_CONTENT_ENCODING (61)
264 Unrecognized transfer encoding.
265 Obsolete error (62)
267 Not used in modern versions.
268 CURLE_FILESIZE_EXCEEDED (63)
270 Maximum file size exceeded.
271 CURLE_USE_SSL_FAILED (64)
273 Requested FTP SSL level failed.
274 CURLE_SEND_FAIL_REWIND (65)
276 When doing a send operation curl had to rewind the data to re‐
277 transmit, but the rewinding operation failed.
278 CURLE_SSL_ENGINE_INITFAILED (66)
280 Initiating the SSL Engine failed.
281 CURLE_LOGIN_DENIED (67)
283 The remote server denied curl to login (Added in 7.13.1)
284 CURLE_TFTP_NOTFOUND (68)
286 File not found on TFTP server.
287 CURLE_TFTP_PERM (69)
289 Permission problem on TFTP server.
290 CURLE_REMOTE_DISK_FULL (70)
292 Out of disk space on the server.
293 CURLE_TFTP_ILLEGAL (71)
295 Illegal TFTP operation.
296 CURLE_TFTP_UNKNOWNID (72)
298 Unknown TFTP transfer ID.
299 CURLE_REMOTE_FILE_EXISTS (73)
301 File already exists and will not be overwritten.
302 CURLE_TFTP_NOSUCHUSER (74)
304 This error should never be returned by a properly functioning
305 TFTP server.
306 Obsolete error (75-76)
308 Not used in modern versions.
309 CURLE_SSL_CACERT_BADFILE (77)
311 Problem with reading the SSL CA cert (path? access rights?)
312 CURLE_REMOTE_FILE_NOT_FOUND (78)
314 The resource referenced in the URL does not exist.
315 CURLE_SSH (79)
317 An unspecified error occurred during the SSH session.
318 CURLE_SSL_SHUTDOWN_FAILED (80)
320 Failed to shut down the SSL connection.
321 CURLE_AGAIN (81)
323 Socket is not ready for send/recv wait till it's ready and try
324 again. This return code is only returned from curl_easy_recv(3)
325 and curl_easy_send(3) (Added in 7.18.2)
326 CURLE_SSL_CRL_BADFILE (82)
328 Failed to load CRL file (Added in 7.19.0)
329 CURLE_SSL_ISSUER_ERROR (83)
331 Issuer check failed (Added in 7.19.0)
332 CURLE_FTP_PRET_FAILED (84)
334 The FTP server does not understand the PRET command at all or
335 does not support the given argument. Be careful when using CUR‐
336 LOPT_CUSTOMREQUEST(3), a custom LIST command will be sent with
337 PRET CMD before PASV as well. (Added in 7.20.0)
338 CURLE_RTSP_CSEQ_ERROR (85)
340 Mismatch of RTSP CSeq numbers.
341 CURLE_RTSP_SESSION_ERROR (86)
343 Mismatch of RTSP Session Identifiers.
344 CURLE_FTP_BAD_FILE_LIST (87)
346 Unable to parse FTP file list (during FTP wildcard downloading).
347 CURLE_CHUNK_FAILED (88)
349 Chunk callback reported error.
350 CURLE_NO_CONNECTION_AVAILABLE (89)
352 (For internal use only, will never be returned by libcurl) No
353 connection available, the session will be queued. (added in
354 7.30.0)
355 CURLE_SSL_PINNEDPUBKEYNOTMATCH (90)
357 Failed to match the pinned key specified with CURLOPT_PINNEDPUB‐
358 LICKEY(3).
359 CURLE_SSL_INVALIDCERTSTATUS (91)
361 Status returned failure when asked with CURLOPT_SSL_VERIFYSTA‐
362 TUS(3).
363 CURLE_HTTP2_STREAM (92)
365 Stream error in the HTTP/2 framing layer.
366 CURLE_RECURSIVE_API_CALL (93)
368 An API function was called from inside a callback.
369 CURLE_AUTH_ERROR (94)
371 An authentication function returned an error.
372 CURLE_HTTP3 (95)
374 A problem was detected in the HTTP/3 layer. This is somewhat
375 generic and can be one out of several problems, see the error
376 buffer for details.
377 CURLE_QUIC_CONNECT_ERROR (96)
379 QUIC connection error. This error may be caused by an SSL li‐
380 brary error. QUIC is the protocol used for HTTP/3 transfers.
381 CURLE_PROXY (97)
383 Proxy handshake error. CURLINFO_PROXY_ERROR(3) provides extra
384 details on the specific problem.
385 CURLE_SSL_CLIENTCERT (98)
387 SSL Client Certificate required.
388 CURLE_UNRECOVERABLE_POLL (99)
390 An internal call to poll() or select() returned error that is
391 not recoverable.
392 CURLE_OBSOLETE*
394 These error codes will never be returned. They were used in an
395 old libcurl version and are currently unused.
396
398 This is the generic return code used by functions in the libcurl multi
399 interface. Also consider curl_multi_strerror(3).
400 CURLM_CALL_MULTI_PERFORM (-1)
402 This is not really an error. It means you should call
403 curl_multi_perform(3) again without doing select() or similar in
404 between. Before version 7.20.0 (released on February 9 2010)
405 this could be returned by curl_multi_perform(3), but in later
406 versions this return code is never used.
407 CURLM_CALL_MULTI_SOCKET (-1)
409 An alias for CURLM_CALL_MULTI_PERFORM. Never returned by modern
410 libcurl versions.
411 CURLM_OK (0)
413 Things are fine.
414 CURLM_BAD_HANDLE (1)
416 The passed-in handle is not a valid CURLM handle.
417 CURLM_BAD_EASY_HANDLE (2)
419 An easy handle was not good/valid. It could mean that it is not
420 an easy handle at all, or possibly that the handle already is in
421 use by this or another multi handle.
422 CURLM_OUT_OF_MEMORY (3)
424 You are doomed.
425 CURLM_INTERNAL_ERROR (4)
427 This can only be returned if libcurl bugs. Please report it to
428 us!
429 CURLM_BAD_SOCKET (5)
431 The passed-in socket is not a valid one that libcurl already
432 knows about. (Added in 7.15.4)
433 CURLM_UNKNOWN_OPTION (6)
435 curl_multi_setopt() with unsupported option (Added in 7.15.4)
436 CURLM_ADDED_ALREADY (7)
438 An easy handle already added to a multi handle was attempted to
439 get added a second time. (Added in 7.32.1)
440 CURLM_RECURSIVE_API_CALL (8)
442 An API function was called from inside a callback.
443 CURLM_WAKEUP_FAILURE (9)
445 Wakeup is unavailable or failed.
446 CURLM_BAD_FUNCTION_ARGUMENT (10)
448 A function was called with a bad parameter.
449 CURLM_ABORTED_BY_CALLBACK (11)
451 A multi handle callback returned error.
452 CURLM_UNRECOVERABLE_POLL (12)
454 An internal call to poll() or select() returned error that is
455 not recoverable.
456
458 The "share" interface will return a CURLSHcode to indicate when an er‐
459 ror has occurred. Also consider curl_share_strerror(3).
460 CURLSHE_OK (0)
462 All fine. Proceed as usual.
463 CURLSHE_BAD_OPTION (1)
465 An invalid option was passed to the function.
466 CURLSHE_IN_USE (2)
468 The share object is currently in use.
469 CURLSHE_INVALID (3)
471 An invalid share object was passed to the function.
472 CURLSHE_NOMEM (4)
474 Not enough memory was available. (Added in 7.12.0)
475 CURLSHE_NOT_BUILT_IN (5)
477 The requested sharing could not be done because the library you
478 use do not have that particular feature enabled. (Added in
479 7.23.0)
480
482 The URL interface will return a CURLUcode to indicate when an error has
483 occurred. Also consider curl_url_strerror(3).
484 CURLUE_BAD_HANDLE (1)
486 An invalid CURLU pointer was passed as argument.
487 CURLUE_BAD_PARTPOINTER (2)
489 An invalid 'part' argument was passed as argument.
490 CURLUE_MALFORMED_INPUT (3)
492 A malformed input was passed to a URL API function.
493 CURLUE_BAD_PORT_NUMBER (4)
495 The port number was not a decimal number between 0 and 65535.
496 CURLUE_UNSUPPORTED_SCHEME (5)
498 This libcurl build does not support the given URL scheme.
499 CURLUE_URLDECODE (6)
501 URL decode error, most likely because of rubbish in the input.
502 CURLUE_OUT_OF_MEMORY (7)
504 A memory function failed.
505 CURLUE_USER_NOT_ALLOWED (8)
507 Credentials was passed in the URL when prohibited.
508 CURLUE_UNKNOWN_PART (9)
510 An unknown part ID was passed to a URL API function.
511 CURLUE_NO_SCHEME (10)
513 There is no scheme part in the URL.
514 CURLUE_NO_USER (11)
516 There is no user part in the URL.
517 CURLUE_NO_PASSWORD (12)
519 There is no password part in the URL.
520 CURLUE_NO_OPTIONS (13)
522 There is no options part in the URL.
523 CURLUE_NO_HOST (14)
525 There is no host part in the URL.
526 CURLUE_NO_PORT (15)
528 There is no port part in the URL.
529 CURLUE_NO_QUERY (16)
531 There is no query part in the URL.
532 CURLUE_NO_FRAGMENT (17)
534 There is no fragment part in the URL.
535 CURLUE_NO_ZONEID (18)
537 There is no zoneid set in the URL.
538 CURLUE_BAD_FILE_URL (19)
540 The file:// URL is invalid.
541 CURLUE_BAD_FRAGMENT (20)
543 The fragment part of the URL contained bad or invalid charac‐
544 ters.
545 CURLUE_BAD_HOSTNAME (21)
547 The hostname contained bad or invalid characters.
548 CURLUE_BAD_IPV6 (22)
550 The IPv6 address hostname contained bad or invalid characters.
551 CURLUE_BAD_LOGIN (23)
553 The login part of the URL contained bad or invalid characters.
554 CURLUE_BAD_PASSWORD (24)
556 The password part of the URL contained bad or invalid charac‐
557 ters.
558 CURLUE_BAD_PATH (25)
560 The path part of the URL contained bad or invalid characters.
561 CURLUE_BAD_QUERY (26)
563 The query part of the URL contained bad or invalid characters.
564 CURLUE_BAD_SCHEME (27)
566 The scheme part of the URL contained bad or invalid characters.
567 CURLUE_BAD_SLASHES (28)
569 The URL contained an invalid number of slashes.
570 CURLUE_BAD_USER (29)
572 The user part of the URL contained bad or invalid characters.
573
575 curl_easy_strerror(3), curl_multi_strerror(3), curl_share_strerror(3),
576 curl_url_strerror(3), CURLOPT_ERRORBUFFER(3), CURLOPT_VERBOSE(3), CUR‐
577 LOPT_DEBUGFUNCTION(3)
578libcurl 7.85.0 June 29, 2022 libcurl-errors(3)