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 CURLE_QUOTE_ERROR (21)
114 When sending custom "QUOTE" commands to the remote server, one
115 of the commands returned an error code that was 400 or higher
116 (for FTP) or otherwise indicated unsuccessful completion of the
117 command.
118 CURLE_HTTP_RETURNED_ERROR (22)
120 This is returned if CURLOPT_FAILONERROR(3) is set TRUE and the
121 HTTP server returns an error code that is >= 400.
122 CURLE_WRITE_ERROR (23)
124 An error occurred when writing received data to a local file, or
125 an error was returned to libcurl from a write callback.
126 CURLE_UPLOAD_FAILED (25)
128 Failed starting the upload. For FTP, the server typically denied
129 the STOR command. The error buffer usually contains the server's
130 explanation for this.
131 CURLE_READ_ERROR (26)
133 There was a problem reading a local file or an error returned by
134 the read callback.
135 CURLE_OUT_OF_MEMORY (27)
137 A memory allocation request failed. This is serious badness and
138 things are severely screwed up if this ever occurs.
139 CURLE_OPERATION_TIMEDOUT (28)
141 Operation timeout. The specified time-out period was reached ac‐
142 cording to the conditions.
143 CURLE_FTP_PORT_FAILED (30)
145 The FTP PORT command returned error. This mostly happens when
146 you have not specified a good enough address for libcurl to use.
147 See CURLOPT_FTPPORT(3).
148 CURLE_FTP_COULDNT_USE_REST (31)
150 The FTP REST command returned error. This should never happen if
151 the server is sane.
152 CURLE_RANGE_ERROR (33)
154 The server does not support or accept range requests.
155 CURLE_HTTP_POST_ERROR (34)
157 This is an odd error that mainly occurs due to internal confu‐
158 sion.
159 CURLE_SSL_CONNECT_ERROR (35)
161 A problem occurred somewhere in the SSL/TLS handshake. You re‐
162 ally want the error buffer and read the message there as it pin‐
163 points the problem slightly more. Could be certificates (file
164 formats, paths, permissions), passwords, and others.
165 CURLE_BAD_DOWNLOAD_RESUME (36)
167 The download could not be resumed because the specified offset
168 was out of the file boundary.
169 CURLE_FILE_COULDNT_READ_FILE (37)
171 A file given with FILE:// could not be opened. Most likely be‐
172 cause the file path does not identify an existing file. Did you
173 check file permissions?
174 CURLE_LDAP_CANNOT_BIND (38)
176 LDAP cannot bind. LDAP bind operation failed.
177 CURLE_LDAP_SEARCH_FAILED (39)
179 LDAP search failed.
180 CURLE_FUNCTION_NOT_FOUND (41)
182 Function not found. A required zlib function was not found.
183 CURLE_ABORTED_BY_CALLBACK (42)
185 Aborted by callback. A callback returned "abort" to libcurl.
186 CURLE_BAD_FUNCTION_ARGUMENT (43)
188 A function was called with a bad parameter.
189 CURLE_INTERFACE_FAILED (45)
191 Interface error. A specified outgoing interface could not be
192 used. Set which interface to use for outgoing connections'
193 source IP address with CURLOPT_INTERFACE(3).
194 CURLE_TOO_MANY_REDIRECTS (47)
196 Too many redirects. When following redirects, libcurl hit the
197 maximum amount. Set your limit with CURLOPT_MAXREDIRS(3).
198 CURLE_UNKNOWN_OPTION (48)
200 An option passed to libcurl is not recognized/known. Refer to
201 the appropriate documentation. This is most likely a problem in
202 the program that uses libcurl. The error buffer might contain
203 more specific information about which exact option it concerns.
204 CURLE_SETOPT_OPTION_SYNTAX (49)
206 An option passed in to a setopt was wrongly formatted. See error
207 message for details about what option.
208 CURLE_GOT_NOTHING (52)
210 Nothing was returned from the server, and under the circum‐
211 stances, getting nothing is considered an error.
212 CURLE_SSL_ENGINE_NOTFOUND (53)
214 The specified crypto engine was not found.
215 CURLE_SSL_ENGINE_SETFAILED (54)
217 Failed setting the selected SSL crypto engine as default.
218 CURLE_SEND_ERROR (55)
220 Failed sending network data.
221 CURLE_RECV_ERROR (56)
223 Failure with receiving network data.
224 CURLE_SSL_CERTPROBLEM (58)
226 problem with the local client certificate.
227 CURLE_SSL_CIPHER (59)
229 Couldn't use specified cipher.
230 CURLE_PEER_FAILED_VERIFICATION (60)
232 The remote server's SSL certificate or SSH md5 fingerprint was
233 deemed not OK. This error code has been unified with
234 CURLE_SSL_CACERT since 7.62.0. Its previous value was 51.
235 CURLE_BAD_CONTENT_ENCODING (61)
237 Unrecognized transfer encoding.
238 CURLE_LDAP_INVALID_URL (62)
240 This error code is deprecated since 7.82.0 and cannot be re‐
241 turned anymore.
242 CURLE_FILESIZE_EXCEEDED (63)
244 Maximum file size exceeded.
245 CURLE_USE_SSL_FAILED (64)
247 Requested FTP SSL level failed.
248 CURLE_SEND_FAIL_REWIND (65)
250 When doing a send operation curl had to rewind the data to re‐
251 transmit, but the rewinding operation failed.
252 CURLE_SSL_ENGINE_INITFAILED (66)
254 Initiating the SSL Engine failed.
255 CURLE_LOGIN_DENIED (67)
257 The remote server denied curl to login (Added in 7.13.1)
258 CURLE_TFTP_NOTFOUND (68)
260 File not found on TFTP server.
261 CURLE_TFTP_PERM (69)
263 Permission problem on TFTP server.
264 CURLE_REMOTE_DISK_FULL (70)
266 Out of disk space on the server.
267 CURLE_TFTP_ILLEGAL (71)
269 Illegal TFTP operation.
270 CURLE_TFTP_UNKNOWNID (72)
272 Unknown TFTP transfer ID.
273 CURLE_REMOTE_FILE_EXISTS (73)
275 File already exists and will not be overwritten.
276 CURLE_TFTP_NOSUCHUSER (74)
278 This error should never be returned by a properly functioning
279 TFTP server.
280 CURLE_CONV_FAILED (75)
282 Character conversion failed.
283 CURLE_CONV_REQD (76)
285 Caller must register conversion callbacks.
286 CURLE_SSL_CACERT_BADFILE (77)
288 Problem with reading the SSL CA cert (path? access rights?)
289 CURLE_REMOTE_FILE_NOT_FOUND (78)
291 The resource referenced in the URL does not exist.
292 CURLE_SSH (79)
294 An unspecified error occurred during the SSH session.
295 CURLE_SSL_SHUTDOWN_FAILED (80)
297 Failed to shut down the SSL connection.
298 CURLE_AGAIN (81)
300 Socket is not ready for send/recv wait till it's ready and try
301 again. This return code is only returned from curl_easy_recv(3)
302 and curl_easy_send(3) (Added in 7.18.2)
303 CURLE_SSL_CRL_BADFILE (82)
305 Failed to load CRL file (Added in 7.19.0)
306 CURLE_SSL_ISSUER_ERROR (83)
308 Issuer check failed (Added in 7.19.0)
309 CURLE_FTP_PRET_FAILED (84)
311 The FTP server does not understand the PRET command at all or
312 does not support the given argument. Be careful when using CUR‐
313 LOPT_CUSTOMREQUEST(3), a custom LIST command will be sent with
314 PRET CMD before PASV as well. (Added in 7.20.0)
315 CURLE_RTSP_CSEQ_ERROR (85)
317 Mismatch of RTSP CSeq numbers.
318 CURLE_RTSP_SESSION_ERROR (86)
320 Mismatch of RTSP Session Identifiers.
321 CURLE_FTP_BAD_FILE_LIST (87)
323 Unable to parse FTP file list (during FTP wildcard downloading).
324 CURLE_CHUNK_FAILED (88)
326 Chunk callback reported error.
327 CURLE_NO_CONNECTION_AVAILABLE (89)
329 (For internal use only, will never be returned by libcurl) No
330 connection available, the session will be queued. (added in
331 7.30.0)
332 CURLE_SSL_PINNEDPUBKEYNOTMATCH (90)
334 Failed to match the pinned key specified with CURLOPT_PINNEDPUB‐
335 LICKEY(3).
336 CURLE_SSL_INVALIDCERTSTATUS (91)
338 Status returned failure when asked with CURLOPT_SSL_VERIFYSTA‐
339 TUS(3).
340 CURLE_HTTP2_STREAM (92)
342 Stream error in the HTTP/2 framing layer.
343 CURLE_RECURSIVE_API_CALL (93)
345 An API function was called from inside a callback.
346 CURLE_AUTH_ERROR (94)
348 An authentication function returned an error.
349 CURLE_HTTP3 (95)
351 A problem was detected in the HTTP/3 layer. This is somewhat
352 generic and can be one out of several problems, see the error
353 buffer for details.
354 CURLE_QUIC_CONNECT_ERROR (96)
356 QUIC connection error. This error may be caused by an SSL li‐
357 brary error. QUIC is the protocol used for HTTP/3 transfers.
358 CURLE_SSL_CLIENTCERT (98)
360 SSL Client Certificate required.
361 CURLE_OBSOLETE*
363 These error codes will never be returned. They were used in an
364 old libcurl version and are currently unused.
365
367 This is the generic return code used by functions in the libcurl multi
368 interface. Also consider curl_multi_strerror(3).
369 CURLM_CALL_MULTI_PERFORM (-1)
371 This is not really an error. It means you should call
372 curl_multi_perform(3) again without doing select() or similar in
373 between. Before version 7.20.0 (released on February 9 2010)
374 this could be returned by curl_multi_perform(3), but in later
375 versions this return code is never used.
376 CURLM_CALL_MULTI_SOCKET (-1)
378 An alias for CURLM_CALL_MULTI_PERFORM. Never returned by modern
379 libcurl versions.
380 CURLM_OK (0)
382 Things are fine.
383 CURLM_BAD_HANDLE (1)
385 The passed-in handle is not a valid CURLM handle.
386 CURLM_BAD_EASY_HANDLE (2)
388 An easy handle was not good/valid. It could mean that it is not
389 an easy handle at all, or possibly that the handle already is in
390 use by this or another multi handle.
391 CURLM_OUT_OF_MEMORY (3)
393 You are doomed.
394 CURLM_INTERNAL_ERROR (4)
396 This can only be returned if libcurl bugs. Please report it to
397 us!
398 CURLM_BAD_SOCKET (5)
400 The passed-in socket is not a valid one that libcurl already
401 knows about. (Added in 7.15.4)
402 CURLM_UNKNOWN_OPTION (6)
404 curl_multi_setopt() with unsupported option (Added in 7.15.4)
405 CURLM_ADDED_ALREADY (7)
407 An easy handle already added to a multi handle was attempted to
408 get added a second time. (Added in 7.32.1)
409 CURLM_RECURSIVE_API_CALL (8)
411 An API function was called from inside a callback.
412 CURLM_WAKEUP_FAILURE (9)
414 Wakeup is unavailable or failed.
415 CURLM_BAD_FUNCTION_ARGUMENT (10)
417 A function was called with a bad parameter.
418 CURLM_ABORTED_BY_CALLBACK (11)
420 A multi handle callback returned error.
421
423 The "share" interface will return a CURLSHcode to indicate when an er‐
424 ror has occurred. Also consider curl_share_strerror(3).
425 CURLSHE_OK (0)
427 All fine. Proceed as usual.
428 CURLSHE_BAD_OPTION (1)
430 An invalid option was passed to the function.
431 CURLSHE_IN_USE (2)
433 The share object is currently in use.
434 CURLSHE_INVALID (3)
436 An invalid share object was passed to the function.
437 CURLSHE_NOMEM (4)
439 Not enough memory was available. (Added in 7.12.0)
440 CURLSHE_NOT_BUILT_IN (5)
442 The requested sharing could not be done because the library you
443 use do not have that particular feature enabled. (Added in
444 7.23.0)
445
447 The URL interface will return a CURLUcode to indicate when an error has
448 occurred. Also consider curl_url_strerror(3).
449 CURLUE_BAD_HANDLE (1)
451 An invalid CURLU pointer was passed as argument.
452 CURLUE_BAD_PARTPOINTER (2)
454 An invalid 'part' argument was passed as argument.
455 CURLUE_MALFORMED_INPUT (3)
457 A malformed input was passed to a URL API function.
458 CURLUE_BAD_PORT_NUMBER (4)
460 The port number was not a decimal number between 0 and 65535.
461 CURLUE_UNSUPPORTED_SCHEME (5)
463 This libcurl build does not support the given URL scheme.
464 CURLUE_URLDECODE (6)
466 URL decode error, most likely because of rubbish in the input.
467 CURLUE_OUT_OF_MEMORY (7)
469 A memory function failed.
470 CURLUE_USER_NOT_ALLOWED (8)
472 Credentials was passed in the URL when prohibited.
473 CURLUE_UNKNOWN_PART (9)
475 An unknown part ID was passed to a URL API function.
476 CURLUE_NO_SCHEME (10)
478 There is no scheme part in the URL.
479 CURLUE_NO_USER (11)
481 There is no user part in the URL.
482 CURLUE_NO_PASSWORD (12)
484 There is no password part in the URL.
485 CURLUE_NO_OPTIONS (13)
487 There is no options part in the URL.
488 CURLUE_NO_HOST (14)
490 There is no host part in the URL.
491 CURLUE_NO_PORT (15)
493 There is no port part in the URL.
494 CURLUE_NO_QUERY (16)
496 There is no query part in the URL.
497 CURLUE_NO_FRAGMENT (17)
499 There is no fragment part in the URL.
500 CURLUE_NO_ZONEID (18)
502 There is no zoneid set in the URL.
503 CURLUE_BAD_FILE_URL (19)
505 The file:// URL is invalid.
506 CURLUE_BAD_FRAGMENT (20)
508 The fragment part of the URL contained bad or invalid charac‐
509 ters.
510 CURLUE_BAD_HOSTNAME (21)
512 The hostname contained bad or invalid characters.
513 CURLUE_BAD_IPV6 (22)
515 The IPv6 address hostname contained bad or invalid characters.
516 CURLUE_BAD_LOGIN (23)
518 The login part of the URL contained bad or invalid characters.
519 CURLUE_BAD_PASSWORD (24)
521 The password part of the URL contained bad or invalid charac‐
522 ters.
523 CURLUE_BAD_PATH (25)
525 The path part of the URL contained bad or invalid characters.
526 CURLUE_BAD_QUERY (26)
528 The query part of the URL contained bad or invalid characters.
529 CURLUE_BAD_SCHEME (27)
531 The scheme part of the URL contained bad or invalid characters.
532 CURLUE_BAD_SLASHES (28)
534 The URL contained an invalid number of slashes.
535 CURLUE_BAD_USER (29)
537 The user part of the URL contained bad or invalid characters.
538
540 curl_easy_strerror(3), curl_multi_strerror(3), curl_share_strerror(3),
541 curl_url_strerror(3), CURLOPT_ERRORBUFFER(3), CURLOPT_VERBOSE(3), CUR‐
542 LOPT_DEBUGFUNCTION(3)
543libcurl 7.82.0 January 09, 2022 libcurl-errors(3)