1:未支持的协议。此版cURL不支持这一协议。
2:初始化失败。
3:URL格式错误。语法不正确。
5:无法解析代理。无法解析给定代理主机。
6:无法解析主机。无法解析给定的远程主机。
7:无法连接到主机。
8:FTP非正常的服务器应答。cURL无法解析服务器发送的数据。
9:FTP访问被拒绝。服务器拒绝登入或无法获取您想要的特定资源或目录。最有可能的是您试图进入一个在此服务器上不存在的目录。
11:FTP 非正常的PASS回复。cURL无法解析发送到PASS请求的应答。
13:FTP 非正常的的PASV应答，cURL无法解析发送到PASV请求的应答。
14:FTP非正常的227格式。cURL无法解析服务器发送的227行。
15:FTP无法连接到主机。无法解析在227行中获取的主机IP。
17:FTP无法设定为二进制传输。无法改变传输方式到二进制。
18:部分文件。只有部分文件被传输。
19:FTP不能下载/访问给定的文件， RETR (或类似)命令失败。
21:FTP quote错误。quote命令从服务器返回错误。
22:HTTP 找不到网页。找不到所请求的URL或返回另一个HTTP 400或以上错误。此返回代码只出现在使用了-f/–fail选项以后。
23:写入错误。cURL无法向本地文件系统或类似目的写入数据。
25:FTP 无法STOR文件。服务器拒绝了用于FTP上传的STOR操作。
26:读错误。各类读取问题。
27:内存不足。内存分配请求失败。
28:操作超时。到达指定的超时期限条件。
30:FTP PORT失败。PORT命令失败。并非所有的FTP服务器支持PORT命令，请尝试使用被动(PASV)传输代替！
31:FTP无法使用REST命令。REST命令失败。此命令用来恢复的FTP传输。
33:HTTP range错误。range “命令”不起作用。
34:HTTP POST错误。内部POST请求产生错误。
35:SSL连接错误。SSL握手失败。
36:FTP 续传损坏。不能继续早些时候被中止的下载。
37:文件无法读取。无法打开文件。权限问题？
38:LDAP 无法绑定。LDAP绑定(bind)操作失败。
39:LDAP 搜索失败。
41:功能无法找到。无法找到必要的LDAP功能。
42:由回调终止。应用程序告知cURL终止运作。
43:内部错误。由一个不正确参数调用了功能。
45:接口错误。指定的外发接口无法使用。
47:过多的重定向。cURL达到了跟随重定向设定的最大限额跟
48:指定了未知TELNET选项。
49:不合式的telnet选项。
51:peer的SSL证书或SSH的MD5指纹没有确定。
52:服务器无任何应答，该情况在此处被认为是一个错误。
53:找不到SSL加密引擎。
54:无法将SSL加密引擎设置为默认。
55:发送网络数据失败。
56:在接收网络数据时失败。
58:本地证书有问题。
59:无法使用指定的SSL密码。
60:peer证书无法被已知的CA证书验证。
61:无法辨识的传输编码。
62:无效的LDAP URL。
63:超过最大文件尺寸。
64:要求的FTP的SSL水平失败。
65:发送此数据需要的回卷(rewind)失败。
66:初始化SSL引擎失败。
67:用户名、密码或类似的信息未被接受，cURL登录失败。
68:在TFTP服务器上找不到文件。
69:TFTP服务器权限有问题。
70:TFTP服务器磁盘空间不足。
71:非法的TFTP操作。
72:未知TFTP传输编号(ID)。
73:文件已存在(TFTP) 。
74:无此用户(TFTP) 。
75:字符转换失败。
76:需要字符转换功能。
77:读SSL证书出现问题(路径？访问权限？ ) 。
78:URL中引用的资源不存在。
79:SSH会话期间发生一个未知错误。
80:未能关闭SSL连接。
82:无法加载CRL文件，丢失或格式不正确(在7.19.0版中增加 ) 。
83:签发检查失败(在7.19.0版中增加 ) 。
https://curl.se/libcurl/c/libcurl-errors.html
http://s1.in.aiwaly.com/M00/docs/curl/libcurl-ErrorCodes.mhtml
libcurl error codes
Name
libcurl-errors - error codes in libcurl
Description
This man page includes most, if not all, available error codes in libcurl. Why they occur and possibly what you can do to fix the problem are also included.
Curlcode
Almost all “easy” interface functions return a CURLcode error code. No matter what, using the curl_easy_setopt option CURLOPT_ERRORBUFFER is a good idea as it will give you a human readable error string that may offer more details about the cause of the error than just the error code. curl_easy_strerror can be called to get an error string from a given CURLcode number.
CURLcode is one of the following:
CURLE_OK (0)
All fine. Proceed as usual.
CURLE_UNSUPPORTED_PROTOCOL (1)
The URL you passed to libcurl used a protocol that this libcurl does not support. The support might be a compile-time option that you did not use, it can be a misspelled protocol string or just a protocol libcurl has no code for.
CURLE_FAILED_INIT (2)
Early initialization code failed. This is likely to be an internal error or problem, or a resource problem where something fundamental could not get done at init time.
CURLE_URL_MALFORMAT (3)
The URL was not properly formatted.
CURLE_NOT_BUILT_IN (4)
A requested feature, protocol or option was not found built-in in this libcurl due to a build-time decision. This means that a feature or option was not enabled or explicitly disabled when libcurl was built and in order to get it to function you have to get a rebuilt libcurl.
CURLE_COULDNT_RESOLVE_PROXY (5)
Could not resolve proxy. The given proxy host could not be resolved.
CURLE_COULDNT_RESOLVE_HOST (6)
Could not resolve host. The given remote host was not resolved.
CURLE_COULDNT_CONNECT (7)
Failed to connect() to host or proxy.
CURLE_WEIRD_SERVER_REPLY (8)
The server sent data libcurl could not parse. This error code was known as as CURLE_FTP_WEIRD_SERVER_REPLY before 7.51.0.
CURLE_REMOTE_ACCESS_DENIED (9)
We were denied access to the resource given in the URL. For FTP, this occurs while trying to change to the remote directory.
CURLE_FTP_ACCEPT_FAILED (10)
While waiting for the server to connect back when an active FTP session is used, an error code was sent over the control connection or similar.
CURLE_FTP_WEIRD_PASS_REPLY (11)
After having sent the FTP password to the server, libcurl expects a proper reply. This error code indicates that an unexpected code was returned.
CURLE_FTP_ACCEPT_TIMEOUT (12)
During an active FTP session while waiting for the server to connect, the CURLOPT_ACCEPTTIMEOUT_MS (or the internal default) timeout expired.
CURLE_FTP_WEIRD_PASV_REPLY (13)
libcurl failed to get a sensible result back from the server as a response to either a PASV or a EPSV command. The server is flawed.
CURLE_FTP_WEIRD_227_FORMAT (14)
FTP servers return a 227-line as a response to a PASV command. If libcurl fails to parse that line, this return code is passed back.
CURLE_FTP_CANT_GET_HOST (15)
An internal failure to lookup the host used for the new connection.
CURLE_HTTP2 (16)
A problem was detected in the HTTP2 framing layer. This is somewhat generic and can be one out of several problems, see the error buffer for details.
CURLE_FTP_COULDNT_SET_TYPE (17)
Received an error when trying to set the transfer mode to binary or ASCII.
CURLE_PARTIAL_FILE (18)
A file transfer was shorter or larger than expected. This happens when the server first reports an expected transfer size, and then delivers data that does not match the previously given size.
CURLE_FTP_COULDNT_RETR_FILE (19)
This was either a weird reply to a ‘RETR’ command or a zero byte transfer complete.
Obsolete error (20)
Not used in modern versions.
CURLE_QUOTE_ERROR (21)
When sending custom “QUOTE” commands to the remote server, one of the commands returned an error code that was 400 or higher (for FTP) or otherwise indicated unsuccessful completion of the command.
CURLE_HTTP_RETURNED_ERROR (22)
This is returned if CURLOPT_FAILONERROR is set TRUE and the HTTP server returns an error code that is >= 400.
CURLE_WRITE_ERROR (23)
An error occurred when writing received data to a local file, or an error was returned to libcurl from a write callback.
Obsolete error (24)
Not used in modern versions.
CURLE_UPLOAD_FAILED (25)
Failed starting the upload. For FTP, the server typically denied the STOR command. The error buffer usually contains the server’s explanation for this.
CURLE_READ_ERROR (26)
There was a problem reading a local file or an error returned by the read callback.
CURLE_OUT_OF_MEMORY (27)
A memory allocation request failed. This is serious badness and things are severely screwed up if this ever occurs.
CURLE_OPERATION_TIMEDOUT (28)
Operation timeout. The specified time-out period was reached according to the conditions.
Obsolete error (29)
Not used in modern versions.
CURLE_FTP_PORT_FAILED (30)
The FTP PORT command returned error. This mostly happens when you have not specified a good enough address for libcurl to use. See CURLOPT_FTPPORT.
CURLE_FTP_COULDNT_USE_REST (31)
The FTP REST command returned error. This should never happen if the server is sane.
Obsolete error (32)
Not used in modern versions.
CURLE_RANGE_ERROR (33)
The server does not support or accept range requests.
CURLE_HTTP_POST_ERROR (34)
This is an odd error that mainly occurs due to internal confusion.
CURLE_SSL_CONNECT_ERROR (35)
A problem occurred somewhere in the SSL/TLS handshake. You really want the error buffer and read the message there as it pinpoints the problem slightly more. Could be certificates (file formats, paths, permissions), passwords, and others.
CURLE_BAD_DOWNLOAD_RESUME (36)
The download could not be resumed because the specified offset was out of the file boundary.
CURLE_FILE_COULDNT_READ_FILE (37)
A file given with FILE:// could not be opened. Most likely because the file path does not identify an existing file. Did you check file permissions?
CURLE_LDAP_CANNOT_BIND (38)
LDAP cannot bind. LDAP bind operation failed.
CURLE_LDAP_SEARCH_FAILED (39)
LDAP search failed.
Obsolete error (40)
Not used in modern versions.
CURLE_FUNCTION_NOT_FOUND (41)
Function not found. A required zlib function was not found.
CURLE_ABORTED_BY_CALLBACK (42)
Aborted by callback. A callback returned “abort” to libcurl.
CURLE_BAD_FUNCTION_ARGUMENT (43)
A function was called with a bad parameter.
Obsolete error (44)
Not used in modern versions.
CURLE_INTERFACE_FAILED (45)
Interface error. A specified outgoing interface could not be used. Set which interface to use for outgoing connections’ source IP address with CURLOPT_INTERFACE.
Obsolete error (46)
Not used in modern versions.
CURLE_TOO_MANY_REDIRECTS (47)
Too many redirects. When following redirects, libcurl hit the maximum amount. Set your limit with CURLOPT_MAXREDIRS.
CURLE_UNKNOWN_OPTION (48)
An option passed to libcurl is not recognized/known. Refer to the appropriate documentation. This is most likely a problem in the program that uses libcurl. The error buffer might contain more specific information about which exact option it concerns.
CURLE_SETOPT_OPTION_SYNTAX (49)
An option passed in to a setopt was wrongly formatted. See error message for details about what option.
Obsolete errors (50-51)
Not used in modern versions.
CURLE_GOT_NOTHING (52)
Nothing was returned from the server, and under the circumstances, getting nothing is considered an error.
CURLE_SSL_ENGINE_NOTFOUND (53)
The specified crypto engine was not found.
CURLE_SSL_ENGINE_SETFAILED (54)
Failed setting the selected SSL crypto engine as default.
CURLE_SEND_ERROR (55)
Failed sending network data.
CURLE_RECV_ERROR (56)
Failure with receiving network data.
Obsolete error (57)
Not used in modern versions.
CURLE_SSL_CERTPROBLEM (58)
problem with the local client certificate.
CURLE_SSL_CIPHER (59)
Could not use specified cipher.
CURLE_PEER_FAILED_VERIFICATION (60)
The remote server’s SSL certificate or SSH fingerprint was deemed not OK. This error code has been unified with CURLE_SSL_CACERT since 7.62.0. Its previous value was 51.
CURLE_BAD_CONTENT_ENCODING (61)
Unrecognized transfer encoding.
Obsolete error (62)
Not used in modern versions.
CURLE_FILESIZE_EXCEEDED (63)
Maximum file size exceeded.
CURLE_USE_SSL_FAILED (64)
Requested FTP SSL level failed.
CURLE_SEND_FAIL_REWIND (65)
When doing a send operation curl had to rewind the data to retransmit, but the rewinding operation failed.
CURLE_SSL_ENGINE_INITFAILED (66)
Initiating the SSL Engine failed.
CURLE_LOGIN_DENIED (67)
The remote server denied curl to login (Added in 7.13.1)
CURLE_TFTP_NOTFOUND (68)
File not found on TFTP server.
CURLE_TFTP_PERM (69)
Permission problem on TFTP server.
CURLE_REMOTE_DISK_FULL (70)
Out of disk space on the server.
CURLE_TFTP_ILLEGAL (71)
Illegal TFTP operation.
CURLE_TFTP_UNKNOWNID (72)
Unknown TFTP transfer ID.
CURLE_REMOTE_FILE_EXISTS (73)
File already exists and will not be overwritten.
CURLE_TFTP_NOSUCHUSER (74)
This error should never be returned by a properly functioning TFTP server.
Obsolete error (75-76)
Not used in modern versions.
CURLE_SSL_CACERT_BADFILE (77)
Problem with reading the SSL CA cert (path? access rights?)
CURLE_REMOTE_FILE_NOT_FOUND (78)
The resource referenced in the URL does not exist.
CURLE_SSH (79)
An unspecified error occurred during the SSH session.
CURLE_SSL_SHUTDOWN_FAILED (80)
Failed to shut down the SSL connection.
CURLE_AGAIN (81)
Socket is not ready for send/recv wait till it’s ready and try again. This return code is only returned from curl_easy_recv and curl_easy_send (Added in 7.18.2)
CURLE_SSL_CRL_BADFILE (82)
Failed to load CRL file (Added in 7.19.0)
CURLE_SSL_ISSUER_ERROR (83)
Issuer check failed (Added in 7.19.0)
CURLE_FTP_PRET_FAILED (84)
The FTP server does not understand the PRET command at all or does not support the given argument. Be careful when using CURLOPT_CUSTOMREQUEST, a custom LIST command will be sent with the PRET command before PASV as well. (Added in 7.20.0)
CURLE_RTSP_CSEQ_ERROR (85)
Mismatch of RTSP CSeq numbers.
CURLE_RTSP_SESSION_ERROR (86)
Mismatch of RTSP Session Identifiers.
CURLE_FTP_BAD_FILE_LIST (87)
Unable to parse FTP file list (during FTP wildcard downloading).
CURLE_CHUNK_FAILED (88)
Chunk callback reported error.
CURLE_NO_CONNECTION_AVAILABLE (89)
(For internal use only, will never be returned by libcurl) No connection available, the session will be queued. (added in 7.30.0)
CURLE_SSL_PINNEDPUBKEYNOTMATCH (90)
Failed to match the pinned key specified with CURLOPT_PINNEDPUBLICKEY.
CURLE_SSL_INVALIDCERTSTATUS (91)
Status returned failure when asked with CURLOPT_SSL_VERIFYSTATUS.
CURLE_HTTP2_STREAM (92)
Stream error in the HTTP/2 framing layer.
CURLE_RECURSIVE_API_CALL (93)
An API function was called from inside a callback.
CURLE_AUTH_ERROR (94)
An authentication function returned an error.
CURLE_HTTP3 (95)
A problem was detected in the HTTP/3 layer. This is somewhat generic and can be one out of several problems, see the error buffer for details.
CURLE_QUIC_CONNECT_ERROR (96)
QUIC connection error. This error may be caused by an SSL library error. QUIC is the protocol used for HTTP/3 transfers.
CURLE_PROXY (97)
Proxy handshake error. CURLINFO_PROXY_ERROR provides extra details on the specific problem.
CURLE_SSL_CLIENTCERT (98)
SSL Client Certificate required.
CURLE_UNRECOVERABLE_POLL (99)
An internal call to poll() or select() returned error that is not recoverable.
CURLE_OBSOLETE*
These error codes will never be returned. They were used in an old libcurl version and are currently unused.
Curlmcode
This is the generic return code used by functions in the libcurl multi interface. Also consider curl_multi_strerror.
CURLM_CALL_MULTI_PERFORM (-1)
This is not really an error. It means you should call curl_multi_perform again without doing select() or similar in between. Before version 7.20.0 (released on February 9 2010) this could be returned by curl_multi_perform, but in later versions this return code is never used.
CURLM_CALL_MULTI_SOCKET (-1)
An alias for CURLM_CALL_MULTI_PERFORM. Never returned by modern libcurl versions.
CURLM_OK (0)
Things are fine.
CURLM_BAD_HANDLE (1)
The passed-in handle is not a valid CURLM handle.
CURLM_BAD_EASY_HANDLE (2)
An easy handle was not good/valid. It could mean that it is not an easy handle at all, or possibly that the handle already is in use by this or another multi handle.
CURLM_OUT_OF_MEMORY (3)
You are doomed.
CURLM_INTERNAL_ERROR (4)
This can only be returned if libcurl bugs. Please report it to us!
CURLM_BAD_SOCKET (5)
The passed-in socket is not a valid one that libcurl already knows about. (Added in 7.15.4)
CURLM_UNKNOWN_OPTION (6)
curl_multi_setopt() with unsupported option (Added in 7.15.4)
CURLM_ADDED_ALREADY (7)
An easy handle already added to a multi handle was attempted to get added a second time. (Added in 7.32.1)
CURLM_RECURSIVE_API_CALL (8)
An API function was called from inside a callback.
CURLM_WAKEUP_FAILURE (9)
Wake up is unavailable or failed.
CURLM_BAD_FUNCTION_ARGUMENT (10)
A function was called with a bad parameter.
CURLM_ABORTED_BY_CALLBACK (11)
A multi handle callback returned error.
CURLM_UNRECOVERABLE_POLL (12)
An internal call to poll() or select() returned error that is not recoverable.
Curlshcode
The “share” interface will return a CURLSHcode to indicate when an error has occurred. Also consider curl_share_strerror.
CURLSHE_OK (0)
All fine. Proceed as usual.
CURLSHE_BAD_OPTION (1)
An invalid option was passed to the function.
CURLSHE_IN_USE (2)
The share object is currently in use.
CURLSHE_INVALID (3)
An invalid share object was passed to the function.
CURLSHE_NOMEM (4)
Not enough memory was available. (Added in 7.12.0)
CURLSHE_NOT_BUILT_IN (5)
The requested sharing could not be done because the library you use do not have that particular feature enabled. (Added in 7.23.0)
Curlucode
The URL interface will return a CURLUcode to indicate when an error has occurred. Also consider curl_url_strerror.
CURLUE_BAD_HANDLE (1)
An invalid URL handle was passed as argument.
CURLUE_BAD_PARTPOINTER (2)
An invalid ‘part’ argument was passed as argument.
CURLUE_MALFORMED_INPUT (3)
A malformed input was passed to a URL API function.
CURLUE_BAD_PORT_NUMBER (4)
The port number was not a decimal number between 0 and 65535.
CURLUE_UNSUPPORTED_SCHEME (5)
This libcurl build does not support the given URL scheme.
CURLUE_URLDECODE (6)
URL decode error, most likely because of rubbish in the input.
CURLUE_OUT_OF_MEMORY (7)
A memory function failed.
CURLUE_USER_NOT_ALLOWED (8)
Credentials was passed in the URL when prohibited.
CURLUE_UNKNOWN_PART (9)
An unknown part ID was passed to a URL API function.
CURLUE_NO_SCHEME (10)
There is no scheme part in the URL.
CURLUE_NO_USER (11)
There is no user part in the URL.
CURLUE_NO_PASSWORD (12)
There is no password part in the URL.
CURLUE_NO_OPTIONS (13)
There is no options part in the URL.
CURLUE_NO_HOST (14)
There is no host part in the URL.
CURLUE_NO_PORT (15)
There is no port part in the URL.
CURLUE_NO_QUERY (16)
There is no query part in the URL.
CURLUE_NO_FRAGMENT (17)
There is no fragment part in the URL.
CURLUE_NO_ZONEID (18)
There is no zone id set in the URL.
CURLUE_BAD_FILE_URL (19)
The file:// URL is invalid.
CURLUE_BAD_FRAGMENT (20)
The fragment part of the URL contained bad or invalid characters.
CURLUE_BAD_HOSTNAME (21)
The hostname contained bad or invalid characters.
CURLUE_BAD_IPV6 (22)
The IPv6 address hostname contained bad or invalid characters.
CURLUE_BAD_LOGIN (23)
The login part of the URL contained bad or invalid characters.
CURLUE_BAD_PASSWORD (24)
The password part of the URL contained bad or invalid characters.
CURLUE_BAD_PATH (25)
The path part of the URL contained bad or invalid characters.
CURLUE_BAD_QUERY (26)
The query part of the URL contained bad or invalid characters.
CURLUE_BAD_SCHEME (27)
The scheme part of the URL contained bad or invalid characters.
CURLUE_BAD_SLASHES (28)
The URL contained an invalid number of slashes.
CURLUE_BAD_USER (29)
The user part of the URL contained bad or invalid characters.
See also
curl_easy_strerror(3), curl_multi_strerror(3), curl_share_strerror(3), curl_url_strerror(3), CURLOPT_ERRORBUFFER(3), CURLOPT_VERBOSE(3), CURLOPT_DEBUGFUNCTION(3)
