PHP Manual
cURL
Predefined Constants

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Descriptions and uses for these constants are described within the curl_setopt(), curl_multi_setopt() and curl_getinfo() documentation.

CURLOPT_AUTOREFERER (int)
CURLOPT_COOKIESESSION (int)
CURLOPT_DOH_URL (int): Provides the DNS-over-HTTPS URL. Available as of PHP 8.1.0 and cURL 7.62.0.
CURLOPT_DNS_USE_GLOBAL_CACHE (int)
CURLOPT_DNS_CACHE_TIMEOUT (int)
CURLOPT_FTP_SSL (int)
CURLFTP_CREATE_DIR (int): Available since PHP 7.0.7 and cURL 7.19.3
CURLFTP_CREATE_DIR_NONE (int): Available since PHP 7.0.7 and cURL 7.19.3
CURLFTP_CREATE_DIR_RETRY (int): Available since PHP 7.0.7 and cURL 7.19.3
CURLFTPSSL_TRY (int)
CURLFTPSSL_ALL (int)
CURLFTPSSL_CONTROL (int)
CURLFTPSSL_NONE (int)
CURLOPT_PRIVATE (int)
CURLOPT_FTPSSLAUTH (int)
CURLOPT_PORT (int)
CURLOPT_FILE (int)
CURLOPT_INFILE (int)
CURLOPT_INFILESIZE (int)
CURLOPT_ISSUERCERT_BLOB (int): Issuer SSL certificate from memory blob. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_URL (int)
CURLOPT_PROXY (int)
CURLOPT_PROXY_ISSUERCERT (int): Proxy issuer SSL certificate filename. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_PROXY_ISSUERCERT_BLOB (int): Proxy issuer SSL certificate from memory blob. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_PROXY_SSLCERT_BLOB (int): SSL proxy client certificate from memory blob. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_PROXY_SSLKEY_BLOB (int): Private key for proxy cert from memory blob. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_VERBOSE (int)
CURLOPT_HEADER (int)
CURLOPT_HTTPHEADER (int)
CURLOPT_NOPROGRESS (int)
CURLOPT_NOBODY (int)
CURLOPT_FAILONERROR (int)
CURLOPT_UPLOAD (int)
CURLOPT_POST (int)
CURLOPT_FTPLISTONLY (int)
CURLOPT_FTPAPPEND (int)
CURLOPT_FTP_CREATE_MISSING_DIRS (int)
CURLOPT_NETRC (int)
CURLOPT_FOLLOWLOCATION (int): This constant is not available when open_basedir is enabled.
CURLOPT_FTPASCII (int)
CURLOPT_PUT (int)
CURLOPT_MUTE (int)
CURLOPT_USERPWD (int)
CURLOPT_PROXYUSERPWD (int)
CURLOPT_RANGE (int)
CURLOPT_TIMEOUT (int)
CURLOPT_TIMEOUT_MS (int)
CURLOPT_TCP_NODELAY (int)
CURLOPT_POSTFIELDS (int)
CURLOPT_PROGRESSFUNCTION (int)
CURLOPT_REFERER (int)
CURLOPT_USERAGENT (int)
CURLOPT_FTPPORT (int)
CURLOPT_FTP_USE_EPSV (int)
CURLOPT_LOW_SPEED_LIMIT (int)
CURLOPT_LOW_SPEED_TIME (int)
CURLOPT_RESUME_FROM (int)
CURLOPT_COOKIE (int)
CURLOPT_COOKIELIST (int): Available since cURL 7.14.1
CURLOPT_SSLCERT (int)
CURLOPT_SSLCERT_BLOB (int): SSL client certificate from memory blob. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_SSLCERTPASSWD (int)
CURLOPT_SSLKEY_BLOB (int): Private key for client cert from memory blob. Available as of PHP 8.1.0 and cURL 7.71.0.
CURLOPT_WRITEHEADER (int)
CURLOPT_SSL_VERIFYHOST (int)
CURLOPT_COOKIEFILE (int)
CURLOPT_SSLVERSION (int)
CURL_SSLVERSION_DEFAULT (int)
CURL_SSLVERSION_TLSv1 (int)
CURL_SSLVERSION_SSLv2 (int)
CURL_SSLVERSION_SSLv3 (int)
CURL_SSLVERSION_TLSv1_0 (int)
CURL_SSLVERSION_TLSv1_1 (int)
CURL_SSLVERSION_TLSv1_2 (int)
CURLOPT_TIMECONDITION (int)
CURLOPT_TIMEVALUE (int)
CURLOPT_CUSTOMREQUEST (int)
CURLOPT_STDERR (int)
CURLOPT_TRANSFERTEXT (int)
CURLOPT_RETURNTRANSFER (int)
CURLOPT_QUOTE (int)
CURLOPT_POSTQUOTE (int)
CURLOPT_INTERFACE (int)
CURLOPT_KRB4LEVEL (int)
CURLOPT_HTTPPROXYTUNNEL (int)
CURLOPT_FILETIME (int)
CURLOPT_WRITEFUNCTION (int)
CURLOPT_READFUNCTION (int)
CURLOPT_PASSWDFUNCTION (int)
CURLOPT_HEADERFUNCTION (int)
CURLOPT_MAXREDIRS (int)
CURLOPT_MAXCONNECTS (int)
CURLOPT_FRESH_CONNECT (int)
CURLOPT_FORBID_REUSE (int)
CURLOPT_RANDOM_FILE (int)
CURLOPT_EGDSOCKET (int)
CURLOPT_CONNECTTIMEOUT (int)
CURLOPT_CONNECTTIMEOUT_MS (int)
CURLOPT_SSL_VERIFYPEER (int)
CURLOPT_CAINFO (int)
CURLOPT_CAPATH (int)
CURLOPT_COOKIEJAR (int)
CURLOPT_SSL_CIPHER_LIST (int)
CURLOPT_BINARYTRANSFER (int)
CURLOPT_NOSIGNAL (int)
CURLOPT_PROXYTYPE (int): Available as of cURL 7.10.
CURLOPT_BUFFERSIZE (int)
CURLOPT_HTTPGET (int)
CURLOPT_HTTP_VERSION (int)
CURLOPT_SSLKEY (int)
CURLOPT_SSLKEYTYPE (int)
CURLOPT_SSLKEYPASSWD (int)
CURLOPT_SSLENGINE (int)
CURLOPT_SSLENGINE_DEFAULT (int)
CURLOPT_SSLCERTTYPE (int)
CURLOPT_CRLF (int)
CURLOPT_ENCODING (int)
CURLOPT_PROXYPORT (int)
CURLOPT_UNRESTRICTED_AUTH (int)
CURLOPT_FTP_USE_EPRT (int)
CURLOPT_HTTP200ALIASES (int)
CURLOPT_HTTPAUTH (int)
CURLAUTH_BASIC (int)
CURLAUTH_DIGEST (int)
CURLAUTH_GSSNEGOTIATE (int)
CURLAUTH_NEGOTIATE (int): Available since PHP 7.0.7 and cURL 7.38.0.
CURLAUTH_NTLM (int)
CURLAUTH_NTLM_WB (int): Available since PHP 7.0.7 and cURL 7.22.0
CURLAUTH_ANY (int)
CURLAUTH_ANYSAFE (int)
CURLOPT_PROXYAUTH (int)
CURLOPT_MAX_RECV_SPEED_LARGE (int): Available since cURL 7.15.5
CURLOPT_MAX_SEND_SPEED_LARGE (int): Available since cURL 7.15.5
CURLOPT_HEADEROPT (int): Available since PHP 7.0.7 and cURL 7.37.0
CURLOPT_PROXYHEADER (int): Available since PHP 7.0.7 and cURL 7.37.0
CURLINFO_PRIVATE (int)
CURLINFO_EFFECTIVE_URL (int)
CURLINFO_HTTP_CODE (int): As of cURL 7.10.8, this is a legacy alias of CURLINFO_RESPONSE_CODE
CURLINFO_RESPONSE_CODE (int): Available since cURL 7.10.8
CURLINFO_HEADER_OUT (int)
CURLINFO_HEADER_SIZE (int)
CURLINFO_REQUEST_SIZE (int)
CURLINFO_TOTAL_TIME (int)
CURLINFO_NAMELOOKUP_TIME (int)
CURLINFO_CONNECT_TIME (int)
CURLINFO_PRETRANSFER_TIME (int)
CURLINFO_SIZE_UPLOAD (int)
CURLINFO_SIZE_DOWNLOAD (int)
CURLINFO_SPEED_DOWNLOAD (int)
CURLINFO_SPEED_UPLOAD (int)
CURLINFO_FILETIME (int)
CURLINFO_SSL_VERIFYRESULT (int)
CURLINFO_CONTENT_LENGTH_DOWNLOAD (int)
CURLINFO_CONTENT_LENGTH_UPLOAD (int)
CURLINFO_STARTTRANSFER_TIME (int)
CURLINFO_CONTENT_TYPE (int)
CURLINFO_REDIRECT_TIME (int)
CURLINFO_REDIRECT_COUNT (int)
CURLINFO_REDIRECT_URL (string)
CURLINFO_PRIMARY_IP (string)
CURLINFO_PRIMARY_PORT (int)
CURLINFO_LOCAL_IP (string)
CURLINFO_LOCAL_PORT (int)
CURL_PUSH_OK (int): Available since PHP 7.1.0 and cURL 7.44.0
CURL_PUSH_DENY (int): Available since PHP 7.1.0 and cURL 7.44.0
CURL_REDIR_POST_301 (int): Available since PHP 7.0.7 and cURL 7.18.2
CURL_REDIR_POST_302 (int): Available since PHP 7.0.7 and cURL 7.18.2
CURL_REDIR_POST_303 (int): Available since PHP 7.0.7 and cURL 7.25.1
CURL_REDIR_POST_ALL (int): Available since PHP 7.0.7 and cURL 7.18.2
CURL_TIMECOND_NONE (int)
CURL_TIMECOND_IFMODSINCE (int)
CURL_TIMECOND_IFUNMODSINCE (int)
CURL_TIMECOND_LASTMOD (int)
CURL_VERSION_ALTSVC (int): Available since PHP 7.3.6 and cURL 7.64.1
CURL_VERSION_ASYNCHDNS (int): Asynchronous DNS resolves. Available since PHP 7.3.0 and cURL 7.10.7
CURL_VERSION_BROTLI (int): Available since PHP 7.3.0 and cURL 7.57.0
CURL_VERSION_CONV (int): Character conversions supported. Available since PHP 7.3.0 and cURL 7.15.4
CURL_VERSION_CURLDEBUG (int): Debug memory tracking supported. Available since PHP 7.3.6 and cURL 7.19.6
CURL_VERSION_DEBUG (int): Built with debug capabilities. Available since PHP 7.3.0 and cURL 7.10.6
CURL_VERSION_GSSAPI (int): Built against a GSS-API library. Available since PHP 7.3.0 and cURL 7.38.0
CURL_VERSION_GSSNEGOTIATE (int): Negotiate auth is supported. Available since PHP 7.3.0 and cURL 7.10.6 (deprecated since 7.38.0)
CURL_VERSION_IDN (int): Internationized Domain Names are supported. Available since PHP 7.3.0 and cURL 7.12.0
CURL_VERSION_MULTI_SSL (int): Available since PHP 7.3.0 and cURL 7.56.0
CURL_VERSION_NTLM (int): NTLM auth is supported. Available since PHP 7.3.0 and cURL 7.10.6
CURL_VERSION_NTLM_WB (int): NTLM delegation to winbind helper is supported. Available since PHP 7.3.0 and cURL 7.22.0
CURL_VERSION_IPV6 (int): IPv6-enabled.
CURL_VERSION_KERBEROS4 (int): Kerberos V4 auth is supported.
CURL_VERSION_KERBEROS5 (int): Kerberos V5 auth is supported. Available since PHP 7.0.7 and cURL 7.40.0
CURL_VERSION_HTTP2 (int): HTTP2 support built-in. Available since cURL 7.33.0
CURL_VERSION_LARGEFILE (int): Supports files larger than 2GB. Available since cURL 7.33.0
CURL_VERSION_PSL (int): Mozilla's Public Suffix List, used for cookie domain verification. Available since PHP 7.3.6 and cURL 7.47.0
CURL_VERSION_SPNEGO (int): SPNEGO auth is supported. Available since PHP 7.3.0 and cURL 7.10.8
CURL_VERSION_SSPI (int): Built against Windows SSPI. Available since PHP 7.3.0 and cURL 7.13.2
CURL_VERSION_SSL (int): SSL options are present.
CURL_VERSION_TLSAUTH_SRP (int): TLS-SRP auth is supported. Available since PHP 7.3.0 and cURL 7.21.4
CURL_VERSION_UNIX_SOCKETS (int): Unix domain sockets support. Available since PHP 7.0.7 and cURL 7.40.0
CURL_VERSION_LIBZ (int): libz features are present.
CURLVERSION_NOW (int)
CURLE_OK (int)
CURLE_UNSUPPORTED_PROTOCOL (int)
CURLE_FAILED_INIT (int)
CURLE_URL_MALFORMAT (int)
CURLE_URL_MALFORMAT_USER (int)
CURLE_COULDNT_RESOLVE_PROXY (int)
CURLE_COULDNT_RESOLVE_HOST (int)
CURLE_COULDNT_CONNECT (int)
CURLE_FTP_WEIRD_SERVER_REPLY (int)
CURLE_FTP_ACCESS_DENIED (int)
CURLE_FTP_USER_PASSWORD_INCORRECT (int)
CURLE_FTP_WEIRD_PASS_REPLY (int)
CURLE_FTP_WEIRD_USER_REPLY (int)
CURLE_FTP_WEIRD_PASV_REPLY (int)
CURLE_FTP_WEIRD_227_FORMAT (int)
CURLE_FTP_CANT_GET_HOST (int)
CURLE_FTP_CANT_RECONNECT (int)
CURLE_FTP_COULDNT_SET_BINARY (int)
CURLE_PARTIAL_FILE (int)
CURLE_FTP_COULDNT_RETR_FILE (int)
CURLE_FTP_WRITE_ERROR (int)
CURLE_FTP_QUOTE_ERROR (int)
CURLE_HTTP_NOT_FOUND (int)
CURLE_WRITE_ERROR (int)
CURLE_MALFORMAT_USER (int)
CURLE_FTP_COULDNT_STOR_FILE (int)
CURLE_READ_ERROR (int)
CURLE_OUT_OF_MEMORY (int)
CURLE_OPERATION_TIMEOUTED (int)
CURLE_FTP_COULDNT_SET_ASCII (int)
CURLE_FTP_PORT_FAILED (int)
CURLE_FTP_COULDNT_USE_REST (int)
CURLE_FTP_COULDNT_GET_SIZE (int)
CURLE_HTTP_RANGE_ERROR (int)
CURLE_HTTP_POST_ERROR (int)
CURLE_SSL_CONNECT_ERROR (int)
CURLE_FTP_BAD_DOWNLOAD_RESUME (int)
CURLE_FILE_COULDNT_READ_FILE (int)
CURLE_LDAP_CANNOT_BIND (int)
CURLE_LDAP_SEARCH_FAILED (int)
CURLE_LIBRARY_NOT_FOUND (int)
CURLE_FUNCTION_NOT_FOUND (int)
CURLE_ABORTED_BY_CALLBACK (int)
CURLE_BAD_FUNCTION_ARGUMENT (int)
CURLE_BAD_CALLING_ORDER (int)
CURLE_HTTP_PORT_FAILED (int)
CURLE_BAD_PASSWORD_ENTERED (int)
CURLE_TOO_MANY_REDIRECTS (int)
CURLE_UNKNOWN_TELNET_OPTION (int)
CURLE_TELNET_OPTION_SYNTAX (int)
CURLE_OBSOLETE (int)
CURLE_SSL_PEER_CERTIFICATE (int)
CURLE_GOT_NOTHING (int)
CURLE_SSL_ENGINE_NOTFOUND (int)
CURLE_SSL_ENGINE_SETFAILED (int)
CURLE_SEND_ERROR (int)
CURLE_RECV_ERROR (int)
CURLE_SHARE_IN_USE (int)
CURLE_SSL_CERTPROBLEM (int)
CURLE_SSL_CIPHER (int)
CURLE_SSL_CACERT (int)
CURLE_BAD_CONTENT_ENCODING (int)
CURLE_LDAP_INVALID_URL (int)
CURLE_FILESIZE_EXCEEDED (int)
CURLE_FTP_SSL_FAILED (int)
CURLE_SSH (int): Available since cURL 7.16.1.
CURLFTPAUTH_DEFAULT (int)
CURLFTPAUTH_SSL (int)
CURLFTPAUTH_TLS (int)
CURLPROXY_HTTP (int): Available since cURL 7.10.
CURLPROXY_HTTP_1_0 (int): Available since PHP 7.0.7 and cURL 7.19.3
CURLPROXY_SOCKS4 (int): Available since cURL 7.10.
CURLPROXY_SOCKS5 (int): Available since cURL 7.10.
CURL_NETRC_OPTIONAL (int)
CURL_NETRC_IGNORED (int)
CURL_NETRC_REQUIRED (int)
CURL_HTTP_VERSION_NONE (int)
CURL_HTTP_VERSION_1_0 (int)
CURL_HTTP_VERSION_1_1 (int)
CURL_HTTP_VERSION_2 (int): Available since PHP 7.0.7 and cURL 7.43.0
CURL_HTTP_VERSION_2_0 (int): Available since cURL 7.33.0
CURL_HTTP_VERSION_2TLS (int): Available since PHP 7.0.7 and cURL 7.47.0
CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE (int): Available since PHP 7.0.7 and cURL 7.49.0
CURLM_CALL_MULTI_PERFORM (int)
CURLM_OK (int)
CURLM_BAD_HANDLE (int)
CURLM_BAD_EASY_HANDLE (int)
CURLM_OUT_OF_MEMORY (int)
CURLM_INTERNAL_ERROR (int)
CURLMSG_DONE (int)
CURLOPT_KEYPASSWD (int)
CURLOPT_SSH_AUTH_TYPES (int)
CURLOPT_SSH_HOST_PUBLIC_KEY_MD5 (int)
CURLOPT_SSH_PRIVATE_KEYFILE (int)
CURLOPT_SSH_PUBLIC_KEYFILE (int)
CURLOPT_SSL_OPTIONS (int): Available since cURL 7.25.0
CURLSSLOPT_ALLOW_BEAST (int): Available since cURL 7.25.0
CURLSSLOPT_NO_REVOKE (int): Available since PHP 7.0.7 and cURL 7.44.0
CURLOPT_USERNAME (int): Available since cURL 7.19.1
CURLOPT_SASL_IR (int): Available since PHP 7.0.7 and cURL 7.31.0
CURLOPT_DNS_INTERFACE (int): Available since PHP 7.0.7 and cURL 7.33.0
CURLOPT_DNS_LOCAL_IP4 (int): Available since PHP 7.0.7 and cURL 7.33.0
CURLOPT_DNS_LOCAL_IP6 (int): Available since PHP 7.0.7 and cURL 7.33.0
CURLOPT_XOAUTH2_BEARER (int): Available since PHP 7.0.7 and cURL 7.33.0
CURLOPT_LOGIN_OPTIONS (int): Available since PHP 7.0.7 and cURL 7.34.0
CURLOPT_EXPECT_100_TIMEOUT_MS (int): Available since PHP 7.0.7 and cURL 7.36.0
CURLOPT_SSL_ENABLE_ALPN (int): Available since PHP 7.0.7 and cURL 7.36.0
CURLOPT_SSL_ENABLE_NPN (int): Available since PHP 7.0.7 and cURL 7.36.0
CURLOPT_PINNEDPUBLICKEY (int): Available since PHP 7.0.7 and cURL 7.39.0
CURLOPT_UNIX_SOCKET_PATH (int): Available since PHP 7.0.7 and cURL 7.40.0
CURLOPT_SSL_VERIFYSTATUS (int): Available since PHP 7.0.7 and cURL 7.41.0
CURLOPT_PATH_AS_IS (int): Available since PHP 7.0.7 and cURL 7.42.0
CURLOPT_SSL_FALSESTART (int): Available since PHP 7.0.7 and cURL 7.42.0
CURLOPT_PIPEWAIT (int): Available since PHP 7.0.7 and cURL 7.43.0
CURLOPT_PROXY_SERVICE_NAME (int): Available since PHP 7.0.7 and cURL 7.43.0
CURLOPT_SERVICE_NAME (int): Available since PHP 7.0.7 and cURL 7.43.0
CURLOPT_DEFAULT_PROTOCOL (int): Available since PHP 7.0.7 and cURL 7.45.0
CURLOPT_STREAM_WEIGHT (int): Available since PHP 7.0.7 and cURL 7.46.0
CURLOPT_TFTP_NO_OPTIONS (int): Available since PHP 7.0.7 and cURL 7.48.0
CURLOPT_CONNECT_TO (int): Available since PHP 7.0.7 and cURL 7.49.0
CURLOPT_TCP_FASTOPEN (int): Available since PHP 7.0.7 and cURL 7.49.0
CURLOPT_TCP_KEEPALIVE (int): Available since cURL 7.25.0
CURLOPT_TCP_KEEPIDLE (int): Available since cURL 7.25.0
CURLOPT_TCP_KEEPINTVL (int): Available since cURL 7.25.0
CURLMOPT_PIPELINING (int): Available since cURL 7.16.0.
CURLMOPT_MAXCONNECTS (int): Available since cURL 7.16.3.
CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE (int): Available since PHP 7.0.7 and cURL 7.30.0
CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE (int): Available since PHP 7.0.7 and cURL 7.30.0
CURLMOPT_MAX_HOST_CONNECTIONS (int): Available since PHP 7.0.7 and cURL 7.30.0
CURLMOPT_MAX_PIPELINE_LENGTH (int): Available since PHP 7.0.7 and cURL 7.30.0
CURLMOPT_MAX_TOTAL_CONNECTIONS (int): Available since PHP 7.0.7 and cURL 7.30.0
CURLMOPT_PUSHFUNCTION (int): Available since PHP 7.1.0 and cURL 7.44.0
CURLSSH_AUTH_AGENT (int): Available since PHP 7.0.7 and cURL 7.28.0
CURLSSH_AUTH_ANY (int)
CURLSSH_AUTH_DEFAULT (int)
CURLSSH_AUTH_HOST (int)
CURLSSH_AUTH_KEYBOARD (int)
CURLSSH_AUTH_NONE (int)
CURLSSH_AUTH_PASSWORD (int)
CURLSSH_AUTH_PUBLICKEY (int)
CURLPAUSE_ALL (int): Available since cURL 7.18.0.
CURLPAUSE_CONT (int): Available since cURL 7.18.0.
CURLPAUSE_RECV (int): Available since cURL 7.18.0.
CURLPAUSE_RECV_CONT (int): Available since cURL 7.18.0.
CURLPAUSE_SEND (int): Available since cURL 7.18.0.
CURLPAUSE_SEND_CONT (int): Available since cURL 7.18.0.
CURLPIPE_NOTHING (int): Available since cURL 7.43.0.
CURLPIPE_HTTP1 (int): Available since cURL 7.43.0.
CURLPIPE_MULTIPLEX (int): Available since cURL 7.43.0.
CURLPROXY_SOCKS4A (int): Available since cURL 7.18.0.
CURLPROXY_SOCKS5_HOSTNAME (int): Available since cURL 7.18.0.
CURLHEADER_SEPARATE (int): Available since PHP 7.0.7 and cURL 7.37.0.
CURLHEADER_UNIFIED (int): Available since PHP 7.0.7 and cURL 7.37.0.
CURLPROTO_SMB (int): Available since PHP 7.0.7 and cURL 7.40.0.
CURLPROTO_SMBS (int): Available since PHP 7.0.7 and cURL 7.40.0.
CURLOPT_REQUEST_TARGET (int): Available since PHP 7.3.0 and cURL 7.55.0.
CURLAUTH_GSSAPI (int): Available since PHP 7.3.0 and cURL 7.54.1
CURLE_WEIRD_SERVER_REPLY (int): Available since PHP 7.3.0 and cURL 7.51.0
CURLINFO_CONTENT_LENGTH_DOWNLOAD_T (int): Available since PHP 7.3.0 and cURL 7.55.0
CURLINFO_CONTENT_LENGTH_UPLOAD_T (int): Available since PHP 7.3.0 and cURL 7.55.0
CURLINFO_HTTP_VERSION (int): Available since PHP 7.3.0 and cURL 7.50.0
CURLINFO_PROTOCOL (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLINFO_PROXY_SSL_VERIFYRESULT (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLINFO_SCHEME (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLINFO_SIZE_DOWNLOAD_T (int): Available since PHP 7.3.0 and cURL 7.50.0
CURLINFO_SIZE_UPLOAD_T (int): Available since PHP 7.3.0 and cURL 7.50.0
CURLINFO_SPEED_DOWNLOAD_T (int): Available since PHP 7.3.0 and cURL 7.50.0
CURLINFO_SPEED_UPLOAD_T (int): Available since PHP 7.3.0 and cURL 7.50.0
CURL_MAX_READ_SIZE (int): Available since PHP 7.3.0 and cURL 7.53.0
CURLOPT_ABSTRACT_UNIX_SOCKET (int): Available since PHP 7.3.0 and cURL 7.53.0
CURLOPT_KEEP_SENDING_ON_ERROR (int): Available since PHP 7.3.0 and cURL 7.51.0
CURLOPT_PRE_PROXY (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_CAINFO (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_CAPATH (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_CRLFILE (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_KEYPASSWD (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_PINNEDPUBLICKEY (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSLCERT (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSLCERTTYPE (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSL_CIPHER_LIST (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSLKEY (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSLKEYTYPE (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSL_OPTIONS (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSL_VERIFYHOST (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSL_VERIFYPEER (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_SSLVERSION (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_TLSAUTH_PASSWORD (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_TLSAUTH_TYPE (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_PROXY_TLSAUTH_USERNAME (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLOPT_SOCKS5_AUTH (int): Available since PHP 7.3.0 and cURL 7.55.0
CURLOPT_SUPPRESS_CONNECT_HEADERS (int): Available since PHP 7.3.0 and cURL 7.54.0
CURLPROXY_HTTPS (int): Available since PHP 7.3.0 and cURL 7.52.0
CURL_SSLVERSION_MAX_DEFAULT (int): Available since PHP 7.3.0 and cURL 7.54.0
CURL_SSLVERSION_MAX_NONE (int): Available since PHP 7.3.0 and cURL 7.54.0
CURL_SSLVERSION_MAX_TLSv1_0 (int): Available since PHP 7.3.0 and cURL 7.54.0
CURL_SSLVERSION_MAX_TLSv1_1 (int): Available since PHP 7.3.0 and cURL 7.54.0
CURL_SSLVERSION_MAX_TLSv1_2 (int): Available since PHP 7.3.0 and cURL 7.54.0
CURL_SSLVERSION_MAX_TLSv1_3 (int): Available since PHP 7.3.0 and cURL 7.54.0
CURL_SSLVERSION_TLSv1_3 (int): Available since PHP 7.3.0 and cURL 7.52.0
CURL_VERSION_HTTPS_PROXY (int): Available since PHP 7.3.0 and cURL 7.52.0
CURLAUTH_BEARER (int): Available since PHP 7.3.0 and cURL 7.61.0.
CURLINFO_APPCONNECT_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLINFO_CONNECT_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLINFO_FILETIME_T (int): Available since PHP 7.3.0 and cURL 7.59.0
CURLINFO_NAMELOOKUP_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLINFO_PRETRANSFER_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLINFO_REDIRECT_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLINFO_STARTTRANSFER_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLINFO_TOTAL_TIME_T (int): Available since PHP 7.3.0 and cURL 7.61.0
CURL_LOCK_DATA_CONNECT (int): Available since PHP 7.3.0 and cURL 7.10.0
CURL_LOCK_DATA_PSL (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLOPT_DISALLOW_USERNAME_IN_URL (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLOPT_DNS_SHUFFLE_ADDRESSES (int): Available since PHP 7.3.0 and cURL 7.60.0
CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS (int): Available since PHP 7.3.0 and cURL 7.59.0
CURLOPT_HAPROXYPROTOCOL (int): Available since PHP 7.3.0 and cURL 7.60.0
CURLOPT_PROXY_TLS13_CIPHERS (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLOPT_SSH_COMPRESSION (int): Available since PHP 7.3.0 and cURL 7.56.0
CURLOPT_TIMEVALUE_LARGE (int): Available since PHP 7.3.0 and cURL 7.59.0
CURLOPT_TLS13_CIPHERS (int): Available since PHP 7.3.0 and cURL 7.61.0
CURLSSH_AUTH_GSSAPI (int): Available since PHP 7.3.0 and cURL 7.58.0
CURLOPT_HTTP09_ALLOWED (int): Available since PHP 7.3.15 and 7.4.3, respectively, and cURL 7.64.0