This is a table of available options for curl_easy_setopt().
| Option | Purpose |
|---|---|
CURLOPT_ABSTRACT_UNIX_SOCKET |
abstract Unix domain socket |
CURLOPT_ACCEPT_ENCODING |
automatic decompression of HTTP downloads |
CURLOPT_ACCEPTTIMEOUT_MS |
timeout waiting for FTP server to connect back |
CURLOPT_ADDRESS_SCOPE |
scope id for IPv6 addresses |
CURLOPT_ALTSVC_CTRL |
control alt-svc behavior |
CURLOPT_ALTSVC |
alt-svc cache filename |
CURLOPT_APPEND |
append to the remote file |
CURLOPT_AUTOREFERER |
automatically update the referer header |
CURLOPT_AWS_SIGV4 |
V4 signature |
CURLOPT_BUFFERSIZE |
receive buffer size |
CURLOPT_CA_CACHE_TIMEOUT |
life-time for cached certificate stores |
CURLOPT_CAINFO_BLOB |
Certificate Authority (CA) bundle in PEM format |
CURLOPT_CAINFO |
path to Certificate Authority (CA) bundle |
CURLOPT_CAPATH |
directory holding CA certificates |
CURLOPT_CERTINFO |
request SSL certificate information |
CURLOPT_CHUNK_BGN_FUNCTION |
callback before a transfer with FTP wildcardmatch |
CURLOPT_CHUNK_DATA |
pointer passed to the FTP chunk callbacks |
CURLOPT_CHUNK_END_FUNCTION |
callback after a transfer with FTP wildcardmatch |
CURLOPT_CLOSESOCKETDATA |
pointer passed to the socket close callback |
CURLOPT_CLOSESOCKETFUNCTION |
callback to socket close replacement |
CURLOPT_CONNECT_ONLY |
stop when connected to target server |
CURLOPT_CONNECT_TO |
connect to a specific host and port instead of the URL's host and port |
CURLOPT_CONNECTTIMEOUT_MS |
timeout for the connect phase |
CURLOPT_CONNECTTIMEOUT |
timeout for the connect phase |
CURLOPT_CONV_FROM_NETWORK_FUNCTION |
convert data from network to host encoding |
CURLOPT_CONV_FROM_UTF8_FUNCTION |
convert data from UTF8 to host encoding |
CURLOPT_CONV_TO_NETWORK_FUNCTION |
convert data to network from host encoding |
CURLOPT_COOKIE |
HTTP Cookie header |
CURLOPT_COOKIEFILE |
filename to read cookies from |
CURLOPT_COOKIEJAR |
filename to store cookies to |
CURLOPT_COOKIELIST |
add to or manipulate cookies held in memory |
CURLOPT_COOKIESESSION |
start a new cookie session |
CURLOPT_COPYPOSTFIELDS |
have libcurl copy data to POST |
CURLOPT_CRLF |
CRLF conversion |
CURLOPT_CRLFILE |
Certificate Revocation List file |
CURLOPT_CURLU |
URL in CURLU * format |
CURLOPT_CUSTOMREQUEST |
custom request method |
CURLOPT_DEBUGDATA |
pointer passed to the debug callback |
CURLOPT_DEBUGFUNCTION |
debug callback |
CURLOPT_DEFAULT_PROTOCOL |
default protocol to use if the URL is missing a |
CURLOPT_DIRLISTONLY |
ask for names only in a directory listing |
CURLOPT_DISALLOW_USERNAME_IN_URL |
disallow specifying username in the URL |
CURLOPT_DNS_CACHE_TIMEOUT |
life-time for DNS cache entries |
CURLOPT_DNS_INTERFACE |
interface to speak DNS over |
CURLOPT_DNS_LOCAL_IP4 |
IPv4 address to bind DNS resolves to |
CURLOPT_DNS_LOCAL_IP6 |
IPv6 address to bind DNS resolves to |
CURLOPT_DNS_SERVERS |
DNS servers to use |
CURLOPT_DNS_SHUFFLE_ADDRESSES |
shuffle IP addresses for hostname |
CURLOPT_DNS_USE_GLOBAL_CACHE |
global DNS cache |
CURLOPT_DOH_SSL_VERIFYHOST |
verify the hostname in the DoH SSL certificate |
CURLOPT_DOH_SSL_VERIFYPEER |
verify the DoH SSL certificate |
CURLOPT_DOH_SSL_VERIFYSTATUS |
verify the DoH SSL certificate's status |
CURLOPT_DOH_URL |
provide the DNS-over-HTTPS URL |
CURLOPT_EGDSOCKET |
EGD socket path |
CURLOPT_ERRORBUFFER |
error buffer for error messages |
CURLOPT_EXPECT_100_TIMEOUT_MS |
timeout for Expect: 100-continue response |
CURLOPT_FAILONERROR |
request failure on HTTP response >= 400 |
CURLOPT_FILETIME |
get the modification time of the remote resource |
CURLOPT_FNMATCH_DATA |
pointer passed to the fnmatch callback |
CURLOPT_FNMATCH_FUNCTION |
wildcard match callback |
CURLOPT_FOLLOWLOCATION |
follow HTTP 3xx redirects |
CURLOPT_FORBID_REUSE |
make connection get closed at once after use |
CURLOPT_FRESH_CONNECT |
force a new connection to be used |
CURLOPT_FTP_ACCOUNT |
account info for FTP |
CURLOPT_FTP_ALTERNATIVE_TO_USER |
command to use instead of USER with FTP |
CURLOPT_FTP_CREATE_MISSING_DIRS |
create missing dirs for FTP and SFTP |
CURLOPT_FTP_FILEMETHOD |
select directory traversing method for FTP |
CURLOPT_FTP_RESPONSE_TIMEOUT |
time allowed to wait for FTP response |
CURLOPT_FTP_SKIP_PASV_IP |
ignore the IP address in the PASV response |
CURLOPT_FTP_SSL_CCC |
switch off SSL again with FTP after auth |
CURLOPT_FTP_USE_EPRT |
use EPRT for FTP |
CURLOPT_FTP_USE_EPSV |
use EPSV for FTP |
CURLOPT_FTP_USE_PRET |
use PRET for FTP |
CURLOPT_FTPPORT |
make FTP transfer active |
CURLOPT_FTPSSLAUTH |
order in which to attempt TLS vs SSL |
CURLOPT_GSSAPI_DELEGATION |
allowed GSS-API delegation |
CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS |
head start for ipv6 for happy eyeballs |
CURLOPT_HAPROXY_CLIENT_IP |
set HAProxy PROXY protocol client IP |
CURLOPT_HAPROXYPROTOCOL |
send HAProxy PROXY protocol v1 header |
CURLOPT_HEADER |
pass headers to the data stream |
CURLOPT_HEADERDATA |
pointer to pass to header callback |
CURLOPT_HEADERFUNCTION |
callback that receives header data |
CURLOPT_HEADEROPT |
send HTTP headers to both proxy and host or separately |
CURLOPT_HSTS_CTRL |
control HSTS behavior |
CURLOPT_HSTS |
HSTS cache filename |
CURLOPT_HSTSREADDATA |
pointer passed to the HSTS read callback |
CURLOPT_HSTSREADFUNCTION |
read callback for HSTS hosts |
CURLOPT_HSTSWRITEDATA |
pointer passed to the HSTS write callback |
CURLOPT_HSTSWRITEFUNCTION |
write callback for HSTS hosts |
CURLOPT_HTTP09_ALLOWED |
allow HTTP/0.9 response |
CURLOPT_HTTP200ALIASES |
alternative matches for HTTP 200 OK |
CURLOPT_HTTP_CONTENT_DECODING |
HTTP content decoding control |
CURLOPT_HTTP_TRANSFER_DECODING |
HTTP transfer decoding control |
CURLOPT_HTTP_VERSION |
HTTP protocol version to use |
CURLOPT_HTTPAUTH |
HTTP server authentication methods to try |
CURLOPT_HTTPGET |
ask for an HTTP GET request |
CURLOPT_HTTPHEADER |
set of HTTP headers |
CURLOPT_HTTPPOST |
multipart formpost content |
CURLOPT_HTTPPROXYTUNNEL |
tunnel through HTTP proxy |
CURLOPT_IGNORE_CONTENT_LENGTH |
ignore content length |
CURLOPT_INFILESIZE_LARGE |
size of the input file to send off |
CURLOPT_INFILESIZE |
size of the input file to send off |
CURLOPT_INTERFACE |
source interface for outgoing traffic |
CURLOPT_INTERLEAVEDATA |
pointer passed to RTSP interleave callback |
CURLOPT_INTERLEAVEFUNCTION |
callback for RTSP interleaved data |
CURLOPT_IOCTLDATA |
pointer passed to I/O callback |
CURLOPT_IOCTLFUNCTION |
callback for I/O operations |
CURLOPT_IPRESOLVE |
IP protocol version to use |
CURLOPT_ISSUERCERT_BLOB |
issuer SSL certificate from memory blob |
CURLOPT_ISSUERCERT |
issuer SSL certificate filename |
CURLOPT_KEEP_SENDING_ON_ERROR |
keep sending on early HTTP response >= 300 |
CURLOPT_KEYPASSWD |
passphrase to private key |
CURLOPT_KRBLEVEL |
FTP kerberos security level |
CURLOPT_LOCALPORT |
local port number to use for socket |
CURLOPT_LOCALPORTRANGE |
number of additional local ports to try |
CURLOPT_LOGIN_OPTIONS |
login options |
CURLOPT_LOW_SPEED_LIMIT |
low speed limit in bytes per second |
CURLOPT_LOW_SPEED_TIME |
low speed limit time period |
CURLOPT_MAIL_AUTH |
SMTP authentication address |
CURLOPT_MAIL_FROM |
SMTP sender address |
CURLOPT_MAIL_RCPT_ALLOWFAILS |
allow RCPT TO command to fail for some recipients |
CURLOPT_MAIL_RCPT |
list of SMTP mail recipients |
CURLOPT_MAX_RECV_SPEED_LARGE |
rate limit data download speed |
CURLOPT_MAX_SEND_SPEED_LARGE |
rate limit data upload speed |
CURLOPT_MAXAGE_CONN |
max idle time allowed for reusing a connection |
CURLOPT_MAXCONNECTS |
maximum connection cache size |
CURLOPT_MAXFILESIZE_LARGE |
maximum file size allowed to download |
CURLOPT_MAXFILESIZE |
maximum file size allowed to download |
CURLOPT_MAXLIFETIME_CONN |
max lifetime (since creation) allowed for reusing a connection |
CURLOPT_MAXREDIRS |
maximum number of redirects allowed |
CURLOPT_MIME_OPTIONS |
set MIME option flags |
CURLOPT_MIMEPOST |
send data from mime structure |
CURLOPT_NETRC_FILE |
filename to read .netrc info from |
CURLOPT_NETRC |
enable use of .netrc |
CURLOPT_NEW_DIRECTORY_PERMS |
permissions for remotely created directories |
CURLOPT_NEW_FILE_PERMS |
permissions for remotely created files |
CURLOPT_NOBODY |
do the download request without getting the body |
CURLOPT_NOPROGRESS |
switch off the progress meter |
CURLOPT_NOPROXY |
disable proxy use for specific hosts |
CURLOPT_NOSIGNAL |
skip all signal handling |
CURLOPT_OPENSOCKETDATA |
pointer passed to open socket callback |
CURLOPT_OPENSOCKETFUNCTION |
callback for opening socket |
CURLOPT_PASSWORD |
password to use in authentication |
CURLOPT_PATH_AS_IS |
do not handle dot dot sequences |
CURLOPT_PINNEDPUBLICKEY |
pinned public key |
CURLOPT_PIPEWAIT |
wait for pipelining/multiplexing |
CURLOPT_PORT |
remote port number to connect to |
CURLOPT_POST |
make an HTTP POST |
CURLOPT_POSTFIELDS |
data to POST to server |
CURLOPT_POSTFIELDSIZE_LARGE |
size of POST data pointed to |
CURLOPT_POSTFIELDSIZE |
size of POST data pointed to |
CURLOPT_POSTQUOTE |
(S)FTP commands to run after the transfer |
CURLOPT_POSTREDIR |
how to act on an HTTP POST redirect |
CURLOPT_PRE_PROXY |
pre-proxy host to use |
CURLOPT_PREQUOTE |
commands to run before an FTP transfer |
CURLOPT_PREREQDATA |
pointer passed to the pre-request callback |
CURLOPT_PREREQFUNCTION |
user callback called when a connection has been |
CURLOPT_PRIVATE |
store a private pointer |
CURLOPT_PROGRESSDATA |
pointer passed to the progress callback |
CURLOPT_PROGRESSFUNCTION |
progress meter callback |
CURLOPT_PROTOCOLS_STR |
allowed protocols |
CURLOPT_PROTOCOLS |
allowed protocols |
CURLOPT_PROXY_CAINFO_BLOB |
proxy Certificate Authority (CA) bundle in PEM format |
CURLOPT_PROXY_CAINFO |
path to proxy Certificate Authority (CA) bundle |
CURLOPT_PROXY_CAPATH |
directory holding HTTPS proxy CA certificates |
CURLOPT_PROXY_CRLFILE |
HTTPS proxy Certificate Revocation List file |
CURLOPT_PROXY_ISSUERCERT_BLOB |
proxy issuer SSL certificate from memory blob |
CURLOPT_PROXY_ISSUERCERT |
proxy issuer SSL certificate filename |
CURLOPT_PROXY_KEYPASSWD |
passphrase for the proxy private key |
CURLOPT_PROXY_PINNEDPUBLICKEY |
pinned public key for https proxy |
CURLOPT_PROXY_SERVICE_NAME |
proxy authentication service name |
CURLOPT_PROXY_SSL_CIPHER_LIST |
ciphers to use for HTTPS proxy |
CURLOPT_PROXY_SSL_OPTIONS |
HTTPS proxy SSL behavior options |
CURLOPT_PROXY_SSL_VERIFYHOST |
verify the proxy certificate's name against host |
CURLOPT_PROXY_SSL_VERIFYPEER |
verify the proxy's SSL certificate |
CURLOPT_PROXY_SSLCERT_BLOB |
SSL proxy client certificate from memory blob |
CURLOPT_PROXY_SSLCERT |
HTTPS proxy client certificate |
CURLOPT_PROXY_SSLCERTTYPE |
type of the proxy client SSL certificate |
CURLOPT_PROXY_SSLKEY_BLOB |
private key for proxy cert from memory blob |
CURLOPT_PROXY_SSLKEY |
private keyfile for HTTPS proxy client cert |
CURLOPT_PROXY_SSLKEYTYPE |
type of the proxy private key file |
CURLOPT_PROXY_SSLVERSION |
preferred HTTPS proxy TLS version |
CURLOPT_PROXY_TLS13_CIPHERS |
ciphers suites for proxy TLS 1.3 |
CURLOPT_PROXY_TLSAUTH_PASSWORD |
password to use for proxy TLS authentication |
CURLOPT_PROXY_TLSAUTH_TYPE |
HTTPS proxy TLS authentication methods |
CURLOPT_PROXY_TLSAUTH_USERNAME |
username to use for proxy TLS authentication |
CURLOPT_PROXY_TRANSFER_MODE |
append FTP transfer mode to URL for proxy |
CURLOPT_PROXY |
proxy to use |
CURLOPT_PROXYAUTH |
HTTP proxy authentication methods |
CURLOPT_PROXYHEADER |
set of HTTP headers to pass to proxy |
CURLOPT_PROXYPASSWORD |
password to use with proxy authentication |
CURLOPT_PROXYPORT |
port number the proxy listens on |
CURLOPT_PROXYTYPE |
proxy protocol type |
CURLOPT_PROXYUSERNAME |
username to use for proxy authentication |
CURLOPT_PROXYUSERPWD |
username and password to use for proxy authentication |
CURLOPT_PUT |
make an HTTP PUT request |
CURLOPT_QUICK_EXIT |
allow to exit quickly |
CURLOPT_QUOTE |
(S)FTP commands to run before transfer |
CURLOPT_RANDOM_FILE |
file to read random data from |
CURLOPT_RANGE |
byte range to request |
CURLOPT_READDATA |
pointer passed to the read callback |
CURLOPT_READFUNCTION |
read callback for data uploads |
CURLOPT_REDIR_PROTOCOLS_STR |
protocols allowed to redirect to |
CURLOPT_REDIR_PROTOCOLS |
protocols allowed to redirect to |
CURLOPT_REFERER |
the HTTP referer header |
CURLOPT_REQUEST_TARGET |
alternative target for this request |
CURLOPT_RESOLVE |
provide custom hostname to IP address resolves |
CURLOPT_RESOLVER_START_DATA |
pointer passed to the resolver start callback |
CURLOPT_RESOLVER_START_FUNCTION |
callback called before a new name resolve is started |
CURLOPT_RESUME_FROM_LARGE |
offset to resume transfer from |
CURLOPT_RESUME_FROM |
offset to resume transfer from |
CURLOPT_RTSP_CLIENT_CSEQ |
RTSP client CSEQ number |
CURLOPT_RTSP_REQUEST |
RTSP request |
CURLOPT_RTSP_SERVER_CSEQ |
RTSP server CSEQ number |
CURLOPT_RTSP_SESSION_ID |
RTSP session ID |
CURLOPT_RTSP_STREAM_URI |
RTSP stream URI |
CURLOPT_RTSP_TRANSPORT |
RTSP Transport: header |
CURLOPT_SASL_AUTHZID |
authorization identity (identity to act as) |
CURLOPT_SASL_IR |
send initial response in first packet |
CURLOPT_SEEKDATA |
pointer passed to the seek callback |
CURLOPT_SEEKFUNCTION |
user callback for seeking in input stream |
CURLOPT_SERVER_RESPONSE_TIMEOUT |
time in seconds allowed to wait for server response |
CURLOPT_SERVER_RESPONSE_TIMEOUT_MS |
time in milliseconds allowed to wait for server response |
CURLOPT_SERVICE_NAME |
authentication service name |
CURLOPT_SHARE |
share handle to use |
CURLOPT_SOCKOPTDATA |
pointer to pass to sockopt callback |
CURLOPT_SOCKOPTFUNCTION |
callback for setting socket options |
CURLOPT_SOCKS5_AUTH |
methods for SOCKS5 proxy authentication |
CURLOPT_SOCKS5_GSSAPI_NEC |
socks proxy gssapi negotiation protection |
CURLOPT_SOCKS5_GSSAPI_SERVICE |
SOCKS5 proxy authentication service name |
CURLOPT_SSH_AUTH_TYPES |
auth types for SFTP and SCP |
CURLOPT_SSH_COMPRESSION |
enable SSH compression |
CURLOPT_SSH_HOST_PUBLIC_KEY_MD5 |
MD5 checksum of SSH server public key |
CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 |
SHA256 hash of SSH server public key |
CURLOPT_SSH_HOSTKEYDATA |
pointer to pass to the SSH host key callback |
CURLOPT_SSH_HOSTKEYFUNCTION |
callback to check host key |
CURLOPT_SSH_KEYDATA |
pointer passed to the SSH key callback |
CURLOPT_SSH_KEYFUNCTION |
callback for known host matching logic |
CURLOPT_SSH_KNOWNHOSTS |
filename holding the SSH known hosts |
CURLOPT_SSH_PRIVATE_KEYFILE |
private key file for SSH auth |
CURLOPT_SSH_PUBLIC_KEYFILE |
public key file for SSH auth |
CURLOPT_SSL_CIPHER_LIST |
ciphers to use for TLS |
CURLOPT_SSL_CTX_DATA |
pointer passed to ssl_ctx callback |
CURLOPT_SSL_CTX_FUNCTION |
SSL context callback for OpenSSL, wolfSSL or mbedTLS |
CURLOPT_SSL_EC_CURVES |
key exchange curves |
CURLOPT_SSL_ENABLE_ALPN |
Application Layer Protocol Negotiation |
CURLOPT_SSL_ENABLE_NPN |
use NPN |
CURLOPT_SSL_FALSESTART |
TLS false start |
CURLOPT_SSL_OPTIONS |
SSL behavior options |
CURLOPT_SSL_SESSIONID_CACHE |
use the SSL session-ID cache |
CURLOPT_SSL_VERIFYHOST |
verify the certificate's name against host |
CURLOPT_SSL_VERIFYPEER |
verify the peer's SSL certificate |
CURLOPT_SSL_VERIFYSTATUS |
verify the certificate's status |
CURLOPT_SSLCERT_BLOB |
SSL client certificate from memory blob |
CURLOPT_SSLCERT |
SSL client certificate |
CURLOPT_SSLCERTTYPE |
type of client SSL certificate |
CURLOPT_SSLENGINE_DEFAULT |
make SSL engine default |
CURLOPT_SSLENGINE |
SSL engine identifier |
CURLOPT_SSLKEY_BLOB |
private key for client cert from memory blob |
CURLOPT_SSLKEY |
private keyfile for TLS and SSL client cert |
CURLOPT_SSLKEYTYPE |
type of the private key file |
CURLOPT_SSLVERSION |
preferred TLS/SSL version |
CURLOPT_STDERR |
redirect stderr to another stream |
CURLOPT_STREAM_DEPENDS_E |
stream this transfer depends on exclusively |
CURLOPT_STREAM_DEPENDS |
stream this transfer depends on |
CURLOPT_STREAM_WEIGHT |
numerical stream weight |
CURLOPT_SUPPRESS_CONNECT_HEADERS |
suppress proxy CONNECT response headers from user callbacks |
CURLOPT_TCP_FASTOPEN |
TCP Fast Open |
CURLOPT_TCP_KEEPALIVE |
TCP keep-alive probing |
CURLOPT_TCP_KEEPIDLE |
TCP keep-alive idle time wait |
CURLOPT_TCP_KEEPINTVL |
TCP keep-alive interval |
CURLOPT_TCP_NODELAY |
the TCP_NODELAY option |
CURLOPT_TELNETOPTIONS |
set of telnet options |
CURLOPT_TFTP_BLKSIZE |
TFTP block size |
CURLOPT_TFTP_NO_OPTIONS |
send no TFTP options requests |
CURLOPT_TIMECONDITION |
select condition for a time request |
CURLOPT_TIMEOUT_MS |
maximum time the transfer is allowed to complete |
CURLOPT_TIMEOUT |
maximum time the transfer is allowed to complete |
CURLOPT_TIMEVALUE_LARGE |
time value for conditional |
CURLOPT_TIMEVALUE |
time value for conditional |
CURLOPT_TLS13_CIPHERS |
ciphers suites to use for TLS 1.3 |
CURLOPT_TLSAUTH_PASSWORD |
password to use for TLS authentication |
CURLOPT_TLSAUTH_TYPE |
TLS authentication methods |
CURLOPT_TLSAUTH_USERNAME |
username to use for TLS authentication |
CURLOPT_TRAILERDATA |
pointer passed to trailing headers callback |
CURLOPT_TRAILERFUNCTION |
callback for sending trailing headers |
CURLOPT_TRANSFER_ENCODING |
ask for HTTP Transfer Encoding |
CURLOPT_TRANSFERTEXT |
request a text based transfer for FTP |
CURLOPT_UNIX_SOCKET_PATH |
Unix domain socket |
CURLOPT_UNRESTRICTED_AUTH |
send credentials to other hosts too |
CURLOPT_UPKEEP_INTERVAL_MS |
connection upkeep interval |
CURLOPT_UPLOAD_BUFFERSIZE |
upload buffer size |
CURLOPT_UPLOAD |
data upload |
CURLOPT_URL |
URL for this transfer |
CURLOPT_USE_SSL |
request using SSL / TLS for the transfer |
CURLOPT_USERAGENT |
HTTP user-agent header |
CURLOPT_USERNAME |
username to use in authentication |
CURLOPT_USERPWD |
username and password to use in authentication |
CURLOPT_VERBOSE |
verbose mode |
CURLOPT_WILDCARDMATCH |
directory wildcard transfers |
CURLOPT_WRITEDATA |
pointer passed to the write callback |
CURLOPT_WRITEFUNCTION |
callback for writing received data |
CURLOPT_WS_OPTIONS |
WebSocket behavior options |
CURLOPT_XFERINFODATA |
pointer passed to the progress callback |
CURLOPT_XFERINFOFUNCTION |
progress meter callback |
CURLOPT_XOAUTH2_BEARER |
OAuth 2.0 access token |