.\" generated by cd2nroff 0.1 from CURLOPT_FTP_SSL_CCC.md .TH CURLOPT_FTP_SSL_CCC 3 "2025-11-05" libcurl .SH NAME CURLOPT_FTP_SSL_CCC \- switch off SSL again with FTP after auth .SH SYNOPSIS .nf #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SSL_CCC, long how); .fi .SH DESCRIPTION If enabled, this option makes libcurl use CCC (Clear Command Channel). It shuts down the SSL/TLS layer after authenticating. The rest of the control channel communication remains unencrypted. This allows NAT routers to follow the FTP transaction. Pass a long using one of the values below .IP CURLFTPSSL_CCC_NONE do not attempt to use CCC. .IP CURLFTPSSL_CCC_PASSIVE Do not initiate the shutdown, but wait for the server to do it. Do not send a reply. .IP CURLFTPSSL_CCC_ACTIVE Initiate the shutdown and wait for a reply. .SH DEFAULT CURLFTPSSL_CCC_NONE .SH PROTOCOLS This functionality affects ftp only .SH EXAMPLE .nf int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode res; curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/file.txt"); curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_CONTROL); /* go back to clear-text FTP after authenticating */ curl_easy_setopt(curl, CURLOPT_FTP_SSL_CCC, CURLFTPSSL_CCC_ACTIVE); res = curl_easy_perform(curl); curl_easy_cleanup(curl); } } .fi .SH HISTORY \fBCURLFTPSSL_\fP* enums became \fIlong\fP types in 8.16.0, prior to this version a \fIlong\fP cast was necessary when passed to \fIcurl_easy_setopt(3)\fP. .SH AVAILABILITY Added in curl 7.16.1 .SH RETURN VALUE \fIcurl_easy_setopt(3)\fP returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non\-zero means an error occurred, see \fIlibcurl\-errors(3)\fP. .SH SEE ALSO .BR CURLOPT_FTPSSLAUTH (3), .BR CURLOPT_PROTOCOLS_STR (3), .BR CURLOPT_USE_SSL (3)