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| .TH CURLOPT_UNIX_SOCKET_PATH 3 "October 27, 2021" "libcurl 7.80.0" "curl_easy_setopt options" |
| |
| .SH NAME |
| CURLOPT_UNIX_SOCKET_PATH \- Unix domain socket |
| .SH SYNOPSIS |
| #include <curl/curl.h> |
| |
| CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UNIX_SOCKET_PATH, char *path); |
| .SH DESCRIPTION |
| Enables the use of Unix domain sockets as connection endpoint and sets the path |
| to \fIpath\fP. If \fIpath\fP is NULL, then Unix domain sockets are disabled. An |
| empty string will result in an error at some point, it will not disable use of |
| Unix domain sockets. |
| |
| When enabled, curl will connect to the Unix domain socket instead of |
| establishing a TCP connection to a host. Since no TCP connection is created, |
| curl does not need to resolve the DNS hostname in the URL. |
| |
| The maximum path length on Cygwin, Linux and Solaris is 107. On other platforms |
| it might be even less. |
| |
| Proxy and TCP options such as \fICURLOPT_TCP_NODELAY(3)\fP are not |
| supported. Proxy options such as \fICURLOPT_PROXY(3)\fP have no effect either |
| as these are TCP-oriented, and asking a proxy server to connect to a certain |
| Unix domain socket is not possible. |
| |
| The application does not have to keep the string around after setting this |
| option. |
| .SH DEFAULT |
| Default is NULL, meaning that no Unix domain sockets are used. |
| .SH PROTOCOLS |
| All protocols except for FILE and FTP are supported in theory. HTTP, IMAP, |
| POP3 and SMTP should in particular work (including their SSL/TLS variants). |
| .SH EXAMPLE |
| Given that you have an HTTP server running listening on /tmp/httpd.sock, you |
| can request an HTTP resource with: |
| |
| .nf |
| curl_easy_setopt(curl_handle, CURLOPT_UNIX_SOCKET_PATH, "/tmp/httpd.sock"); |
| curl_easy_setopt(curl_handle, CURLOPT_URL, "http://localhost/"); |
| .fi |
| |
| If you are on Linux and somehow have a need for paths larger than 107 bytes, |
| you could use the proc filesystem to bypass the limitation: |
| |
| .nf |
| int dirfd = open(long_directory_path_to_socket, O_DIRECTORY | O_RDONLY); |
| char path[108]; |
| snprintf(path, sizeof(path), "/proc/self/fd/%d/httpd.sock", dirfd); |
| curl_easy_setopt(curl_handle, CURLOPT_UNIX_SOCKET_PATH, path); |
| /* Be sure to keep dirfd valid until you discard the handle */ |
| .fi |
| .SH AVAILABILITY |
| Added in 7.40.0. |
| .SH RETURN VALUE |
| Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. |
| .SH "SEE ALSO" |
| .BR CURLOPT_ABSTRACT_UNIX_SOCKET "(3), " |
| .BR CURLOPT_OPENSOCKETFUNCTION "(3), " unix "(7), " |