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| .\" * Project ___| | | | _ \| | |
| .\" * / __| | | | |_) | | |
| .\" * | (__| |_| | _ <| |___ |
| .\" * \___|\___/|_| \_\_____| |
| .\" * |
| .\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. |
| .\" * |
| .\" * This software is licensed as described in the file COPYING, which |
| .\" * you should have received as part of this distribution. The terms |
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| .\" ************************************************************************** |
| .\" |
| .TH CURLOPT_INTERFACE 3 "17 Jun 2014" libcurl libcurl |
| .SH NAME |
| CURLOPT_INTERFACE \- source interface for outgoing traffic |
| .SH SYNOPSIS |
| .nf |
| #include <curl/curl.h> |
| |
| CURLcode curl_easy_setopt(CURL *handle, CURLOPT_INTERFACE, char *interface); |
| .fi |
| .SH DESCRIPTION |
| Pass a char * as parameter. This sets the \fIinterface\fP name to use as |
| outgoing network interface. The name can be an interface name, an IP address, |
| or a host name. |
| |
| If the parameter starts with "if!" then it is treated only as an interface |
| name. If the parameter starts with \&"host!" it is treated as either an IP |
| address or a hostname. |
| |
| If "if!" is specified but the parameter does not match an existing interface, |
| \fICURLE_INTERFACE_FAILED\fP is returned from the libcurl function used to |
| perform the transfer. |
| |
| libcurl does not support using network interface names for this option on |
| Windows. |
| |
| We strongly advise against specifying the interface with a hostname, as it |
| causes libcurl to do a blocking name resolve call to retrieve the IP |
| address. That name resolve operation does \fBnot\fP use DNS-over-HTTPS even if |
| \fICURLOPT_DOH_URL(3)\fP is set. |
| |
| The application does not have to keep the string around after setting this |
| option. |
| .SH DEFAULT |
| NULL, use whatever the TCP stack finds suitable |
| .SH PROTOCOLS |
| All |
| .SH EXAMPLE |
| .nf |
| CURL *curl = curl_easy_init(); |
| if(curl) { |
| curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin"); |
| |
| curl_easy_setopt(curl, CURLOPT_INTERFACE, "eth0"); |
| |
| ret = curl_easy_perform(curl); |
| |
| curl_easy_cleanup(curl); |
| } |
| .fi |
| .SH AVAILABILITY |
| The "if!" and "host!" syntax was added in 7.24.0. |
| .SH RETURN VALUE |
| Returns CURLE_OK on success or |
| CURLE_OUT_OF_MEMORY if there was insufficient heap space. |
| .SH "SEE ALSO" |
| .BR CURLOPT_SOCKOPTFUNCTION (3), |
| .BR CURLOPT_TCP_NODELAY (3) |
