86 lines
2.0 KiB
Markdown
86 lines
2.0 KiB
Markdown
---
|
|
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
|
|
SPDX-License-Identifier: curl
|
|
Title: CURLOPT_INTERFACE
|
|
Section: 3
|
|
Source: libcurl
|
|
Protocol:
|
|
- All
|
|
See-also:
|
|
- CURLOPT_SOCKOPTFUNCTION (3)
|
|
- CURLOPT_TCP_NODELAY (3)
|
|
- CURLOPT_LOCALPORT (3)
|
|
---
|
|
|
|
# NAME
|
|
|
|
CURLOPT_INTERFACE - source interface for outgoing traffic
|
|
|
|
# SYNOPSIS
|
|
|
|
~~~c
|
|
#include <curl/curl.h>
|
|
|
|
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_INTERFACE, char *interface);
|
|
~~~
|
|
|
|
# DESCRIPTION
|
|
|
|
Pass a char pointer as parameter. This sets the *interface* name to use as
|
|
outgoing network interface. The name can be an interface name, an IP address,
|
|
or a hostname. If you prefer one of these, you can use the following special
|
|
prefixes:
|
|
|
|
* `if!\<name\>` - Interface name
|
|
* `host!\<name\>` - IP address or hostname
|
|
* `ifhost!\<interface\>!\<host\>` - Interface name and IP address or hostname
|
|
|
|
If `if!` or `ifhost!` is specified but the parameter does not match an existing
|
|
interface, *CURLE_INTERFACE_FAILED* 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 **not** use DNS-over-HTTPS even if
|
|
CURLOPT_DOH_URL(3) is set.
|
|
|
|
The application does not have to keep the string around after setting this
|
|
option.
|
|
|
|
# DEFAULT
|
|
|
|
NULL, use whatever the TCP stack finds suitable
|
|
|
|
# EXAMPLE
|
|
|
|
~~~c
|
|
int main(void)
|
|
{
|
|
CURL *curl = curl_easy_init();
|
|
if(curl) {
|
|
CURLcode res;
|
|
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
|
|
|
|
curl_easy_setopt(curl, CURLOPT_INTERFACE, "eth0");
|
|
|
|
res = curl_easy_perform(curl);
|
|
|
|
curl_easy_cleanup(curl);
|
|
}
|
|
}
|
|
~~~
|
|
|
|
# AVAILABILITY
|
|
|
|
The `if!` and `host!` syntax was added in 7.24.0.
|
|
|
|
The `ifhost!` syntax was added in 8.9.0.
|
|
|
|
# RETURN VALUE
|
|
|
|
Returns CURLE_OK on success or
|
|
CURLE_OUT_OF_MEMORY if there was insufficient heap space.
|