CURLOPT_PROXY(3)

1CURLOPT_PROXY(3)           curl_easy_setopt options           CURLOPT_PROXY(3)
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NAME

6       CURLOPT_PROXY - set proxy to use
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY, char *proxy);
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DESCRIPTION

14       Set  the proxy to use for the upcoming request. The parameter should be
15       a char * to a zero terminated string holding the host  name  or  dotted
16       numerical  IP  address. A numerical IPv6 address must be written within
17       [brackets].
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19       To specify port number in this string, append :[port] to the end of the
20       host name. The proxy's port number may optionally be specified with the
21       separate option CURLOPT_PROXYPORT(3). If not  specified,  libcurl  will
22       default to using port 1080 for proxies.
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24       The proxy string may be prefixed with [scheme]:// to specify which kind
25       of proxy is used.
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28              http://
29                     HTTP Proxy. Default when no scheme or proxy type is spec‐
30                     ified.
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32              https://
33                     HTTPS  Proxy.  (Added  in  7.52.0 for OpenSSL, GnuTLS and
34                     NSS)
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36              socks4://
37                     SOCKS4 Proxy.
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39              socks4a://
40                     SOCKS4a Proxy. Proxy resolves URL hostname.
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42              socks5://
43                     SOCKS5 Proxy.
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45              socks5h://
46                     SOCKS5 Proxy. Proxy resolves URL hostname.
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48       Without a scheme prefix, CURLOPT_PROXYTYPE(3) can be  used  to  specify
49       which kind of proxy the string identifies.
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51       When  you tell the library to use an HTTP proxy, libcurl will transpar‐
52       ently convert operations to HTTP even if you specify an  FTP  URL  etc.
53       This  may  have an impact on what other features of the library you can
54       use, such as CURLOPT_QUOTE(3) and similar FTP specifics that don't work
55       unless  you  tunnel through the HTTP proxy. Such tunneling is activated
56       with CURLOPT_HTTPPROXYTUNNEL(3).
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58       Setting the proxy string to "" (an empty string) will  explicitly  dis‐
59       able  the  use of a proxy, even if there is an environment variable set
60       for it.
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62       A proxy host string can also  include  protocol  scheme  (http://)  and
63       embedded user + password.
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65       The  application  does not have to keep the string around after setting
66       this option.
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Environment variables

69       libcurl respects the  proxy  environment  variables  named  http_proxy,
70       ftp_proxy, sftp_proxy etc. If set, libcurl will use the specified proxy
71       for that URL scheme. So for a "FTP://" URL, the  ftp_proxy  is  consid‐
72       ered. all_proxy is used if no protocol specific proxy was set.
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74       If no_proxy (or NO_PROXY) is set, it is the exact equivalent of setting
75       the CURLOPT_NOPROXY(3) option.
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77       The CURLOPT_PROXY(3) and CURLOPT_NOPROXY(3) options  override  environ‐
78       ment variables.
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DEFAULT

81       Default is NULL, meaning no proxy is used.
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83       When you set a host name to use, do not assume that there's any partic‐
84       ular single port number used widely for proxies. Specify it!
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PROTOCOLS

87       All except file://. Note that some protocols don't do  very  well  over
88       proxy.
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EXAMPLE

91       CURL *curl = curl_easy_init();
92       if(curl) {
93         curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/file.txt");
94         curl_easy_setopt(curl, CURLOPT_PROXY, "http://proxy:80");
95         curl_easy_perform(curl);
96       }
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AVAILABILITY

99       Since  7.14.1 the proxy environment variable names can include the pro‐
100       tocol scheme.
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102       Since  7.21.7  the  proxy  string  supports  the  socks  protocols   as
103       "schemes".
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105       Since  7.50.2,  unsupported  schemes  in proxy strings cause libcurl to
106       return error.
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RETURN VALUE

109       Returns CURLE_OK if proxies are supported, CURLE_UNKNOWN_OPTION if not,
110       or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
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