CURLOPT_URL(3)

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2CURLOPT_URL(3)                      libcurl                     CURLOPT_URL(3)
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NAME

7       CURLOPT_URL - URL for this transfer
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SYNOPSIS

10       #include <curl/curl.h>
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12       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_URL, char *URL);
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DESCRIPTION

15       Pass  in  a  pointer to the URL to work with. The parameter should be a
16       char * to a null-terminated string which must  be  URL-encoded  in  the
17       following format:
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19       scheme://host:port/path
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21       For a greater explanation of the format please see RFC 3986.
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23       libcurl  does  not  validate  the syntax or use this variable until the
24       transfer is issued. Even if you set a crazy value  here,  curl_easy_se‐
25       topt(3) will still return CURLE_OK.
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27       If  the  given  URL  is  missing  a  scheme  name (such as "http://" or
28       "ftp://" etc) then libcurl will make a guess based on the host. If  the
29       outermost  sub-domain  name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP
30       then that protocol will be used, otherwise HTTP  will  be  used.  Since
31       7.45.0 guessing can be disabled by setting a default protocol, see CUR‐
32       LOPT_DEFAULT_PROTOCOL(3) for details.
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34       Should the protocol, either that specified by the scheme or deduced  by
35       libcurl  from the host name, not be supported by libcurl then CURLE_UN‐
36       SUPPORTED_PROTOCOL will be  returned  from  either  the  curl_easy_per‐
37       form(3)  or  curl_multi_perform(3)  functions  when  you call them. Use
38       curl_version_info(3) for detailed information of  which  protocols  are
39       supported by the build of libcurl you are using.
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41       CURLOPT_PROTOCOLS(3)  can  be used to limit what protocols libcurl will
42       use for this transfer, independent of what libcurl has been compiled to
43       support.  That  may  be  useful  if you accept the URL from an external
44       source and want to limit the accessibility.
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46       The CURLOPT_URL(3) string will be ignored if CURLOPT_CURLU(3) is set.
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48       CURLOPT_URL(3) or CURLOPT_CURLU(3) must be set  before  a  transfer  is
49       started.
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51       The  application  does not have to keep the string around after setting
52       this option.
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ENCODING

55       The string pointed to in the CURLOPT_URL(3) argument is  generally  ex‐
56       pected  to be a sequence of characters using an ASCII compatible encod‐
57       ing.
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59       If libcurl is built with IDN support, the server name part of  the  URL
60       can  use an "international name" by using the current encoding (accord‐
61       ing to locale) or UTF-8 (when winidn is  used;  or  a  Windows  Unicode
62       build using libidn2).
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64       If  libcurl  is  built without IDN support, the server name is used ex‐
65       actly as specified when passed to the name resolver functions.
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DEFAULT

68       There is no default URL. If this option is not set, no transfer can  be
69       performed.
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SECURITY CONCERNS

72       Applications  may at times find it convenient to allow users to specify
73       URLs for various purposes and that string would then end up fed to this
74       option.
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76       Getting  a  URL from an external untrusted party will bring reasons for
77       several security concerns:
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79       If you have an application that runs as or  in  a  server  application,
80       getting an unfiltered URL can easily trick your application to access a
81       local resource instead of a remote. Protecting yourself against  local‐
82       host accesses is hard when accepting user provided URLs.
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84       Such  custom  URLs can also access other ports than you planned as port
85       numbers are part of the regular URL format. The combination of a  local
86       host  and  a custom port number can allow external users to play tricks
87       with your local services.
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89       Accepting external URLs may also use other protocols  than  http://  or
90       other common ones. Restrict what accept with CURLOPT_PROTOCOLS(3).
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92       User  provided  URLs  can  also be made to point to sites that redirect
93       further on (possibly  to  other  protocols  too).  Consider  your  CUR‐
94       LOPT_FOLLOWLOCATION(3) and CURLOPT_REDIR_PROTOCOLS(3) settings.
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PROTOCOLS

97       All
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EXAMPLE

100       CURL *curl = curl_easy_init();
101       if(curl) {
102         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
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104         curl_easy_perform(curl);
105       }
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AVAILABILITY

108       POP3 and SMTP were added in 7.31.0
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RETURN VALUE

111       Returns  CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insuf‐
112       ficient heap space.
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114       Note that curl_easy_setopt(3) will not actually parse the given  string
115       so  given a bad URL, it will not be detected until curl_easy_perform(3)
116       or similar is called.
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