curl/docs/libcurl/curl_url_set.3

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.TH curl_url_set 3 "6 Aug 2018" "libcurl" "libcurl"
.SH NAME
curl_url_set - set a URL part
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLUcode curl_url_set(CURLU *url,
                       CURLUPart part,
                       const char *content,
                       unsigned int flags)
.fi
.SH DESCRIPTION
Given the \fIurl\fP handle of an already parsed URL, this function lets the
user set/update individual pieces of it.

The \fIpart\fP argument should identify the particular URL part (see list
below) to set or change, with \fIcontent\fP pointing to a null-terminated
string with the new contents for that URL part. The contents should be in the
form and encoding they'd use in a URL: URL encoded.

The application does not have to keep \fIcontent\fP around after a successful
call.

Setting a part to a NULL pointer will effectively remove that part's contents
from the \fICURLU\fP handle.

By default, this API only accepts URLs using schemes for protocols that are
supported built-in. To make libcurl parse URLs generically even for schemes it
does not know about, the \fBCURLU_NON_SUPPORT_SCHEME\fP flags bit must be
set. Otherwise, this function returns \fICURLUE_UNSUPPORTED_SCHEME\fP on URL
schemes it does not recognize.

This function call has no particular maximum length for any provided input
string. In the real world, excessively long field in URLs will cause problems
even if this API accepts them.

When setting or updating contents of individual URL parts, this API might
accept data that would not be otherwise possible to set in the string when it
gets populated as a result of a full URL parse. Beware. If done so, extracting
a full URL later on from such components might render an invalid URL.

The \fIflags\fP argument is a bitmask with independent features.
.SH PARTS
.IP CURLUPART_URL
Allows the full URL of the handle to be replaced. If the handle already is
populated with a URL, the new URL can be relative to the previous.

When successfully setting a new URL, relative or absolute, the handle contents
will be replaced with the information of the newly set URL.

Pass a pointer to a null-terminated string to the \fIurl\fP parameter. The
string must point to a correctly formatted "RFC 3986+" URL or be a NULL
pointer.

Unless \fICURLU_NO_AUTHORITY\fP is set, a blank host name is not allowed in
the URL.
.IP CURLUPART_SCHEME
Scheme cannot be URL decoded on set. libcurl only accepts setting schemes up
to 40 bytes long.
.IP CURLUPART_USER
.IP CURLUPART_PASSWORD
.IP CURLUPART_OPTIONS
The options field is an optional field that might follow the password in the
userinfo part. It is only recognized/used when parsing URLs for the following
schemes: pop3, smtp and imap. This function however allows users to
independently set this field at will.
.IP CURLUPART_HOST
The host name. If it is IDNA the string must then be encoded as your locale
says or UTF-8 (when WinIDN is used). If it is a bracketed IPv6 numeric address
it may contain a zone id (or you can use CURLUPART_ZONEID).

Unless \fICURLU_NO_AUTHORITY\fP is set, a blank host name is not allowed to set.
.IP CURLUPART_ZONEID
If the host name is a numeric IPv6 address, this field can also be set.
.IP CURLUPART_PORT
Port cannot be URL encoded on set. The given port number is provided as a
string and the decimal number must be between 1 and 65535. Anything else will
return an error.
.IP CURLUPART_PATH
If a path is set in the URL without a leading slash, a slash will be prepended
automatically.
.IP CURLUPART_QUERY
The query part will also get spaces converted to pluses when asked to URL
encode on set with the \fICURLU_URLENCODE\fP bit.

If used together with the \fICURLU_APPENDQUERY\fP bit, the provided part is
appended on the end of the existing query.

The question mark in the URL is not part of the actual query contents.
.IP CURLUPART_FRAGMENT
The hash sign in the URL is not part of the actual fragment contents.
.SH FLAGS
The flags argument is zero, one or more bits set in a bitmask.
.IP CURLU_APPENDQUERY
Can be used when setting the \fICURLUPART_QUERY\fP component. The provided new
part will then instead be appended at the end of the existing query - and if
the previous part did not end with an ampersand (&), an ampersand gets
inserted before the new appended part.

When \fICURLU_APPENDQUERY\fP is used together with \fICURLU_URLENCODE\fP, the
first '=' symbol will not be URL encoded.
.IP CURLU_NON_SUPPORT_SCHEME
If set, allows \fIcurl_url_set(3)\fP to set a non-supported scheme.
.IP CURLU_URLENCODE
When set, \fIcurl_url_set(3)\fP URL encodes the part on entry, except for
scheme, port and URL.

When setting the path component with URL encoding enabled, the slash character
will be skipped.

The query part gets space-to-plus conversion before the URL conversion.

This URL encoding is charset unaware and will convert the input on a
byte-by-byte manner.
.IP CURLU_DEFAULT_SCHEME
If set, will make libcurl allow the URL to be set without a scheme and then
sets that to the default scheme: HTTPS. Overrides the \fICURLU_GUESS_SCHEME\fP
option if both are set.
.IP CURLU_GUESS_SCHEME
If set, will make libcurl allow the URL to be set without a scheme and it
instead "guesses" which scheme that was intended based on the host name. If
the outermost sub-domain name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP then
that scheme will be used, otherwise it picks HTTP. Conflicts with the
\fICURLU_DEFAULT_SCHEME\fP option which takes precedence if both are set.
.IP CURLU_NO_AUTHORITY
If set, skips authority checks. The RFC allows individual schemes to omit the
host part (normally the only mandatory part of the authority), but libcurl
cannot know whether this is permitted for custom schemes. Specifying the flag
permits empty authority sections, similar to how file scheme is handled.
.IP CURLU_PATH_AS_IS
When set for \fBCURLUPART_URL\fP, this makes libcurl skip the normalization of
the path. That is the procedure where curl otherwise removes sequences of
dot-slash and dot-dot etc. The same option used for transfers is called
\fICURLOPT_PATH_AS_IS(3)\fP.
.IP CURLU_ALLOW_SPACE
If set, the URL parser allows space (ASCII 32) where possible. The URL
syntax does normally not allow spaces anywhere, but they should be encoded as
%20 or '+'. When spaces are allowed, they are still not allowed in the scheme.
When space is used and allowed in a URL, it will be stored as-is unless
\fICURLU_URLENCODE\fP is also set, which then makes libcurl URL-encode the
space before stored. This affects how the URL will be constructed when
\fIcurl_url_get(3)\fP is subsequently used to extract the full URL or
individual parts. (Added in 7.78.0)
.IP CURLU_DISALLOW_USER
If set, the URL parser will not accept embedded credentials for the
\fBCURLUPART_URL\fP, and will instead return \fBCURLUE_USER_NOT_ALLOWED\fP for
such URLs.
.SH EXAMPLE
.nf
  CURLUcode rc;
  CURLU *url = curl_url();
  rc = curl_url_set(url, CURLUPART_URL, "https://example.com", 0);
  if(!rc) {
    char *scheme;
    /* change it to an FTP URL */
    rc = curl_url_set(url, CURLUPART_SCHEME, "ftp", 0);
  }
  curl_url_cleanup(url);
.fi
.SH AVAILABILITY
Added in 7.62.0. CURLUPART_ZONEID was added in 7.65.0.
.SH RETURN VALUE
Returns a \fICURLUcode\fP error value, which is CURLUE_OK (0) if everything
went fine. See the \fIlibcurl-errors(3)\fP man page for the full list with
descriptions.

The input string passed to \fIcurl_url_set(3)\fP must be shorter than eight
million bytes. Otherwise this function returns \fBCURLUE_MALFORMED_INPUT\fP.

If this function returns an error, no URL part is set.
.SH "SEE ALSO"
.BR curl_url_cleanup "(3), " curl_url "(3), " curl_url_get "(3), "
.BR curl_url_dup "(3), " curl_url_strerror "(3), " CURLOPT_CURLU "(3)"