InternetCombineUrlA function (wininet.h)

Article
02/09/2023

Combines a base and relative URL into a single URL. The resultant URL is canonicalized (see InternetCanonicalizeUrl).

Syntax

BOOL InternetCombineUrlA(
  [in]      LPCSTR  lpszBaseUrl,
  [in]      LPCSTR  lpszRelativeUrl,
  [out]     LPSTR   lpszBuffer,
  [in, out] LPDWORD lpdwBufferLength,
  [in]      DWORD   dwFlags
);

Parameters

[in] lpszBaseUrl

Pointer to a null-terminated string that contains the base URL.

[in] lpszRelativeUrl

Pointer to a null-terminated string that contains the relative URL.

[out] lpszBuffer

Pointer to a buffer that receives the combined URL.

[in, out] lpdwBufferLength

Pointer to a variable that contains the size of the lpszBuffer buffer, in characters. If the function succeeds, this parameter receives the size of the combined URL, in characters, not including the null-terminating character. If the function fails, this parameter receives the size of the required buffer, in characters (including the null-terminating character).

[in] dwFlags

Controls the operation of the function. This parameter can be one of the following values.

Value	Meaning
ICU_BROWSER_MODE	Does not encode or decode characters after "#" or "?", and does not remove trailing white space after "?". If this value is not specified, the entire URL is encoded and trailing white space is removed.
ICU_DECODE	Converts all %XX sequences to characters, including escape sequences, before the URL is parsed.
ICU_ENCODE_PERCENT	Encodes any percent signs encountered. By default, percent signs are not encoded. This value is available in Microsoft Internet Explorer 5 and later.
ICU_ENCODE_SPACES_ONLY	Encodes spaces only.
ICU_NO_ENCODE	Does not convert unsafe characters to escape sequences.
ICU_NO_META	Does not remove meta sequences (such as "." and "..") from the URL.

Return value

Returns TRUE if successful, or FALSE otherwise. To get extended error information, call GetLastError. Possible errors include the following.

Return code	Description
ERROR_BAD_PATHNAME	The URLs could not be combined.
ERROR_INSUFFICIENT_BUFFER	The buffer supplied to the function was insufficient or NULL. The value indicated by the lpdwBufferLength parameter will contain the number of bytes required to hold the combined URL.
ERROR_INTERNET_INVALID_URL	The format of the URL is invalid.
ERROR_INVALID_PARAMETER	There is an invalid string, buffer, buffer size, or flags parameter.

Remarks

Note WinINet does not support server implementations. In addition, it should not be used from a service. For server implementations or services use Microsoft Windows HTTP Services (WinHTTP).

Note

The wininet.h header defines InternetCombineUrl as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	wininet.h
Library	Wininet.lib
DLL	Wininet.dll