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Locates the first occurrence of a null-terminated substring in a null-terminated string.

Header file:


Implemented by:


Called by:

Client applications and service providers

  LPCTSTR lpsz,
  LPCTSTR lpszKey


  • lpsz
    [in] Pointer to the null-terminated string to be searched. The lpsz parameter must not exceed 65536 characters.

  • lpszKey
    [in] Pointer to the null-terminated substring to be searched for. The lpszKey parameter must not exceed 65536 characters.

Return Value

SzFindSz returns a pointer to the first character of the first occurrence of the substring in the string. If the substring does not occur anywhere in the string, if lpszKey is larger than lpsz, or if either parameter is NULL, a value of NULL is returned.


The SzFindSz function searches for an exact match only; it is sensitive to case and diacritical differences. Searches in Unicode and DBCS formats are supported. The length limit on both parameters is in characters, not necessarily bytes.