String_InStringW

Find a substring in a zero terminated source string. InString searches for a substring (lpszSubString) in a larger string (lpszString) and if it is found, it returns its starting position in RAX. It uses a one (1) based character index (1st character is 1, 2nd is 2 etc…) for both the qwStartPosition parameter and the returned character position.

String_InStringW PROTO qwStartPosition:QWORD, lpszString:QWORD, lpszSubString:QWORD

Parameters

  • qwStartPosition - Starting position to search for the substring.

  • lpszString - Address of string to be searched.

  • lpszSubString - Address of substring to search for within the main string.

Returns

If the function succeeds, it returns the 1 based index of the start of the substring or 0 if no match is found.

Notes

If the function fails, the following error values apply:

-1 = substring same length or longer than main string. -2 = qwStartPosition parameter out of range (less than 1 or greater than main string length) This function as based on the MASM32 Library function: ucFind

See Also

String_CountW, String_SubstringW