Copy a multi-string into a buffer

Question

I'm using a windows-api that returns a wide-char multi-string as result. The result is same as below:

L"apple\0banana\0orange\0\0"

Is there any standard function or good performance solution to copy this structure to a buffer?

copy_wide_char_multi_string(dst, src); // dst and src are wchar_t arrays

@NeelBasu: No, that is not enough because the source string contains nulls and double-nulls indicates the termination of the string. — masoud, Aug 19 '12 at 12:33
[Obligatory oldnewthing post dealing with double-null-terminated strings](http://blogs.msdn.com/b/oldnewthing/archive/2009/10/08/9904646.aspx) — user786653, Aug 19 '12 at 12:48

Wug · Accepted Answer · 2012-08-19T13:05:46.557

I've never bothered to work with wide character strings so consider this a guideline.

You can implement an algorithm like the following:

wchar_t * wide_string = L"something\0something else\0herp\0derp\0\0";
int size = 0;

int i = wcslen(wide_string + size);     // length of wide string
size += i + 1;                          // length of wide string inc. null terminator
while (true)
{
    int i = wcslen(wide_string + size); // length of wide string
    size += i + 1;                      // length of wide string inc. null terminator
    if (i == 0) break;                  // if length was 0 (2 nulls in a row) break
}
++size;                                 // count final null as part of size

This will give you the size of the data in the buffer. Once you have that you can just use wmemcpy on it

Neel Basu · Answer 2 · 2012-08-19T13:00:42.743

0

You seem to be already knowing size of original array.so create another wchar_t clonned array of same size and simply use std::copy

std::copy(original, original+size, clonned)

edited Aug 19 '12 at 13:00

answered Aug 19 '12 at 12:54

Neel Basu

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Copy a multi-string into a buffer

2 Answers2