1 /* Determine number of screen columns needed for a size-bounded wide string.
2 Copyright (C) 1999, 2011-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 1999.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 3 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 int
19 wcswidth (const wchar_t *s, size_t n)
/* ![[previous]](../icons/n_left.png)
![[next]](../icons/n_right.png)
![[first]](../icons/n_first.png)
![[last]](../icons/n_last.png)
![[top]](../icons/top.png)
![[bottom]](../icons/bottom.png)
![[index]](../icons/index.png)
*/
20 {
21 int count = 0;
22 for (; n > 0; s++, n--)
23 {
24 wchar_t c = *s;
25 if (c == (wchar_t)'\0')
26 break;
27 {
28 int width = wcwidth (c);
29 if (width < 0)
30 goto found_nonprinting;
31 if (width > INT_MAX - count)
32 goto overflow;
33 count += width;
34 }
35 }
36 return count;
37
38 found_nonprinting:
39 return -1;
40
41 overflow:
42 return INT_MAX;
43 }