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) /* */ 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 }