/* Determine number of screen columns needed for a size-bounded wide string. Copyright (C) 1999, 2011-2016 Free Software Foundation, Inc. Written by Bruno Haible , 1999. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ int wcswidth (const wchar_t *s, size_t n) { int count = 0; for (; n > 0; s++, n--) { wchar_t c = *s; if (c == (wchar_t)'\0') break; { int width = wcwidth (c); if (width < 0) goto found_nonprinting; if (width > INT_MAX - count) goto overflow; count += width; } } return count; found_nonprinting: return -1; overflow: return INT_MAX; }