/**************************************************************************** * libs/libc/wchar/lib_wcswidth.c * * Copyright © 2005-2014 Rich Felker, et al. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: wcswidth * * Description: * Determine columns needed for a fixed-size wide charcater string * * Input Parameters: * wcs - the wide character string need to calculate * n - the length the wide character string * * Returned Value: * Return the number of columns needed to represent the wide-character * string pointed by "wcs", but at most "n" wide character. If a * nonprintable wide character occurs among these characters, -1 is * returned * ****************************************************************************/ int wcswidth(FAR const wchar_t *wcs, size_t n) { int l = 0; int k = 0; for (; n-- && *wcs && (k = wcwidth(*wcs)) >= 0; l += k, wcs++); return k < 0 ? k : l; }