/* Look at first character in UTF-8 string. Copyright (C) 1999-2000, 2002, 2006-2007 Free Software Foundation, Inc. Written by Bruno Haible , 2002. This program is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2, 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include /* Specification. */ #include "unistr.h" int u8_mblen (const uint8_t *s, size_t n) { if (n > 0) { /* Keep in sync with unistr.h and utf8-ucs4.c. */ uint8_t c = *s; if (c < 0x80) return (c != 0 ? 1 : 0); if (c >= 0xc2) { if (c < 0xe0) { if (n >= 2 #if CONFIG_UNICODE_SAFETY && (s[1] ^ 0x80) < 0x40 #endif ) return 2; } else if (c < 0xf0) { if (n >= 3 #if CONFIG_UNICODE_SAFETY && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 && (c >= 0xe1 || s[1] >= 0xa0) && (c != 0xed || s[1] < 0xa0) #endif ) return 3; } else if (c < 0xf8) { if (n >= 4 #if CONFIG_UNICODE_SAFETY && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 && (s[3] ^ 0x80) < 0x40 && (c >= 0xf1 || s[1] >= 0x90) #if 1 && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90)) #endif #endif ) return 4; } #if 0 else if (c < 0xfc) { if (n >= 5 #if CONFIG_UNICODE_SAFETY && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40 && (c >= 0xf9 || s[1] >= 0x88) #endif ) return 5; } else if (c < 0xfe) { if (n >= 6 #if CONFIG_UNICODE_SAFETY && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40 && (s[5] ^ 0x80) < 0x40 && (c >= 0xfd || s[1] >= 0x84) #endif ) return 6; } #endif } } /* invalid or incomplete multibyte character */ return -1; }