2013-04-06 16:48:33 +02:00

78 lines
2.1 KiB
C

/* Conversion UCS-4 to UTF-8.
Copyright (C) 2002 Free Software Foundation, Inc.
Written by Bruno Haible <haible@clisp.cons.org>, 2002.
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 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <stddef.h>
/* Return the length (number of units) of the UTF-8 representation of uc,
after storing it at S. Return -1 upon failure, -2 if the number of
available units, N, is too small. */
static int
u8_uctomb_aux (unsigned char *s, unsigned int uc, int n)
{
int count;
if (uc < 0x80)
count = 1;
else if (uc < 0x800)
count = 2;
else if (uc < 0x10000)
count = 3;
#if 0
else if (uc < 0x200000)
count = 4;
else if (uc < 0x4000000)
count = 5;
else if (uc <= 0x7fffffff)
count = 6;
#else
else if (uc < 0x110000)
count = 4;
#endif
else
return -1;
if (n < count)
return -2;
switch (count) /* note: code falls through cases! */
{
#if 0
case 6: s[5] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x4000000;
case 5: s[4] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x200000;
#endif
case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
case 1: s[0] = uc;
}
return count;
}
static inline int
u8_uctomb (unsigned char *s, unsigned int uc, int n)
{
if (uc < 0x80 && n > 0)
{
s[0] = uc;
return 1;
}
else
return u8_uctomb_aux (s, uc, n);
}