libxconv/xconv.c
2017-03-09 14:55:16 +00:00

74 lines
1.1 KiB
C

#include <stdio.h>
#include "charset.h"
static int
add_unicode(char **d, size_t *len, uint16_t u)
{
if (u < 0x80)
{
// 1 byte
if (*len < 1) return 0;
(*d)[0] = u;
(*d)++, *len--;
return 1;
}
if (u < 0x800)
{
// 2 bytes
if (*len < 2) return 0;
(*d)[0] = 0xc0 | ((u >> 6) & 0x1f);
(*d)[1] = 0x80 | (u & 0x3f);
*d += 2, *len -= 2;
return 1;
}
if (u < 0x10000)
{
// 3 bytes
if (*len < 3) return 0;
(*d)[0] = 0xe0 | ((u >> 12) & 0xf);
(*d)[1] = 0x80 | ((u >> 6) & 0x3f);
(*d)[2] = 0x80 | (u & 0x3f);
*d += 3, *len -= 3;
return 1;
}
// 4 byte code point not supported.
return 0;
}
int
xconv(char *src, char *dst, size_t dstlen)
{
size_t len = dstlen;
char *s, *d;
int i;
for (s = src, d = dst; *s && len > 0; s++)
{
// Check for combined character.
if ((*s & 0xf0) == 0xc0 && s[1])
{
icc_t *p;
int k = *s & 0xf;
p = iso6937_combined[k];
for (i = 0; p[i].c; i++)
{
if (p[i].c == (s[1] & 0xff))
{
add_unicode(&d, &len,
iso6937_combined[k][i].u);
break;
}
}
s++;
continue;
}
add_unicode(&d, &len, iso6937_map[*s & 0xff]);
}
*d = '\0';
return dstlen - len;
}