summaryrefslogtreecommitdiff
path: root/usr/src/lib/iconv_modules/zh/common/zh_TW-big5%zh_CN.gbk.c
blob: c4176b3bc0415bd18eb3f9d78a5ea27c5acc9dc3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 *	Copyright(c) 1998 Sun Microsystems, Inc.
 *	All rights reserved.
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <big5_gb18030.h>

#define NON_ID_CHAR '_'	/* non-identifier charactor */
#define MSB 0x80
#define ONEBYTE 0xff

typedef struct _icv_state {
	char keepc[2];	/* maximum # byte of BIG5 charactor */
	short cstate;
	int _errno;		/* internal errno */
} _iconv_st;

enum _CSTATE { C0, C1 };

int big5_2nd_byte(char inbuf);
int big5_to_gbk(char keepc[], char *buf, size_t buflen);
int binsearch(unsigned long x, table_t table[], int n);

/*
 *	Open; called from iconv_open()
 */
void * _icv_open() {
	_iconv_st * st;

	if ((st = (_iconv_st *) malloc(sizeof(_iconv_st))) == NULL) {
		errno = ENOMEM;
		return ((void *) -1);
	}

	st->cstate = C0;
	st->_errno = 0;

	return ((void *) st);
}

/*
 *	Close; called from iconv_close()
 */
void _icv_close(_iconv_st * st) {
	if (!st)
		errno = EBADF;
	else
		free(st);
}

/*
 *	Actual conversion; called from iconv()
 */

size_t _icv_iconv(_iconv_st * st, char **inbuf, size_t *inbytesleft,
					char ** outbuf, size_t *outbytesleft) {
	int n;
	if (st == NULL) {
		errno = EBADF;
		return ((size_t) -1);
	}

	if (inbuf == NULL || *inbuf == NULL) {	/* Reset request. */
		st->cstate = C0;
		st->_errno = 0;
		return ((size_t) 0);
	}

	errno = st->_errno = 0;

	while (*inbytesleft > 0 && *outbytesleft > 0) {
		switch (st->cstate) {
			case C0:
				if (**inbuf & MSB) {	/* big5 charactor */
					st->keepc[0] = (**inbuf);
					st->cstate = C1;
				} else {	/* ASCII */
					**outbuf = **inbuf;
					(*outbuf)++;
					(*outbytesleft)--;
				}
				break;
			case C1:	/* Big5 charactor 2nd byte */
				if (big5_2nd_byte(**inbuf) == 0) {
					st->keepc[1] = (**inbuf);
					n = big5_to_gbk(st->keepc, *outbuf, *outbytesleft);
					if (n > 0) {
						(*outbuf) += n;
						(*outbytesleft) -= n;

						st->cstate = C0;
					} else {
						st->_errno = errno = E2BIG;
					}
				} else {	/* illegal input */
					st->_errno = errno =EILSEQ;
				}
				break;
			default:
				st->_errno = errno = EILSEQ;
				st->cstate = C0;
				break;
		}

		if (st->_errno) break;

		(*inbuf) ++;
		(*inbytesleft)--;

	}

	if (errno) return ((size_t) -1);

	if (*inbytesleft == 0 && st->cstate != C0) {
		errno = EINVAL;
		return ((size_t) -1);
	}

	if (*inbytesleft > 0 && *outbytesleft == 0) {
		errno = E2BIG;
		return (size_t)-1;
	}

	return (size_t)(*inbytesleft);
}

/*
 *	Test whether inbuf is a valid character for
 *	2nd byte of BIG5 charactor:
 *	Return:	0 --- valid BIG5 2nd byte
 *			1 --- invalid BIG5 2nd byte
 */
int big5_2nd_byte(inbuf)
char inbuf;
{
	unsigned int buf = (unsigned int)(inbuf & ONEBYTE);

	if ((buf >= 0x40) && (buf <= 0xfe))
		return 0;
	return 1;
}

/*
 *	big5_to_gbk: Convert Big5 to gbk.
 *	Return:	>0 --- converted with enough space in output buffer
 *			=0 --- no space in outbuf
 */

int big5_to_gbk(char keepc[], char *buf, size_t buflen) {

	unsigned long gbk_val;
	int index;
	unsigned long big5_val;

	if (buflen < 2) {
		errno = E2BIG;
		return 0;
	}

	big5_val = ((keepc[0] & ONEBYTE) << 8) + (keepc[1] & ONEBYTE);
	index = binsearch(big5_val, big5_gbk_tab, BIG5MAX);
	if (index >= 0) {
		gbk_val = big5_gbk_tab[index].value;
		*buf = (gbk_val >> 8) & ONEBYTE;
		*(buf + 1) = gbk_val & ONEBYTE;
	} else
		*buf = *(buf + 1) = (char)NON_ID_CHAR;
	return 2;
}

/*
 *	binsearch()
 */
int binsearch(unsigned long x, table_t table[], int n) {
	int low, high, mid;

	low = 0;
	high = n - 1;
	while (low <= high) {
		mid = (low + high) >> 1;
		if (x < table[mid].key)
			high = mid - 1;
		else if (x > table[mid].key)
			low = mid + 1;
		else
			return mid;
	}
	return -1;
}