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460b9539 | 1 | /* |
2 | * This file is part of DisOrder. | |
3 | * Copyright (C) 2004, 2005 Richard Kettlewell | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
14ad73b9 | 20 | /** @file lib/charset.c @brief Character set conversion */ |
460b9539 | 21 | |
22 | #include <config.h> | |
23 | #include "types.h" | |
24 | ||
25 | #include <iconv.h> | |
26 | #include <string.h> | |
27 | #include <errno.h> | |
28 | #include <langinfo.h> | |
29 | ||
30 | #include "mem.h" | |
31 | #include "log.h" | |
32 | #include "charset.h" | |
33 | #include "configuration.h" | |
34 | #include "utf8.h" | |
35 | #include "vector.h" | |
61507e3c | 36 | #include "unidata.h" |
460b9539 | 37 | |
14ad73b9 RK |
38 | /** @brief Low-level converstion routine |
39 | * @param from Source encoding | |
40 | * @param to Destination encoding | |
41 | * @param ptr First byte to convert | |
42 | * @param n Number of bytes to convert | |
43 | * @return Converted text, 0-terminated; or NULL on error. | |
44 | */ | |
460b9539 | 45 | static void *convert(const char *from, const char *to, |
46 | const void *ptr, size_t n) { | |
47 | iconv_t i; | |
48 | size_t len; | |
49 | char *buf = 0, *s, *d; | |
50 | size_t bufsize = 0, sl, dl; | |
51 | ||
52 | if((i = iconv_open(to, from)) == (iconv_t)-1) | |
53 | fatal(errno, "error calling iconv_open"); | |
54 | do { | |
55 | bufsize = bufsize ? 2 * bufsize : 32; | |
56 | buf = xrealloc_noptr(buf, bufsize); | |
57 | iconv(i, 0, 0, 0, 0); | |
58 | s = (char *)ptr; | |
59 | sl = n; | |
60 | d = buf; | |
61 | dl = bufsize; | |
62 | /* (void *) to work around FreeBSD's nonstandard iconv prototype */ | |
63 | len = iconv(i, (void *)&s, &sl, &d, &dl); | |
64 | } while(len == (size_t)-1 && errno == E2BIG); | |
65 | iconv_close(i); | |
66 | if(len == (size_t)-1) { | |
67 | error(errno, "error converting from %s to %s", from, to); | |
68 | return 0; | |
69 | } | |
70 | return buf; | |
71 | } | |
72 | ||
14ad73b9 | 73 | /** @brief Convert from the local multibyte encoding to UTF-8 */ |
460b9539 | 74 | char *mb2utf8(const char *mb) { |
75 | return convert(nl_langinfo(CODESET), "UTF-8", mb, strlen(mb) + 1); | |
76 | } | |
77 | ||
14ad73b9 | 78 | /** @brief Convert from UTF-8 to the local multibyte encoding */ |
460b9539 | 79 | char *utf82mb(const char *utf8) { |
80 | return convert("UTF-8", nl_langinfo(CODESET), utf8, strlen(utf8) + 1); | |
81 | } | |
82 | ||
14ad73b9 | 83 | /** @brief Convert from encoding @p from to UTF-8 */ |
460b9539 | 84 | char *any2utf8(const char *from, const char *any) { |
85 | return convert(from, "UTF-8", any, strlen(any) + 1); | |
86 | } | |
87 | ||
14ad73b9 | 88 | /** @brief Convert from encoding @p from to the local multibyte encoding */ |
460b9539 | 89 | char *any2mb(const char *from, const char *any) { |
90 | if(from) return convert(from, nl_langinfo(CODESET), any, strlen(any) + 1); | |
91 | else return xstrdup(any); | |
92 | } | |
93 | ||
14ad73b9 | 94 | /** @brief Convert from encoding @p from to encoding @p to */ |
460b9539 | 95 | char *any2any(const char *from, |
96 | const char *to, | |
97 | const char *any) { | |
98 | if(from || to) return convert(from, to, any, strlen(any) + 1); | |
99 | else return xstrdup(any); | |
100 | } | |
101 | ||
61507e3c RK |
102 | /** @brief Return nonzero if @p c is a combining character */ |
103 | static int combining(int c) { | |
104 | if(c < UNICODE_NCHARS) { | |
e5a5a138 | 105 | const struct unidata *const ud = &unidata[c / UNICODE_MODULUS][c % UNICODE_MODULUS]; |
61507e3c | 106 | |
14523635 | 107 | return ud->general_category == unicode_General_Category_Mn || ud->ccc != 0; |
61507e3c RK |
108 | } |
109 | /* Assume unknown characters are noncombining */ | |
110 | return 0; | |
111 | } | |
112 | ||
113 | /** @brief Truncate a string for display purposes | |
114 | * @param s Pointer to UTF-8 string | |
115 | * @param max Maximum number of columns | |
116 | * @return @p or truncated string (never NULL) | |
117 | * | |
118 | * We don't correctly support bidi or double-width characters yet, nor | |
119 | * locate default grapheme cluster boundaries for saner truncation. | |
120 | */ | |
121 | const char *truncate_for_display(const char *s, long max) { | |
122 | const char *t = s, *r, *cut = 0; | |
123 | char *truncated; | |
124 | uint32_t c; | |
125 | long n = 0; | |
126 | ||
127 | /* We need to discover two things: firstly whether the string is | |
128 | * longer than @p max glyphs and secondly if it is not, where to cut | |
129 | * the string. | |
130 | * | |
131 | * Combining characters follow their base character (unicode | |
132 | * standard 5.0 s2.11), so after each base character we must | |
133 | */ | |
134 | while(*t) { | |
135 | PARSE_UTF8(t, c, return s); | |
136 | if(combining(c)) | |
137 | /* This must be an initial combining character. We just skip it. */ | |
138 | continue; | |
139 | /* So c must be a base character. It may be followed by any | |
140 | * number of combining characters. We advance past them. */ | |
141 | do { | |
142 | r = t; | |
143 | PARSE_UTF8(t, c, return s); | |
144 | } while(combining(c)); | |
145 | /* Last character wasn't a combining character so back up */ | |
146 | t = r; | |
147 | ++n; | |
148 | /* So now there are N glyphs before position T. We might | |
149 | * therefore have reached the cut position. */ | |
150 | if(n == max - 3) | |
151 | cut = t; | |
152 | } | |
153 | /* If the string is short enough we return it unmodified */ | |
154 | if(n < max) | |
155 | return s; | |
156 | truncated = xmalloc_noptr(cut - s + 4); | |
157 | memcpy(truncated, s, cut - s); | |
158 | strcpy(truncated + (cut - s), "..."); | |
159 | return truncated; | |
160 | } | |
161 | ||
460b9539 | 162 | /* |
163 | Local Variables: | |
164 | c-basic-offset:2 | |
165 | comment-column:40 | |
166 | End: | |
167 | */ |