chiark / gitweb /
Fix mis-merged trackdb_open().
[disorder] / lib / charset.c
CommitLineData
460b9539 1/*
2 * This file is part of DisOrder.
5aff007d 3 * Copyright (C) 2004, 2005, 2007, 2008 Richard Kettlewell
460b9539 4 *
e7eb3a27 5 * This program is free software: you can redistribute it and/or modify
460b9539 6 * it under the terms of the GNU General Public License as published by
e7eb3a27 7 * the Free Software Foundation, either version 3 of the License, or
460b9539 8 * (at your option) any later version.
e7eb3a27
RK
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
460b9539 15 * You should have received a copy of the GNU General Public License
e7eb3a27 16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
460b9539 17 */
14ad73b9 18/** @file lib/charset.c @brief Character set conversion */
460b9539 19
05b75f8d 20#include "common.h"
460b9539 21
22#include <iconv.h>
460b9539 23#include <errno.h>
24#include <langinfo.h>
25
26#include "mem.h"
27#include "log.h"
28#include "charset.h"
29#include "configuration.h"
460b9539 30#include "vector.h"
11f598d1 31#include "unicode.h"
460b9539 32
14ad73b9
RK
33/** @brief Low-level converstion routine
34 * @param from Source encoding
35 * @param to Destination encoding
36 * @param ptr First byte to convert
37 * @param n Number of bytes to convert
38 * @return Converted text, 0-terminated; or NULL on error.
39 */
460b9539 40static void *convert(const char *from, const char *to,
41 const void *ptr, size_t n) {
42 iconv_t i;
43 size_t len;
44 char *buf = 0, *s, *d;
45 size_t bufsize = 0, sl, dl;
46
47 if((i = iconv_open(to, from)) == (iconv_t)-1)
48 fatal(errno, "error calling iconv_open");
49 do {
50 bufsize = bufsize ? 2 * bufsize : 32;
51 buf = xrealloc_noptr(buf, bufsize);
52 iconv(i, 0, 0, 0, 0);
53 s = (char *)ptr;
54 sl = n;
55 d = buf;
56 dl = bufsize;
57 /* (void *) to work around FreeBSD's nonstandard iconv prototype */
58 len = iconv(i, (void *)&s, &sl, &d, &dl);
59 } while(len == (size_t)-1 && errno == E2BIG);
60 iconv_close(i);
61 if(len == (size_t)-1) {
62 error(errno, "error converting from %s to %s", from, to);
63 return 0;
64 }
65 return buf;
66}
67
14ad73b9 68/** @brief Convert from the local multibyte encoding to UTF-8 */
460b9539 69char *mb2utf8(const char *mb) {
70 return convert(nl_langinfo(CODESET), "UTF-8", mb, strlen(mb) + 1);
71}
72
14ad73b9 73/** @brief Convert from UTF-8 to the local multibyte encoding */
460b9539 74char *utf82mb(const char *utf8) {
75 return convert("UTF-8", nl_langinfo(CODESET), utf8, strlen(utf8) + 1);
76}
77
14ad73b9 78/** @brief Convert from encoding @p from to UTF-8 */
460b9539 79char *any2utf8(const char *from, const char *any) {
80 return convert(from, "UTF-8", any, strlen(any) + 1);
81}
82
14ad73b9 83/** @brief Convert from encoding @p from to the local multibyte encoding */
460b9539 84char *any2mb(const char *from, const char *any) {
85 if(from) return convert(from, nl_langinfo(CODESET), any, strlen(any) + 1);
86 else return xstrdup(any);
87}
88
14ad73b9 89/** @brief Convert from encoding @p from to encoding @p to */
460b9539 90char *any2any(const char *from,
91 const char *to,
92 const char *any) {
93 if(from || to) return convert(from, to, any, strlen(any) + 1);
94 else return xstrdup(any);
95}
96
61507e3c
RK
97/** @brief Truncate a string for display purposes
98 * @param s Pointer to UTF-8 string
99 * @param max Maximum number of columns
100 * @return @p or truncated string (never NULL)
101 *
11f598d1
RK
102 * Returns a string that is no longer than @p max graphemes long and is either
103 * (canonically) equal to @p s or is a truncated form of it with an ellipsis
104 * appended.
105 *
106 * We don't take display width into account (tricky for HTML!) and we don't
107 * attempt to implement the Bidi algorithm. If you have track names for which
108 * either of these matter in practice then get in touch.
61507e3c
RK
109 */
110const char *truncate_for_display(const char *s, long max) {
11f598d1
RK
111 uint32_t *s32;
112 size_t l32, cut;
113 utf32_iterator it;
baee3e3a 114 long graphemes;
61507e3c 115
11f598d1
RK
116 /* Convert to UTF-32 for processing */
117 if(!(s32 = utf8_to_utf32(s, strlen(s), &l32)))
118 return 0;
119 it = utf32_iterator_new(s32, l32);
120 cut = l32;
baee3e3a
RK
121 graphemes = 0; /* # of graphemes left of it */
122 while(graphemes <= max && utf32_iterator_where(it) < l32) {
123 if(graphemes == max - 1)
124 cut = utf32_iterator_where(it);
11f598d1
RK
125 utf32_iterator_advance(it, 1);
126 if(utf32_iterator_grapheme_boundary(it))
baee3e3a 127 ++graphemes;
11f598d1 128 }
baee3e3a 129 if(graphemes > max) { /* we need to cut */
11f598d1
RK
130 s32[cut] = 0x2026; /* HORIZONTAL ELLIPSIS */
131 l32 = cut + 1;
132 s = utf32_to_utf8(s32, l32, 0);
61507e3c 133 }
11f598d1
RK
134 xfree(s32);
135 return s;
61507e3c
RK
136}
137
460b9539 138/*
139Local Variables:
140c-basic-offset:2
141comment-column:40
11f598d1
RK
142fill-column:79
143indent-tabs-mode:nil
460b9539 144End:
145*/