1/* Word breaks in strings.
2   Copyright (C) 2001-2003, 2006-2010 Free Software Foundation, Inc.
3   Written by Bruno Haible <bruno@clisp.org>, 2009.
4
5   This program is free software: you can redistribute it and/or modify it
6   under the terms of the GNU Lesser General Public License as published
7   by the Free Software Foundation; either version 3 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,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18#include <config.h>
19
20/* Specification.  */
21#include "uniwbrk.h"
22
23#include <stdlib.h>
24#include <string.h>
25
26#include "c-ctype.h"
27#include "localcharset.h"
28#include "uniconv.h"
29#include "unilbrk/ulc-common.h"
30
31/* Word breaks of a string in an arbitrary encoding.
32
33   We convert the input string to Unicode.
34
35   The standardized Unicode encodings are UTF-8, UCS-2, UCS-4, UTF-16,
36   UTF-16BE, UTF-16LE, UTF-7.  UCS-2 supports only characters up to
37   \U0000FFFF.  UTF-16 and variants support only characters up to
38   \U0010FFFF.  UTF-7 is way too complex and not supported by glibc-2.1.
39   UCS-4 specification leaves doubts about endianness and byte order mark.
40   glibc currently interprets it as big endian without byte order mark,
41   but this is not backed by an RFC.  So we use UTF-8. It supports
42   characters up to \U7FFFFFFF and is unambiguously defined.  */
43
44void
45ulc_wordbreaks (const char *s, size_t n, char *p)
46{
47  if (n > 0)
48    {
49      const char *encoding = locale_charset ();
50
51      if (is_utf8_encoding (encoding))
52        u8_wordbreaks ((const uint8_t *) s, n, p);
53      else
54        {
55          /* Convert the string to UTF-8 and build a translation table
56             from offsets into s to offsets into the translated string.  */
57          size_t *offsets = (size_t *) malloc (n * sizeof (size_t));
58
59          if (offsets != NULL)
60            {
61              uint8_t *t;
62              size_t m;
63
64              t = u8_conv_from_encoding (encoding, iconveh_question_mark,
65                                         s, n, offsets, NULL, &m);
66              if (t != NULL)
67                {
68                  char *q = (char *) (m > 0 ? malloc (m) : NULL);
69
70                  if (m == 0 || q != NULL)
71                    {
72                      size_t i;
73
74                      /* Determine the word breaks of the UTF-8 string.  */
75                      u8_wordbreaks (t, m, q);
76
77                      /* Translate the result back to the original string.  */
78                      memset (p, 0, n);
79                      for (i = 0; i < n; i++)
80                        if (offsets[i] != (size_t)(-1))
81                          p[i] = q[offsets[i]];
82
83                      free (q);
84                      free (t);
85                      free (offsets);
86                      return;
87                    }
88                  free (t);
89                }
90              free (offsets);
91            }
92
93          /* Impossible to convert.  */
94#if C_CTYPE_ASCII
95          if (is_all_ascii (s, n))
96            {
97              /* ASCII is a subset of UTF-8.  */
98              u8_wordbreaks ((const uint8_t *) s, n, p);
99              return;
100            }
101#endif
102          /* We have a non-ASCII string and cannot convert it.
103             Don't produce any word breaks.  */
104          memset (p, 0, n);
105        }
106    }
107}
108
109
110#ifdef TEST
111
112#include <locale.h>
113#include <stdio.h>
114#include <stdlib.h>
115
116/* Read the contents of an input stream, and return it, terminated with a NUL
117   byte. */
118char *
119read_file (FILE *stream)
120{
121#define BUFSIZE 4096
122  char *buf = NULL;
123  int alloc = 0;
124  int size = 0;
125  int count;
126
127  while (! feof (stream))
128    {
129      if (size + BUFSIZE > alloc)
130        {
131          alloc = alloc + alloc / 2;
132          if (alloc < size + BUFSIZE)
133            alloc = size + BUFSIZE;
134          buf = realloc (buf, alloc);
135          if (buf == NULL)
136            {
137              fprintf (stderr, "out of memory\n");
138              exit (1);
139            }
140        }
141      count = fread (buf + size, 1, BUFSIZE, stream);
142      if (count == 0)
143        {
144          if (ferror (stream))
145            {
146              perror ("fread");
147              exit (1);
148            }
149        }
150      else
151        size += count;
152    }
153  buf = realloc (buf, size + 1);
154  if (buf == NULL)
155    {
156      fprintf (stderr, "out of memory\n");
157      exit (1);
158    }
159  buf[size] = '\0';
160  return buf;
161#undef BUFSIZE
162}
163
164int
165main (int argc, char * argv[])
166{
167  setlocale (LC_CTYPE, "");
168  if (argc == 1)
169    {
170      /* Display all the word breaks in the input string.  */
171      char *input = read_file (stdin);
172      int length = strlen (input);
173      char *breaks = malloc (length);
174      int i;
175
176      ulc_wordbreaks (input, length, breaks);
177
178      for (i = 0; i < length; i++)
179        {
180          switch (breaks[i])
181            {
182            case 1:
183              putc ('|', stdout);
184              break;
185            case 0:
186              break;
187            default:
188              abort ();
189            }
190          putc (input[i], stdout);
191        }
192
193      free (breaks);
194
195      return 0;
196    }
197  else
198    return 1;
199}
200
201#endif /* TEST */
202