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+/* Line breaking of strings.
+ Copyright (C) 2001-2003, 2006-2009 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2001.
+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "unilbrk.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "c-ctype.h"
+#include "uniconv.h"
+#include "unilbrk/ulc-common.h"
+
+/* Line breaking of a string in an arbitrary encoding.
+
+ We convert the input string to Unicode.
+
+ The standardized Unicode encodings are UTF-8, UCS-2, UCS-4, UTF-16,
+ UTF-16BE, UTF-16LE, UTF-7. UCS-2 supports only characters up to
+ \U0000FFFF. UTF-16 and variants support only characters up to
+ \U0010FFFF. UTF-7 is way too complex and not supported by glibc-2.1.
+ UCS-4 specification leaves doubts about endianness and byte order mark.
+ glibc currently interprets it as big endian without byte order mark,
+ but this is not backed by an RFC. So we use UTF-8. It supports
+ characters up to \U7FFFFFFF and is unambiguously defined. */
+
+void
+ulc_possible_linebreaks (const char *s, size_t n, const char *encoding,
+ char *p)
+{
+ if (n > 0)
+ {
+ if (is_utf8_encoding (encoding))
+ u8_possible_linebreaks ((const uint8_t *) s, n, encoding, p);
+ else
+ {
+ /* Convert the string to UTF-8 and build a translation table
+ from offsets into s to offsets into the translated string. */
+ size_t *offsets = (size_t *) malloc (n * sizeof (size_t));
+
+ if (offsets != NULL)
+ {
+ uint8_t *t;
+ size_t m;
+
+ t = u8_conv_from_encoding (encoding, iconveh_question_mark,
+ s, n, offsets, NULL, &m);
+ if (t != NULL)
+ {
+ char *q = (char *) (m > 0 ? malloc (m) : NULL);
+
+ if (m == 0 || q != NULL)
+ {
+ size_t i;
+
+ /* Determine the possible line breaks of the UTF-8
+ string. */
+ u8_possible_linebreaks (t, m, encoding, q);
+
+ /* Translate the result back to the original string. */
+ memset (p, UC_BREAK_PROHIBITED, n);
+ for (i = 0; i < n; i++)
+ if (offsets[i] != (size_t)(-1))
+ p[i] = q[offsets[i]];
+
+ free (q);
+ free (t);
+ free (offsets);
+ return;
+ }
+ free (t);
+ }
+ free (offsets);
+ }
+
+ /* Impossible to convert. */
+#if C_CTYPE_ASCII
+ if (is_all_ascii (s, n))
+ {
+ /* ASCII is a subset of UTF-8. */
+ u8_possible_linebreaks ((const uint8_t *) s, n, encoding, p);
+ return;
+ }
+#endif
+ /* We have a non-ASCII string and cannot convert it.
+ Don't produce line breaks except those already present in the
+ input string. All we assume here is that the encoding is
+ minimally ASCII compatible. */
+ {
+ const char *s_end = s + n;
+ while (s < s_end)
+ {
+ *p = (*s == '\n' ? UC_BREAK_MANDATORY : UC_BREAK_PROHIBITED);
+ s++;
+ p++;
+ }
+ }
+ }
+ }
+}
+
+
+#ifdef TEST
+
+#include <stdio.h>
+#include <locale.h>
+#include <string.h>
+
+/* Read the contents of an input stream, and return it, terminated with a NUL
+ byte. */
+char *
+read_file (FILE *stream)
+{
+#define BUFSIZE 4096
+ char *buf = NULL;
+ int alloc = 0;
+ int size = 0;
+ int count;
+
+ while (! feof (stream))
+ {
+ if (size + BUFSIZE > alloc)
+ {
+ alloc = alloc + alloc / 2;
+ if (alloc < size + BUFSIZE)
+ alloc = size + BUFSIZE;
+ buf = realloc (buf, alloc);
+ if (buf == NULL)
+ {
+ fprintf (stderr, "out of memory\n");
+ exit (1);
+ }
+ }
+ count = fread (buf + size, 1, BUFSIZE, stream);
+ if (count == 0)
+ {
+ if (ferror (stream))
+ {
+ perror ("fread");
+ exit (1);
+ }
+ }
+ else
+ size += count;
+ }
+ buf = realloc (buf, size + 1);
+ if (buf == NULL)
+ {
+ fprintf (stderr, "out of memory\n");
+ exit (1);
+ }
+ buf[size] = '\0';
+ return buf;
+#undef BUFSIZE
+}
+
+int
+main (int argc, char * argv[])
+{
+ setlocale (LC_CTYPE, "");
+ if (argc == 1)
+ {
+ /* Display all the break opportunities in the input string. */
+ char *input = read_file (stdin);
+ int length = strlen (input);
+ char *breaks = malloc (length);
+ int i;
+
+ ulc_possible_linebreaks (input, length, locale_charset (), breaks);
+
+ for (i = 0; i < length; i++)
+ {
+ switch (breaks[i])
+ {
+ case UC_BREAK_POSSIBLE:
+ putc ('|', stdout);
+ break;
+ case UC_BREAK_MANDATORY:
+ break;
+ case UC_BREAK_PROHIBITED:
+ break;
+ default:
+ abort ();
+ }
+ putc (input[i], stdout);
+ }
+
+ free (breaks);
+
+ return 0;
+ }
+ else
+ return 1;
+}
+
+#endif /* TEST */