1 files changed, 72 insertions, 0 deletions
diff --git a/src/share/utf8/charset.h b/src/share/utf8/charset.h
new file mode 100644
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+++ b/src/share/utf8/charset.h
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+/*
+ * Copyright (C) 2001 Edmund Grimley Evans <edmundo@rano.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdlib.h>
+
+/*
+ * These functions are like the C library's mbtowc() and wctomb(),
+ * but instead of depending on the locale they always work in UTF-8,
+ * and they use int instead of wchar_t.
+ */
+
+int utf8_mbtowc(int *pwc, const char *s, size_t n);
+int utf8_wctomb(char *s, int wc);
+
+/*
+ * This is an object-oriented version of mbtowc() and wctomb().
+ * The caller first uses charset_find() to get a pointer to struct
+ * charset, then uses the mbtowc() and wctomb() methods on it.
+ * The function charset_max() gives the maximum length of a
+ * multibyte character in that encoding.
+ * This API is only appropriate for stateless encodings like UTF-8
+ * or ISO-8859-3, but I have no intention of implementing anything
+ * other than UTF-8 and 8-bit encodings.
+ *
+ * MINOR BUG: If there is no memory charset_find() may return 0 and
+ * there is no way to distinguish this case from an unknown encoding.
+ */
+
+struct charset;
+
+struct charset *charset_find(const char *code);
+
+int charset_mbtowc(struct charset *charset, int *pwc, const char *s, size_t n);
+int charset_wctomb(struct charset *charset, char *s, int wc);
+int charset_max(struct charset *charset);
+
+/*
+ * Function to convert a buffer from one encoding to another.
+ * Invalid bytes are replaced by '#', and characters that are
+ * not available in the target encoding are replaced by '?'.
+ * Each of TO and TOLEN may be zero if the result is not wanted.
+ * The input or output may contain null bytes, but the output
+ * buffer is also null-terminated, so it is all right to
+ * use charset_convert(fromcode, tocode, s, strlen(s), &t, 0).
+ *
+ * Return value:
+ *
+ *  -2 : memory allocation failed
+ *  -1 : unknown encoding
+ *   0 : data was converted exactly
+ *   1 : valid data was converted approximately (using '?')
+ *   2 : input was invalid (but still converted, using '#')
+ */
+
+int charset_convert(const char *fromcode, const char *tocode,
+		    const char *from, size_t fromlen,
+		    char **to, size_t *tolen);