Initial revision

lib/unicodeio.c

@@ -0,0 +1,224 @@
+/* Unicode character output to streams with locale dependent encoding.
+
+   Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Library General Public License as published
+   by the Free Software Foundation; either version 2, 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+   USA.  */
+
+/* Written by Bruno Haible <haible@clisp.cons.org>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#if HAVE_STDDEF_H
+# include <stddef.h>
+#endif
+
+#include <stdio.h>
+#if HAVE_STRING_H
+# include <string.h>
+#else
+# include <strings.h>
+#endif
+
+#include <errno.h>
+#ifndef errno
+extern int errno;
+#endif
+
+#if HAVE_ICONV
+# include <iconv.h>
+#endif
+
+#include <error.h>
+
+#if ENABLE_NLS
+# include <libintl.h>
+# define _(Text) gettext (Text)
+#else
+# define _(Text) Text
+#endif
+
+#include "unicodeio.h"
+
+/* When we pass a Unicode character to iconv(), we must pass it in a
+   suitable encoding. 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.  */
+
+/* Stores the UTF-8 representation of the Unicode character wc in r[0..5].
+   Returns the number of bytes stored, or -1 if wc is out of range.  */
+static int
+utf8_wctomb (unsigned char *r, unsigned int wc)
+{
+  int count;
+
+  if (wc < 0x80)
+    count = 1;
+  else if (wc < 0x800)
+    count = 2;
+  else if (wc < 0x10000)
+    count = 3;
+  else if (wc < 0x200000)
+    count = 4;
+  else if (wc < 0x4000000)
+    count = 5;
+  else if (wc <= 0x7fffffff)
+    count = 6;
+  else
+    return -1;
+
+  switch (count)
+    {
+      /* Note: code falls through cases! */
+      case 6: r[5] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x4000000;
+      case 5: r[4] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x200000;
+      case 4: r[3] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x10000;
+      case 3: r[2] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x800;
+      case 2: r[1] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0xc0;
+      case 1: r[0] = wc;
+    }
+
+  return count;
+}
+
+/* Luckily, the encoding's name is platform independent.  */
+#define UTF8_NAME "UTF-8"
+
+/* Converts the Unicode character CODE to its multibyte representation
+   in the current locale and calls the CALLBACK on the resulting byte
+   sequence.
+   Assumes that the locale doesn't change between two calls.  */
+void
+unicode_to_mb (unsigned int code,
+	       void (*callback) PARAMS((const char *buf, size_t buflen,
+					void *callback_arg)),
+	       void *callback_arg)
+{
+  static int initialized;
+  static int is_utf8;
+#if HAVE_ICONV
+  static iconv_t utf8_to_local;
+#endif
+
+  char inbuf[6];
+  int count;
+
+  if (!initialized)
+    {
+      extern const char *locale_charset PARAMS ((void));
+      const char *charset = locale_charset ();
+
+      is_utf8 = !strcmp (charset, UTF8_NAME);
+#if HAVE_ICONV
+      if (!is_utf8)
+	{
+	  utf8_to_local = iconv_open (charset, UTF8_NAME);
+	  if (utf8_to_local == (iconv_t)(-1))
+	    {
+	      /* For an unknown encoding, assume ASCII.  */
+	      utf8_to_local = iconv_open ("ASCII", UTF8_NAME);
+	      if (utf8_to_local == (iconv_t)(-1))
+		error (1, 0,
+		       _("cannot convert U+%04X to local character set: iconv function not usable"),
+		       code);
+	    }
+	}
+#endif
+      initialized = 1;
+    }
+
+  /* Convert the character to UTF-8.  */
+  count = utf8_wctomb ((unsigned char *) inbuf, code);
+  if (count < 0)
+    error (1, 0, _("U+%04X: character out of range"), code);
+
+  if (is_utf8)
+    {
+      callback (inbuf, count, callback_arg);
+    }
+  else
+    {
+#if HAVE_ICONV
+      char outbuf[25];
+      const char *inptr;
+      size_t inbytesleft;
+      char *outptr;
+      size_t outbytesleft;
+      size_t res;
+
+      inptr = inbuf;
+      inbytesleft = count;
+      outptr = outbuf;
+      outbytesleft = sizeof (outbuf);
+
+      /* Convert the character from UTF-8 to the locale's charset.  */
+      res = iconv (utf8_to_local,
+		   (ICONV_CONST char **)&inptr, &inbytesleft,
+		   &outptr, &outbytesleft);
+      if (inbytesleft > 0 || res == (size_t)(-1)
+	  /* Irix iconv() inserts a NUL byte if it cannot convert. */
+# if !defined _LIBICONV_VERSION && (defined sgi || defined __sgi)
+	  || (res > 0 && code != 0 && outptr - outbuf == 1 && *outbuf == '\0')
+# endif
+         )
+	error (1, res == (size_t)(-1) ? errno : 0,
+	       _("cannot convert U+%04X to local character set"), code);
+
+      /* Avoid glibc-2.1 bug and Solaris 2.7 bug.  */
+# if defined _LIBICONV_VERSION \
+    || !((__GLIBC__ - 0 == 2 && __GLIBC_MINOR__ - 0 <= 1) || defined __sun)
+
+      /* Get back to the initial shift state.  */
+      res = iconv (utf8_to_local, NULL, NULL, &outptr, &outbytesleft);
+      if (res == (size_t)(-1))
+	error (1, errno, _("cannot convert U+%04X to local character set"),
+	       code);
+# endif
+
+      callback (outbuf, outptr - outbuf, callback_arg);
+#else
+      error (1, 0,
+	     _("cannot convert U+%04X to local character set: iconv function not available"),
+	     code);
+#endif
+    }
+}
+
+/* Simple callback that outputs the converted string.
+   The STREAM is passed as callback_arg.  */
+static void
+fprintf_callback (const char *buf, size_t buflen, void *callback_arg)
+{
+  FILE *stream = (FILE *) callback_arg;
+
+  fwrite (buf, 1, buflen, stream);
+}
+
+/* Outputs the Unicode character CODE to the output stream STREAM.
+   Assumes that the locale doesn't change between two calls.  */
+void
+print_unicode_char (FILE *stream, unsigned int code)
+{
+  unicode_to_mb (code, fprintf_callback, stream);
+}

lib/unicodeio.h

@@ -0,0 +1,26 @@
+#ifndef UNICODEIO_H
+# define UNICODEIO_H
+
+# include <stdio.h>
+
+# ifndef PARAMS
+#  if defined PROTOTYPES || (defined __STDC__ && __STDC__)
+#   define PARAMS(Args) Args
+#  else
+#   define PARAMS(Args) ()
+#  endif
+# endif
+
+/* Converts the Unicode character CODE to its multibyte representation
+   in the current locale and calls the CALLBACK on the resulting byte
+   sequence.  */
+extern void unicode_to_mb
+	    PARAMS ((unsigned int code,
+		     void (*callback) PARAMS ((const char *buf, size_t buflen,
+					       void *callback_arg)),
+		     void *callback_arg));
+
+/* Outputs the Unicode character CODE to the output stream STREAM.  */
+extern void print_unicode_char PARAMS((FILE *stream, unsigned int code));
+
+#endif