Bash-4.2 distribution sources and documentation

lib/sh/unicode.c

@@ -0,0 +1,235 @@
+/* unicode.c - functions to convert unicode characters */
+
+/* Copyright (C) 2010 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash 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 3 of the License, or
+   (at your option) any later version.
+
+   Bash 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 Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#if defined (HANDLE_MULTIBYTE)
+
+#include <stdc.h>
+#include <wchar.h>
+#include <bashansi.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <limits.h>
+
+#if HAVE_ICONV
+#  include <iconv.h>
+#endif
+
+#include <xmalloc.h>
+
+#ifndef USHORT_MAX
+#  ifdef USHRT_MAX
+#    define USHORT_MAX USHRT_MAX
+#  else
+#    define USHORT_MAX ((unsigned short) ~(unsigned short)0)
+#  endif
+#endif
+
+#if !defined (STREQ)
+#  define STREQ(a, b) ((a)[0] == (b)[0] && strcmp ((a), (b)) == 0)
+#endif /* !STREQ */
+
+#if defined (HAVE_LOCALE_CHARSET)
+extern const char *locale_charset __P((void));
+#else
+extern char *get_locale_var __P((char *));
+#endif
+
+static int u32init = 0;
+static int utf8locale = 0;
+#if defined (HAVE_ICONV)
+static iconv_t localconv;
+#endif
+
+#ifndef HAVE_LOCALE_CHARSET
+static char *
+stub_charset ()
+{
+  char *locale, *s, *t;
+
+  locale = get_locale_var ("LC_CTYPE");
+  if (locale == 0 || *locale == 0)
+    return "ASCII";
+  s = strrchr (locale, '.');
+  if (s)
+    {
+      t = strchr (s, '@');
+      if (t)
+	*t = 0;
+      return ++s;
+    }
+  else if (STREQ (locale, "UTF-8"))
+    return "UTF-8";
+  else
+    return "ASCII";
+}
+#endif
+
+/* u32toascii ? */
+int
+u32tochar (wc, s)
+     wchar_t wc;
+     char *s;
+{
+  unsigned long x;
+  int l;
+
+  x = wc;
+  l = (x <= UCHAR_MAX) ? 1 : ((x <= USHORT_MAX) ? 2 : 4);
+
+  if (x <= UCHAR_MAX)
+    s[0] = x & 0xFF;
+  else if (x <= USHORT_MAX)	/* assume unsigned short = 16 bits */
+    {
+      s[0] = (x >> 8) & 0xFF;
+      s[1] = x & 0xFF;
+    }
+  else
+    {
+      s[0] = (x >> 24) & 0xFF;
+      s[1] = (x >> 16) & 0xFF;
+      s[2] = (x >> 8) & 0xFF;
+      s[3] = x & 0xFF;
+    }
+  s[l] = '\0';
+  return l;  
+}
+
+int
+u32toutf8 (wc, s)
+     wchar_t wc;
+     char *s;
+{
+  int l;
+
+  l = (wc < 0x0080) ? 1 : ((wc < 0x0800) ? 2 : 3);
+
+  if (wc < 0x0080)
+    s[0] = (unsigned char)wc;
+  else if (wc < 0x0800)
+    {
+      s[0] = (wc >> 6) | 0xc0;
+      s[1] = (wc & 0x3f) | 0x80;
+    }
+  else
+    {
+      s[0] = (wc >> 12) | 0xe0;
+      s[1] = ((wc >> 6) & 0x3f) | 0x80;
+      s[2] = (wc & 0x3f) | 0x80;
+    }
+  s[l] = '\0';
+  return l;
+}
+
+/* convert a single unicode-32 character into a multibyte string and put the
+   result in S, which must be large enough (at least MB_LEN_MAX bytes) */
+int
+u32cconv (c, s)
+     unsigned long c;
+     char *s;
+{
+  wchar_t wc;
+  int n;
+#if HAVE_ICONV
+  const char *charset;
+  char obuf[25], *optr;
+  size_t obytesleft;
+  const char *iptr;
+  size_t sn;
+#endif
+
+  wc = c;
+
+#if __STDC_ISO_10646__
+  if (sizeof (wchar_t) == 4)
+    {
+      n = wctomb (s, wc);
+      return n;
+    }
+#endif
+
+#if HAVE_NL_LANGINFO
+  codeset = nl_langinfo (CODESET);
+  if (STREQ (codeset, "UTF-8"))
+    {
+      n = u32toutf8 (wc, s);
+      return n;
+    }
+#endif
+
+#if HAVE_ICONV
+  /* this is mostly from coreutils-8.5/lib/unicodeio.c */
+  if (u32init == 0)
+    {
+#  if HAVE_LOCALE_CHARSET
+      charset = locale_charset ();	/* XXX - fix later */
+#  else
+      charset = stub_charset ();
+#  endif
+      if (STREQ (charset, "UTF-8"))
+	utf8locale = 1;
+      else
+	{
+	  localconv = iconv_open (charset, "UTF-8");
+	  if (localconv == (iconv_t)-1)
+	    localconv = iconv_open (charset, "ASCII");
+	}
+      u32init = 1;
+    }
+
+  if (utf8locale)
+    {
+      n = u32toutf8 (wc, s);
+      return n;
+    }
+
+  if (localconv == (iconv_t)-1)
+    {
+      n = u32tochar (wc, s);
+      return n;
+    }
+
+  n = u32toutf8 (wc, s);
+
+  optr = obuf;
+  obytesleft = sizeof (obuf);
+  iptr = s;
+  sn = n;
+
+  iconv (localconv, NULL, NULL, NULL, NULL);
+
+  if (iconv (localconv, (ICONV_CONST char **)&iptr, &sn, &optr, &obytesleft) == (size_t)-1)
+    return n;	/* You get utf-8 if iconv fails */
+
+  *optr = '\0';
+
+  /* number of chars to be copied is optr - obuf if we want to do bounds
+     checking */
+  strcpy (s, obuf);
+  return (optr - obuf);
+#endif
+
+  n = u32tochar (wc, s);	/* fallback */
+  return n;
+}
+
+#endif /* HANDLE_MULTIBYTE */