diff options
Diffstat (limited to 'lib/unicodeio.c')
| -rw-r--r-- | lib/unicodeio.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/lib/unicodeio.c b/lib/unicodeio.c new file mode 100644 index 0000000..ceeff89 --- /dev/null +++ b/lib/unicodeio.c @@ -0,0 +1,257 @@ +/* Unicode character output to streams with locale dependent encoding. + + Copyright (C) 2000-2003, 2005, 2006 Free Software Foundation, Inc. + + 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, 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. */ + +/* Written by Bruno Haible <haible@clisp.cons.org>. */ + +/* Note: This file requires the locale_charset() function. See in + libiconv-1.8/libcharset/INTEGRATE for how to obtain it. */ + +#include <config.h> + +/* Specification. */ +#include "unicodeio.h" + +#include <stdio.h> +#include <string.h> +#include <errno.h> + +#if HAVE_ICONV +# include <iconv.h> +#endif + +#include <error.h> + +#include "gettext.h" +#define _(msgid) gettext (msgid) +#define N_(msgid) msgid + +#ifndef __attribute__ +# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__ +# define __attribute__(x) /* empty */ +# endif +#endif + +#ifndef ATTRIBUTE_UNUSED +# define ATTRIBUTE_UNUSED __attribute__ ((__unused__)) +#endif + +#include "localcharset.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 SUCCESS callback on the resulting + byte sequence. If an error occurs, invokes the FAILURE callback instead, + passing it CODE and an English error string. + Returns whatever the callback returned. + Assumes that the locale doesn't change between two calls. */ +long +unicode_to_mb (unsigned int code, + long (*success) (const char *buf, size_t buflen, + void *callback_arg), + long (*failure) (unsigned int code, const char *msg, + 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) + { + 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); + } +#endif + initialized = 1; + } + + /* Test whether the utf8_to_local converter is available at all. */ + if (!is_utf8) + { +#if HAVE_ICONV + if (utf8_to_local == (iconv_t)(-1)) + return failure (code, N_("iconv function not usable"), callback_arg); +#else + return failure (code, N_("iconv function not available"), callback_arg); +#endif + } + + /* Convert the character to UTF-8. */ + count = utf8_wctomb ((unsigned char *) inbuf, code); + if (count < 0) + return failure (code, N_("character out of range"), callback_arg); + +#if HAVE_ICONV + if (!is_utf8) + { + 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 + ) + return failure (code, NULL, callback_arg); + + /* Avoid glibc-2.1 bug and Solaris 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)) + return failure (code, NULL, callback_arg); +# endif + + return success (outbuf, outptr - outbuf, callback_arg); + } +#endif + + /* At this point, is_utf8 is true, so no conversion is needed. */ + return success (inbuf, count, callback_arg); +} + +/* Simple success callback that outputs the converted string. + The STREAM is passed as callback_arg. */ +long +fwrite_success_callback (const char *buf, size_t buflen, void *callback_arg) +{ + FILE *stream = (FILE *) callback_arg; + + fwrite (buf, 1, buflen, stream); + return 0; +} + +/* Simple failure callback that displays an error and exits. */ +static long +exit_failure_callback (unsigned int code, const char *msg, + void *callback_arg ATTRIBUTE_UNUSED) +{ + if (msg == NULL) + error (1, 0, _("cannot convert U+%04X to local character set"), code); + else + error (1, 0, _("cannot convert U+%04X to local character set: %s"), code, + gettext (msg)); + return -1; +} + +/* Simple failure callback that displays a fallback representation in plain + ASCII, using the same notation as ISO C99 strings. */ +static long +fallback_failure_callback (unsigned int code, const char *msg ATTRIBUTE_UNUSED + , void *callback_arg) +{ + FILE *stream = (FILE *) callback_arg; + + if (code < 0x10000) + fprintf (stream, "\\u%04X", code); + else + fprintf (stream, "\\U%08X", code); + return -1; +} + +/* Outputs the Unicode character CODE to the output stream STREAM. + Upon failure, exit if exit_on_error is true, otherwise output a fallback + notation. */ +void +print_unicode_char (FILE *stream, unsigned int code, int exit_on_error) +{ + unicode_to_mb (code, fwrite_success_callback, + exit_on_error + ? exit_failure_callback + : fallback_failure_callback, + stream); +} |