diff options
Diffstat (limited to 'libidn/iconvme.c')
| -rw-r--r-- | libidn/iconvme.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/libidn/iconvme.c b/libidn/iconvme.c new file mode 100644 index 0000000000..cc4dd1daa5 --- /dev/null +++ b/libidn/iconvme.c @@ -0,0 +1,171 @@ +/* Recode strings between character sets, using iconv. + Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. + + 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 2.1, 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, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +/* Get prototype. */ +#include "iconvme.h" + +/* Get malloc. */ +#include <stdlib.h> + +/* Get strcmp. */ +#include <string.h> + +/* Get errno. */ +#include <errno.h> + +#ifdef _LIBC +# define HAVE_ICONV 1 +#else +/* Get strdup. */ +# include "strdup.h" +#endif + +#if HAVE_ICONV +/* Get iconv etc. */ +# include <iconv.h> +/* Get MB_LEN_MAX, CHAR_BIT. */ +# include <limits.h> +#endif + +#ifndef SIZE_MAX +# define SIZE_MAX ((size_t) -1) +#endif + +/* Convert a zero-terminated string STR from the FROM_CODSET code set + to the TO_CODESET code set. The returned string is allocated using + malloc, and must be dellocated by the caller using free. On + failure, NULL is returned and errno holds the error reason. Note + that if TO_CODESET uses \0 for anything but to terminate the + string, the caller of this function may have difficulties finding + out the length of the output string. */ +char * +iconv_string (const char *str, const char *from_codeset, + const char *to_codeset) +{ + char *dest = NULL; +#if HAVE_ICONV + iconv_t cd; + char *outp; + char *p = (char *) str; + size_t inbytes_remaining = strlen (p); + /* Guess the maximum length the output string can have. */ + size_t outbuf_size = inbytes_remaining + 1; + size_t outbytes_remaining; + size_t err; + int have_error = 0; + + /* Use a worst-case output size guess, so long as that wouldn't be + too large for comfort. It's OK if the guess is wrong so long as + it's nonzero. */ + size_t approx_sqrt_SIZE_MAX = SIZE_MAX >> (sizeof (size_t) * CHAR_BIT / 2); + if (outbuf_size <= approx_sqrt_SIZE_MAX / MB_LEN_MAX) + outbuf_size *= MB_LEN_MAX; + outbytes_remaining = outbuf_size - 1; +#endif + + if (strcmp (to_codeset, from_codeset) == 0) + return strdup (str); + +#if HAVE_ICONV + cd = iconv_open (to_codeset, from_codeset); + if (cd == (iconv_t) -1) + return NULL; + + outp = dest = (char *) malloc (outbuf_size); + if (dest == NULL) + goto out; + +again: + err = iconv (cd, &p, &inbytes_remaining, &outp, &outbytes_remaining); + + if (err == (size_t) - 1) + { + switch (errno) + { + case EINVAL: + /* Incomplete text, do not report an error */ + break; + + case E2BIG: + { + size_t used = outp - dest; + size_t newsize = outbuf_size * 2; + char *newdest; + + if (newsize <= outbuf_size) + { + errno = ENOMEM; + have_error = 1; + goto out; + } + newdest = (char *) realloc (dest, newsize); + if (newdest == NULL) + { + have_error = 1; + goto out; + } + dest = newdest; + outbuf_size = newsize; + + outp = dest + used; + outbytes_remaining = outbuf_size - used - 1; /* -1 for NUL */ + + goto again; + } + break; + + case EILSEQ: + have_error = 1; + break; + + default: + have_error = 1; + break; + } + } + + *outp = '\0'; + +out: + { + int save_errno = errno; + + if (iconv_close (cd) < 0 && !have_error) + { + /* If we didn't have a real error before, make sure we restore + the iconv_close error below. */ + save_errno = errno; + have_error = 1; + } + + if (have_error && dest) + { + free (dest); + dest = NULL; + errno = save_errno; + } + } +#else + errno = ENOSYS; +#endif + + return dest; +} |