usr/src/lib/libc/port/i18n/wsscanf.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1986 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include  "lint.h"
  33 #include "file64.h"
  34 #include <stdio.h>
  35 #include <stdarg.h>
  36 #include <stdlib.h>
  37 #include <widec.h>
  38 #include <string.h>
  39 #include "libc.h"
  40 #include "stdiom.h"
  41
  42 /*
  43  *      wsscanf -- this function will read wchar_t characters from
  44  *                  wchar_t string according to the conversion format.
  45  *                  Note that the performance degrades if the intermediate
  46  *                  result of conversion exceeds 1024 bytes due to the
  47  *                  use of malloc() on each call.
  48  *                  We should implement wchar_t version of doscan()
  49  *                  for better performance.
  50  */
  51 #define MAXINSTR        1024
  52
  53 int
  54 wsscanf(wchar_t *string, const char *format, ...)
  55 {
  56         va_list         ap;
  57         size_t          i;
  58         char            stackbuf[MAXINSTR];
  59         char            *tempstring = stackbuf;
  60         size_t          malloced = 0;
  61         int             j;
  62
  63         i = wcstombs(tempstring, string, MAXINSTR);
  64         if (i == (size_t)-1)
  65                 return (-1);
  66
  67         if (i == MAXINSTR) { /* The buffer was too small.  Malloc it. */
  68                 tempstring = malloc(malloced = MB_CUR_MAX*wcslen(string)+1);
  69                 if (tempstring == 0)
  70                         return (-1);
  71                 i = wcstombs(tempstring, string, malloced); /* Try again. */
  72                 if (i == (size_t)-1) {
  73                         free(tempstring);
  74                         return (-1);
  75                 }
  76         }
  77
  78         va_start(ap, format);
  79         j = vsscanf(tempstring, format, ap);
  80         va_end(ap);
  81         if (malloced) free(tempstring);
  82         return (j);
  83 }