1  /* vswprintf with automatic memory allocation.
       2     Copyright (C) 2002-2023 Free Software Foundation, Inc.
       3  
       4     This program is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU Lesser General Public License as published by
       6     the Free Software Foundation; either version 2.1 of the License, or
       7     (at your option) any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #ifndef _VASNWPRINTF_H
      18  #define _VASNWPRINTF_H
      19  
      20  /* Get va_list.  */
      21  #include <stdarg.h>
      22  
      23  /* Get wchar_t, size_t.  */
      24  #include <stddef.h>
      25  
      26  #ifdef __cplusplus
      27  extern "C" {
      28  #endif
      29  
      30  /* Write formatted output to a string dynamically allocated with malloc().
      31     You can pass a preallocated buffer for the result in RESULTBUF and its
      32     size in *LENGTHP; otherwise you pass RESULTBUF = NULL.
      33     If successful, return the address of the string (this may be = RESULTBUF
      34     if no dynamic memory allocation was necessary) and set *LENGTHP to the
      35     number of resulting bytes, excluding the trailing NUL.  Upon error, set
      36     errno and return NULL.
      37  
      38     When dynamic memory allocation occurs, the preallocated buffer is left
      39     alone (with possibly modified contents).  This makes it possible to use
      40     a statically allocated or stack-allocated buffer, like this:
      41  
      42            wchar_t buf[100];
      43            size_t len = sizeof (buf) / sizeof (wchar_t);
      44            wchar_t *output = vasnwprintf (buf, &len, format, args);
      45            if (output == NULL)
      46              ... error handling ...;
      47            else
      48              {
      49                ... use the output string ...;
      50                if (output != buf)
      51                  free (output);
      52              }
      53    */
      54  extern wchar_t * asnwprintf (wchar_t *resultbuf, size_t *lengthp,
      55                               const wchar_t *format, ...);
      56  extern wchar_t * vasnwprintf (wchar_t *resultbuf, size_t *lengthp,
      57                                const wchar_t *format, va_list args);
      58  
      59  #ifdef __cplusplus
      60  }
      61  #endif
      62  
      63  #endif /* _VASNWPRINTF_H */