1  /* vsprintf with automatic memory allocation.
       2     Copyright (C) 2002-2004, 2007-2021 Free Software Foundation, Inc.
       3  
       4     This file is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU Lesser General Public License as
       6     published by the Free Software Foundation; either version 2.1 of the
       7     License, or (at your option) any later version.
       8  
       9     This file 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 _VASNPRINTF_H
      18  #define _VASNPRINTF_H
      19  
      20  /* Get va_list.  */
      21  #include <stdarg.h>
      22  
      23  /* Get size_t.  */
      24  #include <stddef.h>
      25  
      26  /* Get _GL_ATTRIBUTE_SPEC_PRINTF_STANDARD.  */
      27  #include <stdio.h>
      28  
      29  #ifdef __cplusplus
      30  extern "C" {
      31  #endif
      32  
      33  /* Write formatted output to a string dynamically allocated with malloc().
      34     You can pass a preallocated buffer for the result in RESULTBUF and its
      35     size in *LENGTHP; otherwise you pass RESULTBUF = NULL.
      36     If successful, return the address of the string (this may be = RESULTBUF
      37     if no dynamic memory allocation was necessary) and set *LENGTHP to the
      38     number of resulting bytes, excluding the trailing NUL.  Upon error, set
      39     errno and return NULL.
      40  
      41     When dynamic memory allocation occurs, the preallocated buffer is left
      42     alone (with possibly modified contents).  This makes it possible to use
      43     a statically allocated or stack-allocated buffer, like this:
      44  
      45            char buf[100];
      46            size_t len = sizeof (buf);
      47            char *output = vasnprintf (buf, &len, format, args);
      48            if (output == NULL)
      49              ... error handling ...;
      50            else
      51              {
      52                ... use the output string ...;
      53                if (output != buf)
      54                  free (output);
      55              }
      56    */
      57  #if REPLACE_VASNPRINTF
      58  # define asnprintf rpl_asnprintf
      59  # define vasnprintf rpl_vasnprintf
      60  #endif
      61  extern char * asnprintf (char *restrict resultbuf, size_t *lengthp,
      62                           const char *format, ...)
      63         _GL_ATTRIBUTE_FORMAT ((_GL_ATTRIBUTE_SPEC_PRINTF_STANDARD, 3, 4));
      64  extern char * vasnprintf (char *restrict resultbuf, size_t *lengthp,
      65                            const char *format, va_list args)
      66         _GL_ATTRIBUTE_FORMAT ((_GL_ATTRIBUTE_SPEC_PRINTF_STANDARD, 3, 0));
      67  
      68  #ifdef __cplusplus
      69  }
      70  #endif
      71  
      72  #endif /* _VASNPRINTF_H */