compiler/clib/vsnprintf.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     C function vsnprintf().
   6 */
   7 /* Original source from libnix */
   8
   9 #include <stdio.h>
  10
  11 struct data
  12 {
  13     char * str;
  14     size_t n;
  15 };
  16
  17 static int _vsnprintf_uc (int c, struct data * data)
  18 {
  19     if (data->n)
  20     {
  21         *(data->str) ++ = c;
  22         data->n --;
  23     }
  24
  25     return 1;
  26 }
  27
  28 /*****************************************************************************
  29
  30     NAME */
  31         #include <stdio.h>
  32 #include <stdarg.h>
  33
  34         int vsnprintf (
  35
  36 /*  SYNOPSIS */
  37         char       * str,
  38         size_t       n,
  39         const char * format,
  40         va_list      args)
  41
  42 /*  FUNCTION
  43         Format a list of arguments and put them into the string str.
  44         The function makes sure that no more than n characters (including
  45         the terminal 0 byte) are written into str.
  46
  47     INPUTS
  48         str - The formatted result is stored here
  49         n - The size of str
  50         format - A printf() format string.
  51         args - A list of arguments for the format string.
  52
  53     RESULT
  54         The number of characters written into the string. The 0 byte at the
  55         end is not included. If this is greater than or equal to n then
  56         there was not enough room to write all characters. In this case the
  57         output string is not null-terminated, and the return value is the
  58         number of characters which would have been written if enough space had
  59         been available.
  60
  61     NOTES
  62
  63     EXAMPLE
  64
  65     BUGS
  66
  67     SEE ALSO
  68         printf(), sprintf(), fprintf(), vprintf(), vfprintf(), snprintf(),
  69         vsnprintf()
  70
  71     INTERNALS
  72
  73 ******************************************************************************/
  74 {
  75     int rc;
  76     struct data data;
  77
  78     data.n = n;
  79     data.str = str;
  80
  81     rc = __vcformat (&data, (void *)_vsnprintf_uc, format, args);
  82
  83     if (data.n)
  84     {
  85         *(data.str) = 0;
  86     }
  87
  88     return rc;
  89 } /* vsnprintf */