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         return 1;
  25     }
  26
  27     return EOF;
  28 }
  29
  30 /*****************************************************************************
  31
  32     NAME */
  33         #include <stdio.h>
  34 #include <stdarg.h>
  35
  36         int vsnprintf (
  37
  38 /*  SYNOPSIS */
  39         char       * str,
  40         size_t       n,
  41         const char * format,
  42         va_list      args)
  43
  44 /*  FUNCTION
  45         Format a list of arguments and put them into the string str.
  46         The function makes sure that no more than n characters (including
  47         the terminal 0 byte) are written into str.
  48
  49     INPUTS
  50         str - The formatted result is stored here
  51         n - The size of str
  52         format - A printf() format string.
  53         args - A list of arguments for the format string.
  54
  55     RESULT
  56         The number of characters written or -1 if the string was too small.
  57         In this case, the string is not 0-terminated.
  58
  59     NOTES
  60         No check is beeing made that str is large enough to contain
  61         the result.
  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         return (n - data.n);
  88     }
  89
  90     return -1;
  91 } /* vsnprintf */