compiler/clib/snprintf.c

   1 /*
   2     Copyright © 1995-2003, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     ANSI C function snprintf().
   6 */
   7
   8 /*****************************************************************************
   9
  10     NAME */
  11 #include <stdio.h>
  12
  13 int snprintf (
  14
  15 /*  SYNOPSIS */
  16     char       * str,
  17     size_t       n,
  18     const char * format,
  19     ...)
  20
  21 /*  FUNCTION
  22     C99 says:The snprintf function is equivalent to fprintf, except that the output is
  23     written into an array (specified by argument s) rather than to a stream. If
  24     n is zero, nothing is written, and s may be a null pointer. Otherwise,
  25     output characters beyond the n-1st are discarded rather than being written
  26     to the array, and a null character is written at the end of the characters
  27     actually written into the array. If copying takes place between objects
  28     that overlap, the behavior is undefined.
  29
  30     INPUTS
  31     str - The formatted string is written into this variable. You
  32           must make sure that it is large enough to contain the
  33           result.
  34     n -   At most n characters are written into the string. This
  35           includes the final 0.
  36     format - Format string as described above
  37     ... - Arguments for the format string
  38
  39     RESULT
  40     The snprintf function returns the number of characters that would have been
  41     written had n been sufficiently large, not counting the terminating null
  42     character, or a negative value if an encoding error occurred. Thus, the
  43     null-terminated output has been completely written if and only if the
  44     returned value is nonnegative and less than n.
  45
  46     NOTES
  47
  48     EXAMPLE
  49
  50     BUGS
  51
  52     SEE ALSO
  53     fprintf(), vprintf(), vfprintf(), snprintf(), vsprintf(),
  54     vsnprintf()
  55
  56     INTERNALS
  57
  58 ******************************************************************************/
  59 {
  60     int     retval;
  61     va_list args;
  62
  63     va_start (args, format);
  64
  65     retval = vsnprintf (str, n, format, args);
  66
  67     va_end (args);
  68
  69     return retval;
  70 } /* snprintf */
  71
  72 #ifdef TEST
  73 #include <stdio.h>
  74
  75 int main (int argc, char ** argv)
  76 {
  77     char buffer[11];
  78     int  rc;
  79
  80     printf ("snprintf test\n");
  81
  82     rc = snprintf (buffer, sizeof (buffer), "%10d", 5);
  83
  84     if (rc < sizeof (buffer))
  85         printf ("rc=%d, buffer=\"%s\"\n", rc, buffer);
  86     else
  87         printf ("rc=%d\n", rc);
  88
  89     rc = snprintf (buffer, sizeof (buffer), "%11d", 5);
  90
  91     if (rc < sizeof (buffer))
  92         printf ("rc=%d, buffer=\"%s\"\n", rc, buffer);
  93     else
  94         printf ("rc=%d\n", rc);
  95
  96     return 0;
  97 } /* main */
  98
  99 #endif /* TEST */