firmware/libc/sprintf.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 by Gary Czvitkovicz
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 /*
  23  * Minimal printf and snprintf formatting functions
  24  *
  25  * These support %c %s %d and %x
  26  * Field width and zero-padding flag only
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdarg.h>
  31 #include <stdbool.h>
  32 #include <limits.h>
  33 #include "format.h"
  34
  35 /* ALSA library requires a more advanced snprintf, so let's not
  36    override it in simulator for Linux.  Note that Cygwin requires
  37    our snprintf or it produces garbled output after a while. */
  38
  39 struct for_snprintf {
  40     unsigned char *ptr; /* where to store it */
  41     size_t bytes; /* amount already stored */
  42     size_t max;   /* max amount to store */
  43 };
  44
  45 static int sprfunc(void *ptr, unsigned char letter)
  46 {
  47     struct for_snprintf *pr = (struct for_snprintf *)ptr;
  48     if(pr->bytes < pr->max) {
  49         *pr->ptr = letter;
  50         pr->ptr++;
  51         pr->bytes++;
  52         return true;
  53     }
  54     return false; /* filled buffer */
  55 }
  56
  57
  58 int snprintf(char *buf, size_t size, const char *fmt, ...)
  59 {
  60     va_list ap;
  61     struct for_snprintf pr;
  62
  63     pr.ptr = (unsigned char *)buf;
  64     pr.bytes = 0;
  65     pr.max = size;
  66
  67     va_start(ap, fmt);
  68     format(sprfunc, &pr, fmt, ap);
  69     va_end(ap);
  70
  71     /* make sure it ends with a trailing zero */
  72     pr.ptr[(pr.bytes < pr.max) ? 0 : -1] = '\0';
  73
  74     return pr.bytes;
  75 }
  76
  77 int vsnprintf(char *buf, size_t size, const char *fmt, va_list ap)
  78 {
  79     struct for_snprintf pr;
  80
  81     pr.ptr = (unsigned char *)buf;
  82     pr.bytes = 0;
  83     pr.max = size;
  84
  85     format(sprfunc, &pr, fmt, ap);
  86
  87     /* make sure it ends with a trailing zero */
  88     pr.ptr[(pr.bytes < pr.max) ? 0 : -1] = '\0';
  89
  90     return pr.bytes;
  91 }