/*
* Copyright (C) 2006 Josef Cejka
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <print.h>
#include <printf/printf_core.h>
#include <memstr.h>
struct vsnprintf_data {
size_t size; /* total space for string */
size_t len; /* count of currently used characters */
char *string; /* destination string */
};
int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data);
/** Write string to given buffer.
* Write at most data->size characters including trailing zero. According to C99, snprintf() has to return number
* of characters that would have been written if enough space had been available. Hence the return value is not
* number of really printed characters but size of the input string. Number of really used characters
* is stored in data->len.
* @param str source string to print
* @param count size of source string
* @param data structure with destination string, counter of used space and total string size.
* @return number of characters to print (not characters really printed!)
*/
int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data)
{
size_t i;
i = data->size - data->len;
if (i == 0) {
return count;
}
if (i == 1) {
/* We have only one free byte left in buffer => write there trailing zero */
data->string[data->size - 1] = 0;
data->len = data->size;
return count;
}
if (i <= count) {
/* We have not enought space for whole string with the trailing zero => print only a part of string */
memcpy((void *)(data
->string
+ data
->len
), (void *)str
, i
- 1); data->string[data->size - 1] = 0;
data->len = data->size;
return count;
}
/* Buffer is big enought to print whole string */
memcpy((void *)(data
->string
+ data
->len
), (void *)str
, count
); data->len += count;
/* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */
data->string[data->len] = 0;
return count;
}
int vsnprintf(char *str, size_t size, const char *fmt, va_list ap)
{
struct vsnprintf_data data = {size, 0, str};
struct printf_spec ps = {(int(*)(void *, size_t, void *))vsnprintf_write, &data};
/* Print 0 at end of string - fix the case that nothing will be printed */
if (size > 0)
str[0] = 0;
/* vsnprintf_write ensures that str will be terminated by zero. */
return printf_core(fmt, &ps, ap);
}