0,0 → 1,96 |
/* |
* 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 <stdarg.h> |
#include <stdio.h> |
#include <string.h> |
#include <io/printf_core.h> |
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struct vsnprintf_data { |
size_t size; /* total space for string */ |
size_t len; /* count of currently used characters */ |
char *string; /* destination string */ |
}; |
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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 has snprintf 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 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,j; |
i = data->size - data->len; |
j = count; |
|
if (i > 0) { |
if (i <= j) { |
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; |
} else { |
/* 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; |
} |
} else { |
/* Buffer is big enought to print whole string */ |
memcpy((void *)(data->string + data->len), (void *)str, j); |
data->len += j; |
/* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */ |
data->string[data->len] = 0; |
} |
} |
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return count; |
} |
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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}; |
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/* 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); |
} |
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