WebSVN – HelenOS – Diff – /trunk/uspace/libc/generic/io/vsnprintf.c


/*
 * 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.
 */
 
/** @addtogroup libc
 * @{
 */
/** @file
 */
 
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <io/printf_core.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 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;
    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;  
}
 
/** Print formatted to the given buffer with limited size.
 * @param str   buffer
 * @param size  buffer size
 * @param fmt   format string
 * \see For more details about format string see printf_core.
 */
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);
}
 
 
 
 
/** @}
 */
 
 
 

Subversion Repositories HelenOS

(root)/trunk/uspace/libc/generic/io/vsnprintf.c @ 2071 – Rev 1787 → 1866

Rev 1787		Rev 1866
1	/*	1	/*
2	* Copyright (C) 2006 Josef Cejka	2	* Copyright (C) 2006 Josef Cejka
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/** @addtogroup libc	29	/** @addtogroup libc
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	*/	33	*/
34		34
35	#include <stdarg.h>	35	#include <stdarg.h>
36	#include <stdio.h>	36	#include <stdio.h>
37	#include <string.h>	37	#include <string.h>
38	#include <io/printf_core.h>	38	#include <io/printf_core.h>
39		39
40		-
41	struct vsnprintf_data {	40	struct vsnprintf_data {
42	size_t size; /* total space for string */	41	size_t size; /* total space for string */
43	size_t len; /* count of currently used characters */	42	size_t len; /* count of currently used characters */
44	char string; / destination string */	43	char string; / destination string */
45	};	44	};
46		45
47	int vsnprintf_write(const char str, size_t count, struct vsnprintf_data data);	46	int vsnprintf_write(const char str, size_t count, struct vsnprintf_data data);
48		47
49	/** Write string to given buffer.	48	/** Write string to given buffer.
50	* Write at most data->size characters including trailing zero. According to C99 has snprintf to return number	49	* Write at most data->size characters including trailing zero. According to C99 has snprintf to return number
51	* of characters that would have been written if enough space had been available. Hence the return value is not	50	* of characters that would have been written if enough space had been available. Hence the return value is not
52	* number of really printed characters but size of input string. Number of really used characters	51	* number of really printed characters but size of input string. Number of really used characters
53	* is stored in data->len.	52	* is stored in data->len.
54	* @param str source string to print	53	* @param str source string to print
55	* @param count size of source string	54	* @param count size of source string
56	* @param data structure with destination string, counter of used space and total string size.	55	* @param data structure with destination string, counter of used space and total string size.
57	* @return number of characters to print (not characters really printed!)	56	* @return number of characters to print (not characters really printed!)
58	*/	57	*/
59	int vsnprintf_write(const char str, size_t count, struct vsnprintf_data data)	58	int vsnprintf_write(const char str, size_t count, struct vsnprintf_data data)
60	{	59	{
61	size_t i;	60	size_t i;
62	i = data->size - data->len;	61	i = data->size - data->len;
63		62
64	if (i == 0) {	63	if (i == 0) {
65	return count;	64	return count;
66	}	65	}
67		66
68	if (i == 1) {	67	if (i == 1) {
69	/* We have only one free byte left in buffer => write there trailing zero */	68	/* We have only one free byte left in buffer => write there trailing zero */
70	data->string[data->size - 1] = 0;	69	data->string[data->size - 1] = 0;
71	data->len = data->size;	70	data->len = data->size;
72	return count;	71	return count;
73	}	72	}
74		73
75	if (i <= count) {	74	if (i <= count) {
76	/* We have not enought space for whole string with the trailing zero => print only a part of string */	75	/* We have not enought space for whole string with the trailing zero => print only a part of string */
77	memcpy((void )(data->string + data->len), (void )str, i - 1);	76	memcpy((void )(data->string + data->len), (void )str, i - 1);
78	data->string[data->size - 1] = 0;	77	data->string[data->size - 1] = 0;
79	data->len = data->size;	78	data->len = data->size;
80	return count;	79	return count;
81	}	80	}
82		81
83	/* Buffer is big enought to print whole string */	82	/* Buffer is big enought to print whole string */
84	memcpy((void )(data->string + data->len), (void )str, count);	83	memcpy((void )(data->string + data->len), (void )str, count);
85	data->len += count;	84	data->len += count;
86	/* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */	85	/* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */
87	data->string[data->len] = 0;	86	data->string[data->len] = 0;
88		87
89	return count;	88	return count;
90	}	89	}
91		90
92	/** Print formatted to the given buffer with limited size.	91	/** Print formatted to the given buffer with limited size.
93	* @param str buffer	92	* @param str buffer
94	* @param size buffer size	93	* @param size buffer size
95	* @param fmt format string	94	* @param fmt format string
96	* \see For more details about format string see printf_core.	95	* \see For more details about format string see printf_core.
97	*/	96	*/
98	int vsnprintf(char str, size_t size, const char fmt, va_list ap)	97	int vsnprintf(char str, size_t size, const char fmt, va_list ap)
99	{	98	{
100	struct vsnprintf_data data = {size, 0, str};	99	struct vsnprintf_data data = {size, 0, str};
101	struct printf_spec ps = {(int()(void , size_t, void *))vsnprintf_write, &data};	100	struct printf_spec ps = {(int()(void , size_t, void *))vsnprintf_write, &data};
102		101
103	/* Print 0 at end of string - fix the case that nothing will be printed */	102	/* Print 0 at end of string - fix the case that nothing will be printed */
104	if (size > 0)	103	if (size > 0)
105	str[0] = 0;	104	str[0] = 0;
106		105
107	/* vsnprintf_write ensures that str will be terminated by zero. */	106	/* vsnprintf_write ensures that str will be terminated by zero. */
108	return printf_core(fmt, &ps, ap);	107	return printf_core(fmt, &ps, ap);
109	}	108	}
110		109
111		-
112		-
113		-
114	/** @}	110	/** @}
115	*/	111	*/
116		-
117		-
118		112