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| Rev | Author | Line No. | Line |
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| 1234 | cejka | 1 | /* |
| 2 | * Copyright (C) 2006 Josef Cejka |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | #include <stdarg.h> |
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| 30 | #include <stdio.h> |
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| 31 | #include <string.h> |
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| 32 | #include <io/printf_core.h> |
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| 33 | |||
| 34 | |||
| 35 | struct vsnprintf_data { |
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| 36 | size_t size; /* total space for string */ |
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| 37 | size_t len; /* count of currently used characters */ |
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| 38 | char *string; /* destination string */ |
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| 39 | }; |
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| 40 | |||
| 41 | int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data); |
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| 42 | |||
| 43 | /** Write string to given buffer. |
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| 44 | * Write at most data->size characters including trailing zero. According to C99 has snprintf to return number |
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| 45 | * of characters that would have been written if enough space had been available. Hence the return value is not |
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| 46 | * number of really printed characters but size of input string. Number of really used characters |
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| 47 | * is stored in data->len. |
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| 48 | * @param str source string to print |
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| 49 | * @param count size of source string |
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| 50 | * @param data structure with destination string, counter of used space and total string size. |
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| 51 | * @return number of characters to print (not characters really printed!) |
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| 52 | */ |
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| 53 | int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data) |
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| 54 | { |
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| 55 | size_t i,j; |
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| 56 | i = data->size - data->len; |
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| 57 | j = count; |
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| 58 | |||
| 59 | if (i > 0) { |
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| 60 | if (i <= j) { |
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| 61 | if (i == 1) { |
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| 62 | /* We have only one free byte left in buffer => write there trailing zero */ |
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| 63 | data->string[data->size - 1] = 0; |
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| 64 | data->len = data->size; |
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| 65 | } else { |
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| 66 | /* We have not enought space for whole string with the trailing zero => print only a part of string */ |
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| 67 | memcpy((void *)(data->string + data->len), (void *)str, i - 1); |
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| 68 | data->string[data->size - 1] = 0; |
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| 69 | data->len = data->size; |
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| 70 | } |
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| 71 | } else { |
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| 72 | /* Buffer is big enought to print whole string */ |
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| 73 | memcpy((void *)(data->string + data->len), (void *)str, j); |
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| 74 | data->len += j; |
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| 75 | /* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */ |
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| 76 | data->string[data->len] = 0; |
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| 77 | } |
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| 78 | } |
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| 79 | |||
| 80 | return count; |
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| 81 | } |
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| 82 | |||
| 83 | int vsnprintf(char *str, size_t size, const char *fmt, va_list ap) |
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| 84 | { |
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| 85 | struct vsnprintf_data data = {size, 0, str}; |
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| 86 | struct printf_spec ps = {(int(*)(void *, size_t, void *))vsnprintf_write, &data}; |
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| 87 | |||
| 88 | /* Print 0 at end of string - fix the case that nothing will be printed */ |
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| 89 | if (size > 0) |
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| 90 | str[0] = 0; |
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| 91 | |||
| 92 | /* vsnprintf_write ensures that str will be terminated by zero. */ |
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| 93 | return printf_core(fmt, &ps, ap); |
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| 94 | } |
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| 95 | |||
| 96 |