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| Rev | Author | Line No. | Line |
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| 1234 | cejka | 1 | /* |
| 2071 | jermar | 2 | * Copyright (c) 2006 Josef Cejka |
| 1234 | cejka | 3 | * All rights reserved. |
| 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 | |||
| 1866 | jermar | 29 | /** @addtogroup libc |
| 1653 | cejka | 30 | * @{ |
| 31 | */ |
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| 32 | /** @file |
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| 33 | */ |
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| 34 | |||
| 1234 | cejka | 35 | #include <stdarg.h> |
| 36 | #include <stdio.h> |
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| 37 | #include <string.h> |
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| 38 | #include <io/printf_core.h> |
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| 39 | |||
| 40 | struct vsnprintf_data { |
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| 41 | size_t size; /* total space for string */ |
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| 42 | size_t len; /* count of currently used characters */ |
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| 43 | char *string; /* destination string */ |
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| 44 | }; |
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| 45 | |||
| 46 | /** Write string to given buffer. |
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| 47 | * Write at most data->size characters including trailing zero. According to C99 has snprintf to return number |
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| 48 | * of characters that would have been written if enough space had been available. Hence the return value is not |
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| 49 | * number of really printed characters but size of input string. Number of really used characters |
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| 50 | * is stored in data->len. |
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| 51 | * @param str source string to print |
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| 52 | * @param count size of source string |
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| 53 | * @param data structure with destination string, counter of used space and total string size. |
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| 54 | * @return number of characters to print (not characters really printed!) |
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| 55 | */ |
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| 2209 | decky | 56 | static int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data) |
| 1234 | cejka | 57 | { |
| 1617 | cejka | 58 | size_t i; |
| 1234 | cejka | 59 | i = data->size - data->len; |
| 60 | |||
| 1617 | cejka | 61 | if (i == 0) { |
| 62 | return count; |
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| 1234 | cejka | 63 | } |
| 64 | |||
| 1617 | cejka | 65 | if (i == 1) { |
| 66 | /* We have only one free byte left in buffer => write there trailing zero */ |
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| 67 | data->string[data->size - 1] = 0; |
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| 68 | data->len = data->size; |
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| 69 | return count; |
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| 70 | } |
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| 71 | |||
| 72 | if (i <= count) { |
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| 73 | /* We have not enought space for whole string with the trailing zero => print only a part of string */ |
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| 74 | memcpy((void *)(data->string + data->len), (void *)str, i - 1); |
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| 75 | data->string[data->size - 1] = 0; |
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| 76 | data->len = data->size; |
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| 77 | return count; |
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| 78 | } |
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| 79 | |||
| 80 | /* Buffer is big enought to print whole string */ |
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| 81 | memcpy((void *)(data->string + data->len), (void *)str, count); |
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| 82 | data->len += count; |
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| 83 | /* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */ |
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| 84 | data->string[data->len] = 0; |
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| 85 | |||
| 1234 | cejka | 86 | return count; |
| 87 | } |
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| 88 | |||
| 1623 | cejka | 89 | /** Print formatted to the given buffer with limited size. |
| 90 | * @param str buffer |
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| 91 | * @param size buffer size |
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| 92 | * @param fmt format string |
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| 93 | * \see For more details about format string see printf_core. |
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| 94 | */ |
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| 1234 | cejka | 95 | int vsnprintf(char *str, size_t size, const char *fmt, va_list ap) |
| 96 | { |
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| 97 | struct vsnprintf_data data = {size, 0, str}; |
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| 2209 | decky | 98 | struct printf_spec ps = {(int(*)(void *, size_t, void *)) vsnprintf_write, &data}; |
| 1234 | cejka | 99 | |
| 100 | /* Print 0 at end of string - fix the case that nothing will be printed */ |
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| 101 | if (size > 0) |
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| 102 | str[0] = 0; |
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| 103 | |||
| 104 | /* vsnprintf_write ensures that str will be terminated by zero. */ |
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| 105 | return printf_core(fmt, &ps, ap); |
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| 106 | } |
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| 107 | |||
| 1866 | jermar | 108 | /** @} |
| 1653 | cejka | 109 | */ |