Rev 3343 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1234 | cejka | 1 | /* |
| 2071 | jermar | 2 | * Copyright (c) 2006 Josef Cejka |
| 1234 | cejka | 3 | * All rights reserved. |
| 4 | * |
||
| 5 | * Redistribution and use in source and binary forms, with or without |
||
| 6 | * modification, are permitted provided that the following conditions |
||
| 7 | * are met: |
||
| 8 | * |
||
| 9 | * - Redistributions of source code must retain the above copyright |
||
| 10 | * notice, this list of conditions and the following disclaimer. |
||
| 11 | * - Redistributions in binary form must reproduce the above copyright |
||
| 12 | * notice, this list of conditions and the following disclaimer in the |
||
| 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 |
||
| 15 | * derived from this software without specific prior written permission. |
||
| 16 | * |
||
| 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 |
||
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
||
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
||
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
||
| 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 |
||
| 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 |
||
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||
| 27 | */ |
||
| 28 | |||
| 1866 | jermar | 29 | /** @addtogroup libc |
| 1653 | cejka | 30 | * @{ |
| 31 | */ |
||
| 32 | /** @file |
||
| 33 | */ |
||
| 34 | |||
| 1234 | cejka | 35 | #include <stdarg.h> |
| 36 | #include <stdio.h> |
||
| 37 | #include <string.h> |
||
| 38 | #include <io/printf_core.h> |
||
| 39 | |||
| 40 | struct vsnprintf_data { |
||
| 3397 | rimsky | 41 | size_t size; /* total space for string */ |
| 42 | size_t len; /* count of currently used characters */ |
||
| 43 | char *string; /* destination string */ |
||
| 1234 | cejka | 44 | }; |
| 45 | |||
| 46 | /** Write string to given buffer. |
||
| 3397 | rimsky | 47 | * Write at most data->size characters including trailing zero. According to C99 |
| 48 | * has snprintf to return number of characters that would have been written if |
||
| 49 | * enough space had been available. Hence the return value is not number of |
||
| 50 | * really printed characters but size of input string. Number of really used |
||
| 51 | * characters is stored in data->len. |
||
| 52 | * |
||
| 53 | * @param str Source string to print. |
||
| 54 | * @param count Size of the source string. |
||
| 55 | * @param data Structure with destination string, counter of used space |
||
| 56 | * and total string size. |
||
| 57 | * @return Number of characters to print (not characters really |
||
| 58 | * printed!) |
||
| 1234 | cejka | 59 | */ |
| 3397 | rimsky | 60 | static int |
| 61 | vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data) |
||
| 1234 | cejka | 62 | { |
| 1617 | cejka | 63 | size_t i; |
| 1234 | cejka | 64 | i = data->size - data->len; |
| 65 | |||
| 1617 | cejka | 66 | if (i == 0) { |
| 67 | return count; |
||
| 1234 | cejka | 68 | } |
| 69 | |||
| 1617 | cejka | 70 | if (i == 1) { |
| 3397 | rimsky | 71 | /* |
| 72 | * We have only one free byte left in buffer => write there |
||
| 73 | * trailing zero. |
||
| 74 | */ |
||
| 1617 | cejka | 75 | data->string[data->size - 1] = 0; |
| 76 | data->len = data->size; |
||
| 77 | return count; |
||
| 78 | } |
||
| 79 | |||
| 80 | if (i <= count) { |
||
| 3397 | rimsky | 81 | /* |
| 82 | * We have not enought space for whole string with the trailing |
||
| 83 | * zero => print only a part of string. |
||
| 84 | */ |
||
| 85 | memcpy((void *)(data->string + data->len), (void *)str, i - 1); |
||
| 86 | data->string[data->size - 1] = 0; |
||
| 87 | data->len = data->size; |
||
| 88 | return count; |
||
| 1617 | cejka | 89 | } |
| 90 | |||
| 91 | /* Buffer is big enought to print whole string */ |
||
| 92 | memcpy((void *)(data->string + data->len), (void *)str, count); |
||
| 93 | data->len += count; |
||
| 3397 | rimsky | 94 | /* |
| 95 | * Put trailing zero at end, but not count it into data->len so it could |
||
| 96 | * be rewritten next time. |
||
| 97 | */ |
||
| 1617 | cejka | 98 | data->string[data->len] = 0; |
| 99 | |||
| 1234 | cejka | 100 | return count; |
| 101 | } |
||
| 102 | |||
| 1623 | cejka | 103 | /** Print formatted to the given buffer with limited size. |
| 3397 | rimsky | 104 | * @param str Buffer. |
| 105 | * @param size Bffer size. |
||
| 106 | * @param fmt Format string. |
||
| 1623 | cejka | 107 | * \see For more details about format string see printf_core. |
| 108 | */ |
||
| 1234 | cejka | 109 | int vsnprintf(char *str, size_t size, const char *fmt, va_list ap) |
| 110 | { |
||
| 111 | struct vsnprintf_data data = {size, 0, str}; |
||
| 3397 | rimsky | 112 | struct printf_spec ps = { |
| 113 | (int(*)(void *, size_t, void *)) vsnprintf_write, |
||
| 114 | &data |
||
| 115 | }; |
||
| 1234 | cejka | 116 | |
| 3397 | rimsky | 117 | /* |
| 118 | * Print 0 at end of string - fix the case that nothing will be printed. |
||
| 119 | */ |
||
| 1234 | cejka | 120 | if (size > 0) |
| 121 | str[0] = 0; |
||
| 122 | |||
| 123 | /* vsnprintf_write ensures that str will be terminated by zero. */ |
||
| 124 | return printf_core(fmt, &ps, ap); |
||
| 125 | } |
||
| 126 | |||
| 1866 | jermar | 127 | /** @} |
| 1653 | cejka | 128 | */ |