Rev 2131 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1271 | cejka | 1 | /* |
| 2071 | jermar | 2 | * Copyright (c) 2006 Josef Cejka |
| 1271 | 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 | |||
| 1888 | jermar | 29 | /** @addtogroup generic |
| 1702 | cejka | 30 | * @{ |
| 31 | */ |
||
| 32 | /** @file |
||
| 33 | */ |
||
| 34 | |||
| 1271 | cejka | 35 | #include <print.h> |
| 36 | #include <printf/printf_core.h> |
||
| 37 | #include <memstr.h> |
||
| 38 | |||
| 39 | struct vsnprintf_data { |
||
| 40 | size_t size; /* total space for string */ |
||
| 41 | size_t len; /* count of currently used characters */ |
||
| 42 | char *string; /* destination string */ |
||
| 43 | }; |
||
| 44 | |||
| 45 | /** Write string to given buffer. |
||
| 1288 | jermar | 46 | * Write at most data->size characters including trailing zero. According to C99, snprintf() has to return number |
| 1271 | cejka | 47 | * of characters that would have been written if enough space had been available. Hence the return value is not |
| 1288 | jermar | 48 | * number of really printed characters but size of the input string. Number of really used characters |
| 1271 | cejka | 49 | * is stored in data->len. |
| 50 | * @param str source string to print |
||
| 51 | * @param count size of source string |
||
| 52 | * @param data structure with destination string, counter of used space and total string size. |
||
| 53 | * @return number of characters to print (not characters really printed!) |
||
| 54 | */ |
||
| 2307 | hudecek | 55 | static int vsnprintf_write(const char *str, size_t count, struct vsnprintf_data *data) |
| 1271 | cejka | 56 | { |
| 1604 | cejka | 57 | size_t i; |
| 1271 | cejka | 58 | i = data->size - data->len; |
| 59 | |||
| 1605 | cejka | 60 | if (i == 0) { |
| 61 | return count; |
||
| 1271 | cejka | 62 | } |
| 63 | |||
| 1604 | cejka | 64 | if (i == 1) { |
| 65 | /* We have only one free byte left in buffer => write there trailing zero */ |
||
| 66 | data->string[data->size - 1] = 0; |
||
| 67 | data->len = data->size; |
||
| 1605 | cejka | 68 | return count; |
| 1604 | cejka | 69 | } |
| 70 | |||
| 71 | if (i <= count) { |
||
| 72 | /* We have not enought space for whole string with the trailing zero => print only a part of string */ |
||
| 73 | memcpy((void *)(data->string + data->len), (void *)str, i - 1); |
||
| 74 | data->string[data->size - 1] = 0; |
||
| 75 | data->len = data->size; |
||
| 1605 | cejka | 76 | return count; |
| 1604 | cejka | 77 | } |
| 78 | |||
| 79 | /* Buffer is big enought to print whole string */ |
||
| 80 | memcpy((void *)(data->string + data->len), (void *)str, count); |
||
| 81 | data->len += count; |
||
| 82 | /* Put trailing zero at end, but not count it into data->len so it could be rewritten next time */ |
||
| 83 | data->string[data->len] = 0; |
||
| 84 | |||
| 1271 | cejka | 85 | return count; |
| 86 | } |
||
| 87 | |||
| 88 | int vsnprintf(char *str, size_t size, const char *fmt, va_list ap) |
||
| 89 | { |
||
| 90 | struct vsnprintf_data data = {size, 0, str}; |
||
| 91 | struct printf_spec ps = {(int(*)(void *, size_t, void *))vsnprintf_write, &data}; |
||
| 92 | |||
| 93 | /* Print 0 at end of string - fix the case that nothing will be printed */ |
||
| 94 | if (size > 0) |
||
| 95 | str[0] = 0; |
||
| 96 | |||
| 97 | /* vsnprintf_write ensures that str will be terminated by zero. */ |
||
| 98 | return printf_core(fmt, &ps, ap); |
||
| 99 | } |
||
| 1702 | cejka | 100 | |
| 1888 | jermar | 101 | /** @} |
| 1702 | cejka | 102 | */ |