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c4b681fd | 1 | /* Formatted output to strings. |
f0007cad | 2 | Copyright (C) 2004, 2006-2012 Free Software Foundation, Inc. |
c4b681fd LC |
3 | Written by Simon Josefsson and Yoann Vandoorselaere <yoann@prelude-ids.org>. |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU Lesser General Public License as published by | |
7 | the Free Software Foundation; either version 2, or (at your option) | |
8 | any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public License along | |
16 | with this program; if not, write to the Free Software Foundation, | |
17 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
18 | ||
19 | #ifdef HAVE_CONFIG_H | |
20 | # include <config.h> | |
21 | #endif | |
22 | ||
23 | /* Specification. */ | |
24 | #include <stdio.h> | |
25 | ||
26 | #include <errno.h> | |
27 | #include <limits.h> | |
28 | #include <stdarg.h> | |
29 | #include <stdlib.h> | |
30 | #include <string.h> | |
31 | ||
32 | #include "vasnprintf.h" | |
33 | ||
34 | /* Print formatted output to string STR. Similar to vsprintf, but | |
35 | additional length SIZE limit how much is written into STR. Returns | |
36 | string length of formatted string (which may be larger than SIZE). | |
37 | STR may be NULL, in which case nothing will be written. On error, | |
38 | return a negative value. */ | |
39 | int | |
40 | vsnprintf (char *str, size_t size, const char *format, va_list args) | |
41 | { | |
42 | char *output; | |
43 | size_t len; | |
44 | size_t lenbuf = size; | |
45 | ||
46 | output = vasnprintf (str, &lenbuf, format, args); | |
47 | len = lenbuf; | |
48 | ||
49 | if (!output) | |
50 | return -1; | |
51 | ||
52 | if (output != str) | |
53 | { | |
54 | if (size) | |
1cd4fffc LC |
55 | { |
56 | size_t pruned_len = (len < size ? len : size - 1); | |
57 | memcpy (str, output, pruned_len); | |
58 | str[pruned_len] = '\0'; | |
59 | } | |
c4b681fd LC |
60 | |
61 | free (output); | |
62 | } | |
63 | ||
64 | if (len > INT_MAX) | |
65 | { | |
66 | errno = EOVERFLOW; | |
67 | return -1; | |
68 | } | |
69 | ||
70 | return len; | |
71 | } |