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-rw-r--r--lib/vsnprintf.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/lib/vsnprintf.c b/lib/vsnprintf.c
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+++ b/lib/vsnprintf.c
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+/* Formatted output to strings.
+ Copyright (C) 2004, 2006-2023 Free Software Foundation, Inc.
+ Written by Simon Josefsson and Yoann Vandoorselaere <yoann@prelude-ids.org>.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+/* Specification. */
+#include <stdio.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vasnprintf.h"
+
+/* Print formatted output to string STR. Similar to vsprintf, but
+ additional length SIZE limit how much is written into STR. Returns
+ string length of formatted string (which may be larger than SIZE).
+ STR may be NULL, in which case nothing will be written. On error,
+ return a negative value. */
+int
+vsnprintf (char *str, size_t size, const char *format, va_list args)
+{
+ char *output;
+ size_t len;
+ size_t lenbuf = size;
+
+ output = vasnprintf (str, &lenbuf, format, args);
+ len = lenbuf;
+
+ if (!output)
+ return -1;
+
+ if (output != str)
+ {
+ if (size)
+ {
+ size_t pruned_len = (len < size ? len : size - 1);
+ memcpy (str, output, pruned_len);
+ str[pruned_len] = '\0';
+ }
+
+ free (output);
+ }
+
+ if (len > INT_MAX)
+ {
+ errno = EOVERFLOW;
+ return -1;
+ }
+
+ return len;
+}