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Diffstat (limited to 'libmailutils/string/vasnprintf.c')
-rw-r--r--libmailutils/string/vasnprintf.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/libmailutils/string/vasnprintf.c b/libmailutils/string/vasnprintf.c
new file mode 100644
index 000000000..0f4350edb
--- /dev/null
+++ b/libmailutils/string/vasnprintf.c
@@ -0,0 +1,87 @@
+/* GNU Mailutils -- a suite of utilities for electronic mail
+ Copyright (C) 2009, 2010 Free Software Foundation, Inc.
+
+ This library 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 3 of the License, or (at your option) any later version.
+
+ This library 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 library; if not, write to the
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301 USA */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#include <mailutils/io.h>
+
+int
+mu_vasnprintf (char **pbuf, size_t *psize, const char *fmt, va_list ap)
+{
+ char *buf = *pbuf;
+ size_t buflen = *psize;
+ int rc = 0;
+
+ if (!buf)
+ {
+ if (buflen == 0)
+ buflen = 512; /* Initial allocation */
+
+ buf = calloc (1, buflen);
+ if (buf == NULL)
+ return ENOMEM;
+ }
+
+ for (;;)
+ {
+ ssize_t n = vsnprintf (buf, buflen, fmt, ap);
+ if (n < 0 || n >= buflen || !memchr (buf, '\0', n + 1))
+ {
+ char *newbuf;
+ size_t newlen = buflen * 2;
+ if (newlen < buflen)
+ {
+ rc = ENOMEM;
+ break;
+ }
+ newbuf = realloc (buf, newlen);
+ if (newbuf == NULL)
+ {
+ rc = ENOMEM;
+ break;
+ }
+ buflen = newlen;
+ buf = newbuf;
+ }
+ else
+ break;
+ }
+
+ if (rc)
+ {
+ if (!*pbuf)
+ {
+ /* We made first allocation, now free it */
+ free (buf);
+ buf = NULL;
+ buflen = 0;
+ }
+ }
+
+ *pbuf = buf;
+ *psize = buflen;
+ return rc;
+}

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