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/* This file is part of Smap.
Copyright (C) 2009-2010, 2014 Sergey Poznyakoff
Smap is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Smap 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Smap. If not, see <http://www.gnu.org/licenses/>. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <smap/printf.h>
int
smap_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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