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/*
* Copyright (c) 2004 Darren Tucker.
*
* Based originally on asprintf.c from OpenBSD:
* Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <errno.h>
#include <limits.h> /* for INT_MAX */
#include <stdarg.h>
#include <stdio.h> /* for vsnprintf */
#include <stdlib.h>
#define INIT_SZ 128
int
vasprintf(char **str, const char *fmt, va_list ap)
{
int ret;
va_list ap2;
char *string, *newstr;
size_t len;
if ((string = malloc(INIT_SZ)) == NULL)
goto fail;
va_copy(ap2, ap);
ret = vsnprintf(string, INIT_SZ, fmt, ap2);
va_end(ap2);
if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
*str = string;
} else if (ret == INT_MAX || ret < 0) { /* Bad length */
free(string);
goto fail;
} else { /* bigger than initial, realloc allowing for nul */
len = (size_t)ret + 1;
if ((newstr = realloc(string, len)) == NULL) {
free(string);
goto fail;
}
va_copy(ap2, ap);
ret = vsnprintf(newstr, len, fmt, ap2);
va_end(ap2);
if (ret < 0 || (size_t)ret >= len) { /* failed with realloc'ed string */
free(newstr);
goto fail;
}
*str = newstr;
}
return (ret);
fail:
*str = NULL;
errno = ENOMEM;
return (-1);
}
int asprintf(char **str, const char *fmt, ...)
{
va_list ap;
int ret;
*str = NULL;
va_start(ap, fmt);
ret = vasprintf(str, fmt, ap);
va_end(ap);
return ret;
}
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