#include <stdarg.h>
#include <sys/types.h>
#include <stdio.h>

#if defined (__SVR4) && defined (__sun)
#include <sys/varargs.h>
#endif

int asprintf(char **ret, const char *fmt, ...) {
	va_list ap;
	int retval;

	va_start(ap, fmt);
	retval = vasprintf(ret, fmt, ap);
	va_end(ap);

	return retval;
}

int vasprintf(char **ret, const char *fmt, va_list ap) {
	char *buf, *new_buf;
	size_t len;
	int retval;

	len = 128;
	buf = malloc(len);
	if (buf == NULL) {
		*ret = NULL;
		return -1;
	}

	retval = vsnprintf(buf, len, fmt, ap);
	if (retval < 0) {
		free(buf);
		*ret = NULL;
		return -1;
	}

	if (retval < len) {
		new_buf = realloc(buf, retval + 1);
		if (new_buf == NULL)
			*ret = buf;
		else
			*ret = new_buf;
		return retval;
	}

	len = (size_t)retval + 1;
	free(buf);
	buf = malloc(len);
	if (buf == NULL) {
		*ret = NULL;
		return -1;
	}
	retval = vsnprintf(buf, len, fmt, ap);
	if (retval != len - 1) {
		free(buf);
		*ret = NULL;
		return -1;
	}
	*ret = buf;
	return retval;
}