1 /* $OpenBSD: vasprintf.c,v 1.24 2025年08月08日 15:58:53 yasuoka Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19#include <stdio.h> 20#include <stdlib.h> 21#include <string.h> 22#include <errno.h> 23#include <unistd.h> 24#include "local.h" 25 26#define INITIAL_SIZE 128 27 28 int 29 vasprintf(char **str, const char *fmt, __va_list ap) 30{ 31 int ret; 32 FILE f = FILEINIT(__SWR | __SSTR | __SALC); 33 const int pgsz = getpagesize(); 34 35 f._bf._base = f._p = malloc(INITIAL_SIZE); 36 if (f._bf._base == NULL) 37 goto err; 38 f._bf._size = f._w = INITIAL_SIZE - 1; /* leave room for the NUL */ 39 ret = __vfprintf(&f, fmt, ap); 40 if (ret == -1) 41 goto err; 42 *f._p = '0円'; 43 if (ret + 1 > INITIAL_SIZE && ret + 1 < pgsz / 2) { 44 /* midsize allocations can try to conserve memory */ 45 unsigned char *_base = recallocarray(f._bf._base, 46 f._bf._size + 1, ret + 1, 1); 47 48 if (_base == NULL) 49 goto err; 50 *str = (char *)_base; 51 } else 52 *str = (char *)f._bf._base; 53 return (ret); 54 55 err: 56 free(f._bf._base); 57 f._bf._base = NULL; 58 *str = NULL; 59 errno = ENOMEM; 60 return (-1); 61} 62 DEF_WEAK(vasprintf); 63