| /* $OpenBSD: vasprintf.c,v 1.23 2019/01/25 00:19:25 millert Exp $ */ |
| |
| /* |
| * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org> |
| * |
| * 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 <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <unistd.h> |
| #include "local.h" |
| |
| #define INITIAL_SIZE 128 |
| |
| int |
| vasprintf(char **str, const char *fmt, __va_list ap) |
| { |
| int ret; |
| FILE f; |
| struct __sfileext fext; |
| const int pgsz = getpagesize(); |
| |
| _FILEEXT_SETUP(&f, &fext); |
| f._file = -1; |
| f._flags = __SWR | __SSTR | __SALC; |
| f._bf._base = f._p = malloc(INITIAL_SIZE); |
| if (f._bf._base == NULL) |
| goto err; |
| f._bf._size = f._w = INITIAL_SIZE - 1; /* leave room for the NUL */ |
| ret = __vfprintf(&f, fmt, ap); |
| if (ret == -1) |
| goto err; |
| *f._p = '\0'; |
| if (ret + 1 > INITIAL_SIZE && ret + 1 < pgsz / 2) { |
| /* midsize allocations can try to conserve memory */ |
| unsigned char *_base = recallocarray(f._bf._base, |
| f._bf._size + 1, ret + 1, 1); |
| |
| if (_base == NULL) |
| goto err; |
| *str = (char *)_base; |
| } else |
| *str = (char *)f._bf._base; |
| return (ret); |
| |
| err: |
| free(f._bf._base); |
| f._bf._base = NULL; |
| *str = NULL; |
| errno = ENOMEM; |
| return (-1); |
| } |
| DEF_WEAK(vasprintf); |