vasprintf.c revision 90792 
1/*
2 * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
3 *      All rights reserved.
4 *
5 * By using this file, you agree to the terms and conditions set
6 * forth in the LICENSE file which can be found at the top level of
7 * the sendmail distribution.
8 */
9
10/*
11 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
12 * All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 *    notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 *    notice, this list of conditions and the following disclaimer in the
21 *    documentation and/or other materials provided with the distribution.
22 * 3. The name of the author may not be used to endorse or promote products
23 *    derived from this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
26 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
28 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
34 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37#include <sm/gen.h>
38SM_RCSID("@(#)$Id: vasprintf.c,v 1.26 2001/09/11 04:04:49 gshapiro Exp $")
39#include <stdlib.h>
40#include <errno.h>
41#include <sm/io.h>
42#include <sm/heap.h>
43#include "local.h"
44
45/*
46**  SM_VASPRINTF -- printf to a dynamically allocated string
47**
48**  Write 'printf' output to a dynamically allocated string
49**  buffer which is returned to the caller.
50**
51**	Parameters:
52**		str -- *str receives a pointer to the allocated string
53**		fmt -- format directives for printing
54**		ap -- variable argument list
55**
56**	Results:
57**		On failure, set *str to NULL, set errno, and return -1.
58**
59**		On success, set *str to a pointer to a nul-terminated
60**		string buffer containing printf output,	and return the
61**		length of the string (not counting the nul).
62*/
63
64#define SM_VA_BUFSIZE	128
65
66int
67sm_vasprintf(str, fmt, ap)
68	char **str;
69	const char *fmt;
70	SM_VA_LOCAL_DECL
71{
72	int ret;
73	SM_FILE_T fake;
74	unsigned char *base;
75
76	fake.sm_magic = SmFileMagic;
77	fake.f_timeout = SM_TIME_FOREVER;
78	fake.f_timeoutstate = SM_TIME_BLOCK;
79	fake.f_file = -1;
80	fake.f_flags = SMWR | SMSTR | SMALC;
81	fake.f_bf.smb_base = fake.f_p = (unsigned char *)sm_malloc(SM_VA_BUFSIZE);
82	if (fake.f_bf.smb_base == NULL)
83		goto err2;
84	fake.f_close = NULL;
85	fake.f_open = NULL;
86	fake.f_read = NULL;
87	fake.f_write = NULL;
88	fake.f_seek = NULL;
89	fake.f_setinfo = fake.f_getinfo = NULL;
90	fake.f_type = "sm_vasprintf:fake";
91	fake.f_bf.smb_size = fake.f_w = SM_VA_BUFSIZE - 1;
92	fake.f_timeout = SM_TIME_FOREVER;
93	ret = sm_io_vfprintf(&fake, SM_TIME_FOREVER, fmt, ap);
94	if (ret == -1)
95		goto err;
96	*fake.f_p = '\0';
97
98	/* use no more space than necessary */
99	base = (unsigned char *) sm_realloc(fake.f_bf.smb_base, ret + 1);
100	if (base == NULL)
101		goto err;
102	*str = (char *)base;
103	return ret;
104
105err:
106	if (fake.f_bf.smb_base != NULL)
107	{
108		sm_free(fake.f_bf.smb_base);
109		fake.f_bf.smb_base = NULL;
110	}
111err2:
112	*str = NULL;
113	errno = ENOMEM;
114	return -1;
115}
116