contrib/sendmail-8.14/libsm/vasprintf.c

   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  *
  13  * Permission to use, copy, modify, and distribute this software for any
  14  * purpose with or without fee is hereby granted, provided that the above
  15  * copyright notice and this permission notice appear in all copies.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
  18  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
  20  * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  21  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  22  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  23  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  24  */
  25
  26 #include <sm/gen.h>
  27 SM_RCSID("@(#)$Id: vasprintf.c,v 1.27 2003/06/03 02:14:24 ca Exp $")
  28 #include <stdlib.h>
  29 #include <errno.h>
  30 #include <sm/io.h>
  31 #include <sm/heap.h>
  32 #include "local.h"
  33
  34 /*
  35 **  SM_VASPRINTF -- printf to a dynamically allocated string
  36 **
  37 **  Write 'printf' output to a dynamically allocated string
  38 **  buffer which is returned to the caller.
  39 **
  40 **      Parameters:
  41 **              str -- *str receives a pointer to the allocated string
  42 **              fmt -- format directives for printing
  43 **              ap -- variable argument list
  44 **
  45 **      Results:
  46 **              On failure, set *str to NULL, set errno, and return -1.
  47 **
  48 **              On success, set *str to a pointer to a nul-terminated
  49 **              string buffer containing printf output, and return the
  50 **              length of the string (not counting the nul).
  51 */
  52
  53 #define SM_VA_BUFSIZE   128
  54
  55 int
  56 sm_vasprintf(str, fmt, ap)
  57         char **str;
  58         const char *fmt;
  59         SM_VA_LOCAL_DECL
  60 {
  61         int ret;
  62         SM_FILE_T fake;
  63         unsigned char *base;
  64
  65         fake.sm_magic = SmFileMagic;
  66         fake.f_timeout = SM_TIME_FOREVER;
  67         fake.f_timeoutstate = SM_TIME_BLOCK;
  68         fake.f_file = -1;
  69         fake.f_flags = SMWR | SMSTR | SMALC;
  70         fake.f_bf.smb_base = fake.f_p = (unsigned char *)sm_malloc(SM_VA_BUFSIZE);
  71         if (fake.f_bf.smb_base == NULL)
  72                 goto err2;
  73         fake.f_close = NULL;
  74         fake.f_open = NULL;
  75         fake.f_read = NULL;
  76         fake.f_write = NULL;
  77         fake.f_seek = NULL;
  78         fake.f_setinfo = fake.f_getinfo = NULL;
  79         fake.f_type = "sm_vasprintf:fake";
  80         fake.f_bf.smb_size = fake.f_w = SM_VA_BUFSIZE - 1;
  81         fake.f_timeout = SM_TIME_FOREVER;
  82         ret = sm_io_vfprintf(&fake, SM_TIME_FOREVER, fmt, ap);
  83         if (ret == -1)
  84                 goto err;
  85         *fake.f_p = '\0';
  86
  87         /* use no more space than necessary */
  88         base = (unsigned char *) sm_realloc(fake.f_bf.smb_base, ret + 1);
  89         if (base == NULL)
  90                 goto err;
  91         *str = (char *)base;
  92         return ret;
  93
  94 err:
  95         if (fake.f_bf.smb_base != NULL)
  96         {
  97                 sm_free(fake.f_bf.smb_base);
  98                 fake.f_bf.smb_base = NULL;
  99         }
 100 err2:
 101         *str = NULL;
 102         errno = ENOMEM;
 103         return -1;
 104 }