usr/src/cmd/sendmail/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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include <sm/gen.h>
  29 SM_RCSID("@(#)$Id: vasprintf.c,v 1.26.2.1 2003/06/03 02:14:09 ca Exp $")
  30 #include <stdlib.h>
  31 #include <errno.h>
  32 #include <sm/io.h>
  33 #include <sm/heap.h>
  34 #include "local.h"
  35
  36 /*
  37 **  SM_VASPRINTF -- printf to a dynamically allocated string
  38 **
  39 **  Write 'printf' output to a dynamically allocated string
  40 **  buffer which is returned to the caller.
  41 **
  42 **      Parameters:
  43 **              str -- *str receives a pointer to the allocated string
  44 **              fmt -- format directives for printing
  45 **              ap -- variable argument list
  46 **
  47 **      Results:
  48 **              On failure, set *str to NULL, set errno, and return -1.
  49 **
  50 **              On success, set *str to a pointer to a nul-terminated
  51 **              string buffer containing printf output, and return the
  52 **              length of the string (not counting the nul).
  53 */
  54
  55 #define SM_VA_BUFSIZE   128
  56
  57 int
  58 sm_vasprintf(str, fmt, ap)
  59         char **str;
  60         const char *fmt;
  61         SM_VA_LOCAL_DECL
  62 {
  63         int ret;
  64         SM_FILE_T fake;
  65         unsigned char *base;
  66
  67         fake.sm_magic = SmFileMagic;
  68         fake.f_timeout = SM_TIME_FOREVER;
  69         fake.f_timeoutstate = SM_TIME_BLOCK;
  70         fake.f_file = -1;
  71         fake.f_flags = SMWR | SMSTR | SMALC;
  72         fake.f_bf.smb_base = fake.f_p = (unsigned char *)sm_malloc(SM_VA_BUFSIZE);
  73         if (fake.f_bf.smb_base == NULL)
  74                 goto err2;
  75         fake.f_close = NULL;
  76         fake.f_open = NULL;
  77         fake.f_read = NULL;
  78         fake.f_write = NULL;
  79         fake.f_seek = NULL;
  80         fake.f_setinfo = fake.f_getinfo = NULL;
  81         fake.f_type = "sm_vasprintf:fake";
  82         fake.f_bf.smb_size = fake.f_w = SM_VA_BUFSIZE - 1;
  83         fake.f_timeout = SM_TIME_FOREVER;
  84         ret = sm_io_vfprintf(&fake, SM_TIME_FOREVER, fmt, ap);
  85         if (ret == -1)
  86                 goto err;
  87         *fake.f_p = '\0';
  88
  89         /* use no more space than necessary */
  90         base = (unsigned char *) sm_realloc(fake.f_bf.smb_base, ret + 1);
  91         if (base == NULL)
  92                 goto err;
  93         *str = (char *)base;
  94         return ret;
  95
  96 err:
  97         if (fake.f_bf.smb_base != NULL)
  98         {
  99                 sm_free(fake.f_bf.smb_base);
 100                 fake.f_bf.smb_base = NULL;
 101         }
 102 err2:
 103         *str = NULL;
 104         errno = ENOMEM;
 105         return -1;
 106 }