gen/getbsize.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1991, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  */
  54
  55
  56 #include <err.h>
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60
  61 char *
  62 getbsize(headerlenp, blocksizep)
  63         int *headerlenp;
  64         long *blocksizep;
  65 {
  66         static char header[20];
  67         long n, max, mul, blocksize;
  68         char *ep, *p, *form;
  69
  70 #define KB      (1024L)
  71 #define MB      (1024L * 1024L)
  72 #define GB      (1024L * 1024L * 1024L)
  73 #define MAXB    GB              /* No tera, peta, nor exa. */
  74         form = "";
  75         if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
  76                 if ((n = strtol(p, &ep, 10)) < 0)
  77                         goto underflow;
  78                 if (n == 0)
  79                         n = 1;
  80                 if (*ep && ep[1])
  81                         goto fmterr;
  82                 switch (*ep) {
  83                 case 'G': case 'g':
  84                         form = "G";
  85                         max = MAXB / GB;
  86                         mul = GB;
  87                         break;
  88                 case 'K': case 'k':
  89                         form = "K";
  90                         max = MAXB / KB;
  91                         mul = KB;
  92                         break;
  93                 case 'M': case 'm':
  94                         form = "M";
  95                         max = MAXB / MB;
  96                         mul = MB;
  97                         break;
  98                 case '\0':
  99                         max = MAXB;
 100                         mul = 1;
 101                         break;
 102                 default:
 103 fmterr:                 warnx("%s: unknown blocksize", p);
 104                         n = 512;
 105                         mul = 1;
 106                         break;
 107                 }
 108                 if (n > max) {
 109                         warnx("maximum blocksize is %dG", MAXB / GB);
 110                         n = max;
 111                 }
 112                 if ((blocksize = n * mul) < 512) {
 113 underflow:              warnx("minimum blocksize is 512");
 114                         form = "";
 115                         blocksize = n = 512;
 116                 }
 117         } else
 118                 blocksize = n = 512;
 119
 120         (void)snprintf(header, sizeof(header), "%d%s-blocks", n, form);
 121         *headerlenp = strlen(header);
 122         *blocksizep = blocksize;
 123         return (header);
 124 }