gen/FreeBSD/getbsize.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)getbsize.c  8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/getbsize.c,v 1.9 2008/08/04 06:53:13 cperciva Exp $");
  35
  36 #include <err.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 char *
  42 getbsize(headerlenp, blocksizep)
  43         int *headerlenp;
  44         long *blocksizep;
  45 {
  46         static char header[20];
  47         long n, max, mul, blocksize;
  48         char *ep, *p;
  49         const char *form;
  50
  51 #define KB      (1024L)
  52 #define MB      (1024L * 1024L)
  53 #define GB      (1024L * 1024L * 1024L)
  54 #define MAXB    GB              /* No tera, peta, nor exa. */
  55         form = "";
  56         if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
  57                 if ((n = strtol(p, &ep, 10)) < 0)
  58                         goto underflow;
  59                 if (n == 0)
  60                         n = 1;
  61                 if (*ep && ep[1])
  62                         goto fmterr;
  63                 switch (*ep) {
  64                 case 'G': case 'g':
  65                         form = "G";
  66                         max = MAXB / GB;
  67                         mul = GB;
  68                         break;
  69                 case 'K': case 'k':
  70                         form = "K";
  71                         max = MAXB / KB;
  72                         mul = KB;
  73                         break;
  74                 case 'M': case 'm':
  75                         form = "M";
  76                         max = MAXB / MB;
  77                         mul = MB;
  78                         break;
  79                 case '\0':
  80                         max = MAXB;
  81                         mul = 1;
  82                         break;
  83                 default:
  84 fmterr:                 warnx("%s: unknown blocksize", p);
  85                         n = 512;
  86                         max = MAXB;
  87                         mul = 1;
  88                         break;
  89                 }
  90                 if (n > max) {
  91                         warnx("maximum blocksize is %ldG", MAXB / GB);
  92                         n = max;
  93                 }
  94                 if ((blocksize = n * mul) < 512) {
  95 underflow:              warnx("minimum blocksize is 512");
  96                         form = "";
  97                         blocksize = n = 512;
  98                 }
  99         } else
 100                 blocksize = n = 512;
 101
 102         (void)snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
 103         *headerlenp = strlen(header);
 104         *blocksizep = blocksize;
 105         return (header);
 106 }