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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)getbsize.c  8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/getbsize.c,v 1.7 2002/12/30 19:04:06 obrien Exp $");
  39
  40 #include <err.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44
  45 char *
  46 getbsize(headerlenp, blocksizep)
  47         int *headerlenp;
  48         long *blocksizep;
  49 {
  50         static char header[20];
  51         long n, max, mul, blocksize;
  52         char *ep, *p;
  53         const char *form;
  54
  55 #define KB      (1024L)
  56 #define MB      (1024L * 1024L)
  57 #define GB      (1024L * 1024L * 1024L)
  58 #define MAXB    GB              /* No tera, peta, nor exa. */
  59         form = "";
  60         if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
  61                 if ((n = strtol(p, &ep, 10)) < 0)
  62                         goto underflow;
  63                 if (n == 0)
  64                         n = 1;
  65                 if (*ep && ep[1])
  66                         goto fmterr;
  67                 switch (*ep) {
  68                 case 'G': case 'g':
  69                         form = "G";
  70                         max = MAXB / GB;
  71                         mul = GB;
  72                         break;
  73                 case 'K': case 'k':
  74                         form = "K";
  75                         max = MAXB / KB;
  76                         mul = KB;
  77                         break;
  78                 case 'M': case 'm':
  79                         form = "M";
  80                         max = MAXB / MB;
  81                         mul = MB;
  82                         break;
  83                 case '\0':
  84                         max = MAXB;
  85                         mul = 1;
  86                         break;
  87                 default:
  88 fmterr:                 warnx("%s: unknown blocksize", p);
  89                         n = 512;
  90                         mul = 1;
  91                         break;
  92                 }
  93                 if (n > max) {
  94                         warnx("maximum blocksize is %ldG", MAXB / GB);
  95                         n = max;
  96                 }
  97                 if ((blocksize = n * mul) < 512) {
  98 underflow:              warnx("minimum blocksize is 512");
  99                         form = "";
 100                         blocksize = n = 512;
 101                 }
 102         } else
 103                 blocksize = n = 512;
 104
 105         (void)snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
 106         *headerlenp = strlen(header);
 107         *blocksizep = blocksize;
 108         return (header);
 109 }