1 /* $NetBSD: getbsize.c,v 1.17 2012/06/25 22:32:43 abs Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)getbsize.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: getbsize.c,v 1.17 2012/06/25 22:32:43 abs Exp $");
38 #endif
39 #endif /* not lint */
40
41 #include "namespace.h"
42
43 #include <assert.h>
44 #include <err.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48
49 #ifdef __weak_alias
__weak_alias(getbsize,_getbsize)50 __weak_alias(getbsize,_getbsize)
51 #endif
52
53 char *
54 getbsize(int *headerlenp, long *blocksizep)
55 {
56 static char header[20];
57 long n, max, mul, blocksize;
58 char *ep, *p;
59 const char *form;
60
61 #define KB (1024L)
62 #define MB (1024L * 1024L)
63 #define GB (1024L * 1024L * 1024L)
64 #define MAXB GB /* No tera, peta, nor exa. */
65 form = "";
66 if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
67 if ((n = strtol(p, &ep, 10)) < 0)
68 goto underflow;
69 if (n == 0)
70 n = 1;
71 if (*ep && ep[1])
72 goto fmterr;
73 switch (*ep) {
74 case 'G': case 'g':
75 form = "G";
76 max = MAXB / GB;
77 mul = GB;
78 break;
79 case 'K': case 'k':
80 form = "K";
81 max = MAXB / KB;
82 mul = KB;
83 break;
84 case 'M': case 'm':
85 form = "M";
86 max = MAXB / MB;
87 mul = MB;
88 break;
89 case '\0':
90 max = MAXB;
91 mul = 1;
92 break;
93 default:
94 fmterr: warnx("%s: unknown blocksize", p);
95 n = 512;
96 mul = 1;
97 max = 0;
98 break;
99 }
100 if (n > max) {
101 warnx("maximum blocksize is %ldG", MAXB / GB);
102 n = max;
103 }
104 if ((blocksize = n * mul) < 512) {
105 underflow: warnx("%s: minimum blocksize is 512", p);
106 form = "";
107 blocksize = n = 512;
108 }
109 } else
110 blocksize = n = 512;
111
112 if (headerlenp)
113 *headerlenp =
114 snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
115 if (blocksizep)
116 *blocksizep = blocksize;
117 return (header);
118 }
119