getbsize.c revision 1573 
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#ifndef lint
35static char sccsid[] = "@(#)getbsize.c	8.1 (Berkeley) 6/4/93";
36#endif /* not lint */
37
38#include <err.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42
43char *
44getbsize(headerlenp, blocksizep)
45	int *headerlenp;
46	long *blocksizep;
47{
48	static char header[20];
49	long n, max, mul, blocksize;
50	char *ep, *p, *form;
51
52#define	KB	(1024L)
53#define	MB	(1024L * 1024L)
54#define	GB	(1024L * 1024L * 1024L)
55#define	MAXB	GB		/* No tera, peta, nor exa. */
56	form = "";
57	if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
58		if ((n = strtol(p, &ep, 10)) < 0)
59			goto underflow;
60		if (n == 0)
61			n = 1;
62		if (*ep && ep[1])
63			goto fmterr;
64		switch (*ep) {
65		case 'G': case 'g':
66			form = "G";
67			max = MAXB / GB;
68			mul = GB;
69			break;
70		case 'K': case 'k':
71			form = "K";
72			max = MAXB / KB;
73			mul = KB;
74			break;
75		case 'M': case 'm':
76			form = "M";
77			max = MAXB / MB;
78			mul = MB;
79			break;
80		case '\0':
81			max = MAXB;
82			mul = 1;
83			break;
84		default:
85fmterr:			warnx("%s: unknown blocksize", p);
86			n = 512;
87			mul = 1;
88			break;
89		}
90		if (n > max) {
91			warnx("maximum blocksize is %dG", MAXB / GB);
92			n = max;
93		}
94		if ((blocksize = n * mul) < 512) {
95underflow:		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), "%d%s-blocks", n, form);
103	*headerlenp = strlen(header);
104	*blocksizep = blocksize;
105	return (header);
106}
107