1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 <err.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36
37 char *
getbsize(int * headerlenp,long * blocksizep)38 getbsize(int *headerlenp, long *blocksizep)
39 {
40 static char header[20];
41 long n, max, mul, blocksize;
42 char *ep, *p;
43 const char *form;
44
45 #define KB (1024L)
46 #define MB (1024L * 1024L)
47 #define GB (1024L * 1024L * 1024L)
48 #define MAXB GB /* No tera, peta, nor exa. */
49 form = "";
50 if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
51 if ((n = strtol(p, &ep, 10)) < 0)
52 goto underflow;
53 if (n == 0)
54 n = 1;
55 if (*ep && ep[1])
56 goto fmterr;
57 switch (*ep) {
58 case 'G': case 'g':
59 form = "G";
60 max = MAXB / GB;
61 mul = GB;
62 break;
63 case 'K': case 'k':
64 form = "K";
65 max = MAXB / KB;
66 mul = KB;
67 break;
68 case 'M': case 'm':
69 form = "M";
70 max = MAXB / MB;
71 mul = MB;
72 break;
73 case '\0':
74 max = MAXB;
75 mul = 1;
76 break;
77 default:
78 fmterr: warnx("%s: unknown blocksize", p);
79 n = 512;
80 max = MAXB;
81 mul = 1;
82 break;
83 }
84 if (n > max) {
85 warnx("maximum blocksize is %ldG", MAXB / GB);
86 n = max;
87 }
88 if ((blocksize = n * mul) < 512) {
89 underflow: warnx("minimum blocksize is 512");
90 form = "";
91 blocksize = n = 512;
92 }
93 } else
94 blocksize = n = 512;
95
96 (void)snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
97 *headerlenp = strlen(header);
98 *blocksizep = blocksize;
99 return (header);
100 }
101