xref: /netbsd-src/lib/libc/gen/getbsize.c (revision 4b30c543a0b21e3ba94f2c569e9a82b4fdb2075f)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * 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
35 /*static char sccsid[] = "from: @(#)getbsize.c	5.3 (Berkeley) 3/9/92";*/
36 static char rcsid[] = "$Id: getbsize.c,v 1.1 1993/08/06 17:03:55 mycroft Exp $";
37 #endif /* not lint */
38 
39 #include <stdio.h>
40 #include <stdlib.h>
41 
42 char *
43 getbsize(prog, headerlenp, blocksizep, force)
44 	char *prog;
45 	int *headerlenp;
46 	long *blocksizep;
47 	int force;
48 {
49 	static char header[20];
50 	long n, max, mul, blocksize;
51 	char *ep, *p, *form;
52 
53 #define	KB	(1024L)
54 #define	MB	(1024L * 1024L)
55 #define	GB	(1024L * 1024L * 1024L)
56 #define	MAXB	GB		/* No tera, peta, nor exa. */
57 	form = "";
58 	if (force) {
59 		blocksize = *blocksizep;
60 		if ((blocksize % GB) == 0) {
61 			form = "G";
62 			n = blocksize / GB;
63 		} else if ((blocksize % MB) == 0) {
64 			form = "M";
65 			n = blocksize / MB;
66 		} else if ((blocksize % KB) == 0) {
67 			form = "K";
68 			n = blocksize / KB;
69 		} else {
70 			n = blocksize;
71 		}
72 	} else if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
73 		if ((n = strtol(p, &ep, 10)) < 0)
74 			goto underflow;
75 		if (n == 0)
76 			n = 1;
77 		if (*ep && ep[1])
78 			goto fmterr;
79 		switch (*ep) {
80 		case 'G': case 'g':
81 			form = "G";
82 			max = MAXB / GB;
83 			mul = GB;
84 			break;
85 		case 'K': case 'k':
86 			form = "K";
87 			max = MAXB / KB;
88 			mul = KB;
89 			break;
90 		case 'M': case 'm':
91 			form = "M";
92 			max = MAXB / MB;
93 			mul = MB;
94 			break;
95 		case '\0':
96 			max = MAXB;
97 			mul = 1;
98 			break;
99 		default:
100 fmterr:			(void)fprintf(stderr,
101 			    "%s: %s: unknown blocksize\n", prog, p);
102 			n = 512;
103 			mul = 1;
104 			break;
105 		}
106 		if (n > max) {
107 			(void)fprintf(stderr,
108 			    "%s: maximum blocksize is %dG\n", prog, MAXB / GB);
109 			n = max;
110 		}
111 		if ((blocksize = n * mul) < 512) {
112 underflow:		(void)fprintf(stderr,
113 			    "%s: minimum blocksize is 512\n", prog);
114 			form = "";
115 			blocksize = n = 512;
116 		}
117 	} else
118 		blocksize = n = 512;
119 
120 	*headerlenp = snprintf(header, sizeof(header), "%d%s-blocks", n, form);
121 	*blocksizep = blocksize;
122 	return (header);
123 }
124