getbsize.c revision 330897
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 * 4. 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#if defined(LIBC_SCCS) && !defined(lint) 33static char sccsid[] = "@(#)getbsize.c 8.1 (Berkeley) 6/4/93"; 34#endif /* LIBC_SCCS and not lint */ 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: stable/11/lib/libc/gen/getbsize.c 330897 2018-03-14 03:19:51Z eadler $"); 37 38#include <err.h> 39#include <stdio.h> 40#include <stdlib.h> 41#include <string.h> 42 43char * 44getbsize(int *headerlenp, long *blocksizep) 45{ 46 static char header[20]; 47 long n, max, mul, blocksize; 48 char *ep, *p; 49 const char *form; 50 51#define KB (1024L) 52#define MB (1024L * 1024L) 53#define GB (1024L * 1024L * 1024L) 54#define MAXB GB /* No tera, peta, nor exa. */ 55 form = ""; 56 if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') { 57 if ((n = strtol(p, &ep, 10)) < 0) 58 goto underflow; 59 if (n == 0) 60 n = 1; 61 if (*ep && ep[1]) 62 goto fmterr; 63 switch (*ep) { 64 case 'G': case 'g': 65 form = "G"; 66 max = MAXB / GB; 67 mul = GB; 68 break; 69 case 'K': case 'k': 70 form = "K"; 71 max = MAXB / KB; 72 mul = KB; 73 break; 74 case 'M': case 'm': 75 form = "M"; 76 max = MAXB / MB; 77 mul = MB; 78 break; 79 case '\0': 80 max = MAXB; 81 mul = 1; 82 break; 83 default: 84fmterr: warnx("%s: unknown blocksize", p); 85 n = 512; 86 max = MAXB; 87 mul = 1; 88 break; 89 } 90 if (n > max) { 91 warnx("maximum blocksize is %ldG", 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), "%ld%s-blocks", n, form); 103 *headerlenp = strlen(header); 104 *blocksizep = blocksize; 105 return (header); 106} 107