1.\" Copyright (c) 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)getbsize.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD$ 30.\" 31.Dd June 4, 1993 32.Dt GETBSIZE 3 33.Os 34.Sh NAME 35.Nm getbsize 36.Nd get user block size 37.Sh LIBRARY 38.Lb libc 39.Sh SYNOPSIS 40.In stdlib.h 41.Ft char * 42.Fn getbsize "int *headerlenp" "long *blocksizep" 43.Sh DESCRIPTION 44The 45.Fn getbsize 46function determines the user's preferred block size based on the value of the 47.Dq BLOCKSIZE 48environment variable; see 49.Xr environ 7 50for details on its use and format. 51.Pp 52The 53.Fn getbsize 54function returns a pointer to a null-terminated string describing 55the block size, something like 56.Dq 1K-blocks . 57The memory referenced by 58.Fa headerlenp 59is filled in with the length of the string (not including the 60terminating null). 61The memory referenced by 62.Fa blocksizep 63is filled in with block size, in bytes. 64.Pp 65If the user's block size is unreasonable, a warning message is 66written to standard error and the returned information reflects 67a block size of 512 bytes. 68.Sh SEE ALSO 69.Xr df 1 , 70.Xr du 1 , 71.Xr ls 1 , 72.Xr systat 1 , 73.Xr environ 7 74.Sh HISTORY 75The 76.Fn getbsize 77function first appeared in 78.Bx 4.4 . 79