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.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)getbsize.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd June 4, 1993 36.Dt GETBSIZE 3 37.Os 38.Sh NAME 39.Nm getbsize 40.Nd get user block size 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In stdlib.h 45.Ft char * 46.Fn getbsize "int *headerlenp" "long *blocksizep" 47.Sh DESCRIPTION 48The 49.Fn getbsize 50function determines the user's preferred block size based on the value of the 51.Dq BLOCKSIZE 52environment variable; see 53.Xr environ 7 54for details on its use and format. 55.Pp 56The 57.Fn getbsize 58function returns a pointer to a null-terminated string describing 59the block size, something like 60.Dq 1K-blocks . 61The memory referenced by 62.Fa headerlenp 63is filled in with the length of the string (not including the 64terminating null). 65The memory referenced by 66.Fa blocksizep 67is filled in with block size, in bytes. 68.Pp 69If the user's block size is unreasonable, a warning message is 70written to standard error and the returned information reflects 71a block size of 512 bytes. 72.Sh SEE ALSO 73.Xr df 1 , 74.Xr du 1 , 75.Xr ls 1 , 76.Xr systat 1 , 77.Xr environ 7 78.Sh HISTORY 79The 80.Fn getbsize 81function first appeared in 82.Bx 4.4 . 83