[apple/libc.git] / gen / FreeBSD / getbsize.3

.\" Copyright (c) 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)getbsize.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd November 16, 2012
.Dt GETBSIZE 3
.Os
.Sh NAME
.Nm getbsize
.Nd get preferred block size
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdlib.h
.Ft char *
.Fn getbsize "int *headerlenp" "long *blocksizep"
.Sh DESCRIPTION
The
.Fn getbsize
function returns a preferred block size for reporting by system utilities
.Xr df 1 ,
.Xr du 1 ,
.Xr ls 1
and
.Xr systat 1 ,
based on the value of the
.Ev BLOCKSIZE
environment variable.
.Ev BLOCKSIZE
may be specified directly in bytes, or in multiples of a kilobyte by
specifying a number followed by ``K'' or ``k'', in multiples of a
megabyte by specifying a number followed by ``M'' or ``m'' or in
multiples of a gigabyte by specifying a number followed by ``G'' or
``g''.
Multiples must be integers.
.Pp
Valid values of
.Ev BLOCKSIZE
are 512 bytes to 1 gigabyte.
Sizes less than 512 bytes are rounded up to 512 bytes, and sizes
greater than 1 GB are rounded down to 1 GB.
In each case
.Fn getbsize
produces a warning message.
.Pp
The
.Fn getbsize
function returns a pointer to a null-terminated string describing
the block size, something like
.Dq 1K-blocks .
The memory referenced by
.Fa headerlenp
is filled in with the length of the string (not including the
terminating null).
The memory referenced by
.Fa blocksizep
is filled in with block size, in bytes.
.Sh SEE ALSO
.Xr df 1 ,
.Xr du 1 ,
.Xr ls 1 ,
.Xr systat 1 ,
.Xr environ 7
.Sh HISTORY
The
.Fn getbsize
function first appeared in
.Bx 4.4 .
Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1993
e9ce8d39 A	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.
e9ce8d39 A	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	.\"
5b2abdfb	28	.\" @(#)getbsize.3 8.1 (Berkeley) 6/4/93
974e3884	29	.\" $FreeBSD$
e9ce8d39	30	.\"
974e3884	31	.Dd November 16, 2012
5b2abdfb	32	.Dt GETBSIZE 3
e9ce8d39 A	33	.Os
e9ce8d39 A	34	.Sh NAME
5b2abdfb	35	.Nm getbsize
974e3884	36	.Nd get preferred block size
e9ce8d39 A	37	.Sh LIBRARY
	38	.Lb libc
	39	.Sh SYNOPSIS
5b2abdfb A	40	.In stdlib.h
	41	.Ft char *
	42	.Fn getbsize "int headerlenp" "long blocksizep"
e9ce8d39 A	43	.Sh DESCRIPTION
e9ce8d39 A	44	The
5b2abdfb	45	.Fn getbsize
974e3884 A	46	function returns a preferred block size for reporting by system utilities
	47	.Xr df 1 ,
	48	.Xr du 1 ,
	49	.Xr ls 1
	50	and
	51	.Xr systat 1 ,
	52	based on the value of the
	53	.Ev BLOCKSIZE
	54	environment variable.
	55	.Ev BLOCKSIZE
	56	may be specified directly in bytes, or in multiples of a kilobyte by
	57	specifying a number followed by ``K'' or ``k'', in multiples of a
	58	megabyte by specifying a number followed by ``M'' or ``m'' or in
	59	multiples of a gigabyte by specifying a number followed by ``G'' or
	60	``g''.
	61	Multiples must be integers.
	62	.Pp
	63	Valid values of
	64	.Ev BLOCKSIZE
	65	are 512 bytes to 1 gigabyte.
	66	Sizes less than 512 bytes are rounded up to 512 bytes, and sizes
	67	greater than 1 GB are rounded down to 1 GB.
	68	In each case
	69	.Fn getbsize
	70	produces a warning message.
5b2abdfb	71	.Pp
e9ce8d39	72	The
5b2abdfb A	73	.Fn getbsize
	74	function returns a pointer to a null-terminated string describing
	75	the block size, something like
	76	.Dq 1K-blocks .
	77	The memory referenced by
	78	.Fa headerlenp
	79	is filled in with the length of the string (not including the
	80	terminating null).
	81	The memory referenced by
	82	.Fa blocksizep
	83	is filled in with block size, in bytes.
e9ce8d39	84	.Sh SEE ALSO
5b2abdfb A	85	.Xr df 1 ,
	86	.Xr du 1 ,
	87	.Xr ls 1 ,
	88	.Xr systat 1 ,
	89	.Xr environ 7
e9ce8d39 A	90	.Sh HISTORY
e9ce8d39 A	91	The
5b2abdfb	92	.Fn getbsize
e9ce8d39 A	93	function first appeared in
e9ce8d39 A	94	.Bx 4.4 .