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.\" @(#)confstr.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/gen/confstr.3,v 1.5.2.5 2001/12/14 18:33:50 ru Exp $ 34.\" $DragonFly: src/lib/libc/gen/confstr.3,v 1.2 2003/06/17 04:26:42 dillon Exp $ 35.\" 36.Dd June 4, 1993 37.Dt CONFSTR 3 38.Os 39.Sh NAME 40.Nm confstr 41.Nd get string-valued configurable variables 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In unistd.h 46.Ft size_t 47.Fn confstr "int name" "char *buf" "size_t len" 48.Sh DESCRIPTION 49.Bf -symbolic 50This interface is obsoleted by 51.Xr sysctl 3 . 52.Ef 53.Pp 54The 55.Fn confstr 56function provides a method for applications to get configuration 57defined string values. 58.Pp 59The 60.Fa name 61argument specifies the system variable to be queried. 62Symbolic constants for each name value are found in the include file 63.Aq Pa unistd.h . 64The 65.Fa len 66argument specifies the size of the buffer referenced by the 67argument 68.Fa buf . 69If 70.Fa len 71is non-zero, 72.Fa buf 73is a non-null pointer, and 74.Fa name 75has a value, up to 76.Fa len 77\- 1 bytes of the value are copied into the buffer 78.Fa buf . 79The copied value is always null terminated. 80.Pp 81The available values are as follows: 82.Pp 83.Bl -tag -width 6n 84.Pp 85.It Li _CS_PATH 86Return a value for the 87.Ev PATH 88environment variable that finds all the standard utilities. 89.El 90.Sh RETURN VALUES 91If the call to 92.Fn confstr 93is not successful, \-1 is returned and 94.Va errno 95is set appropriately. 96Otherwise, if the variable does not have a configuration defined value, 970 is returned and 98.Va errno 99is not modified. 100Otherwise, the buffer size needed to hold the entire configuration-defined 101value is returned. 102If this size is greater than the argument 103.Fa len , 104the string in 105.Fa buf 106was truncated. 107.Sh ERRORS 108The 109.Fn confstr 110function may fail and set 111.Va errno 112for any of the errors specified for the library functions 113.Xr malloc 3 114and 115.Xr sysctl 3 . 116.Pp 117In addition, the following errors may be reported: 118.Bl -tag -width Er 119.It Bq Er EINVAL 120The value of the 121.Fa name 122argument is invalid. 123.El 124.Sh SEE ALSO 125.Xr sysctl 3 126.Sh HISTORY 127The 128.Fn confstr 129function first appeared in 130.Bx 4.4 . 131