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.\" 34.Dd June 4, 1993 35.Dt CONFSTR 3 36.Os BSD 4 37.Sh NAME 38.Nm confstr 39.Nd get string-valued configurable variables 40.Sh SYNOPSIS 41.Fd #include <unistd.h> 42.Ft size_t 43.Fn confstr "int name" "char *buf" "size_t len" 44.Sh DESCRIPTION 45.Bf -symbolic 46This interface is obsoleted by sysctl(3). 47.Ef 48.Pp 49The 50.Fn confstr 51function provides a method for applications to get configuration 52defined string values. 53.Pp 54The 55.Fa name 56argument specifies the system variable to be queried. 57Symbolic constants for each name value are found in the include file 58.Li <unistd.h> . 59The 60.Fa len 61argument specifies the size of the buffer referenced by the 62argument 63.Fa buf . 64If 65.Fa len 66is non-zero, 67.Fa buf 68is a non-null pointer, and 69.Fa name 70has a value, up to 71.Fa len 72\- 1 bytes of the value are copied into the buffer 73.Fa buf . 74The copied value is always null terminated. 75.Pp 76The available values are as follows: 77.Pp 78.Bl -tag -width "123456" 79.Pp 80.It Li _CS_PATH 81Return a value for the 82.Ev PATH 83environment variable that finds all the standard utilities. 84.El 85.Sh RETURN VALUES 86If the call to 87.Nm confstr 88is not successful, \-1 is returned and 89.Va errno 90is set appropriately. 91Otherwise, if the variable does not have a configuration defined value, 920 is returned and 93.Va errno 94is not modified. 95Otherwise, the buffer size needed to hold the entire configuration-defined 96value is returned. 97If this size is greater than the argument 98.Fa len , 99the string in 100.Fa buf 101was truncated. 102.Sh ERRORS 103The 104.Nm confstr 105function may fail and set 106.Va error 107for any of the errors specified for the library functions 108.Xr malloc 3 109and 110.Xr sysctl 3 . 111.Pp 112In addition, the following errors may be reported: 113.Bl -tag -width Er 114.It Bq Er EINVAL 115The value of the 116.Fa name 117argument is invalid. 118.Sh SEE ALSO 119.Xr sysctl 3 120.Sh HISTORY 121The 122.Nm confstr 123function first appeared in 4.4BSD. 124