1.\" $NetBSD: confstr.3,v 1.15 2003/08/07 16:42:46 agc Exp $ 2.\" 3.\" Copyright (c) 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)confstr.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd June 4, 1993 33.Dt CONFSTR 3 34.Os 35.Sh NAME 36.Nm confstr 37.Nd get string-valued configurable variables 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In 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 47.Xr sysctl 3 . 48.Ef 49.Pp 50The 51.Fn confstr 52function provides a method for applications to get configuration 53defined string values. 54.Pp 55The 56.Fa name 57argument specifies the system variable to be queried. 58Symbolic constants for each name value are found in the include file 59.Li \*[Lt]unistd.h\*[Gt] . 60The 61.Fa len 62argument specifies the size of the buffer referenced by the 63argument 64.Fa buf . 65If 66.Fa len 67is non-zero, 68.Fa buf 69is a non-null pointer, and 70.Fa name 71has a value, up to 72.Fa len 73\- 1 bytes of the value are copied into the buffer 74.Fa buf . 75The copied value is always null terminated. 76.Pp 77The available values are as follows: 78.Pp 79.Bl -tag -width "123456" 80.Pp 81.It Li _CS_PATH 82Return a value for the 83.Ev PATH 84environment variable that finds all the standard utilities. 85.El 86.Sh RETURN VALUES 87If the call to 88.Nm confstr 89is not successful, ((size_t)-1) is returned and 90.Va errno 91is set appropriately. 92Otherwise, if the variable does not have a configuration defined value, 930 is returned and 94.Va errno 95is not modified. 96Otherwise, the buffer size needed to hold the entire configuration-defined 97value is returned. 98If this size is greater than the argument 99.Fa len , 100the string in 101.Fa buf 102was truncated. 103.Sh ERRORS 104The 105.Nm confstr 106function may fail and set 107.Va error 108for any of the errors specified for the library functions 109.Xr malloc 3 110and 111.Xr sysctl 3 . 112.Pp 113In addition, the following errors may be reported: 114.Bl -tag -width Er 115.It Bq Er EINVAL 116The value of the 117.Fa name 118argument is invalid. 119.El 120.Sh SEE ALSO 121.Xr sysctl 3 122.Sh STANDARDS 123The 124.Nm confstr 125function conforms to 126.St -p1003.2-92 . 127.Sh HISTORY 128The 129.Nm confstr 130function first appeared in 131.Bx 4.4 . 132