1.\" $NetBSD: realpath.3,v 1.3 1997/05/29 01:48:19 cgd Exp $ 2.\" 3.\" Copyright (c) 1994 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Jan-Simon Pendry. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the University of 20.\" California, Berkeley and its contributors. 21.\" 4. Neither the name of the University nor the names of its contributors 22.\" may be used to endorse or promote products derived from this software 23.\" without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35.\" SUCH DAMAGE. 36.\" 37.\" from: @(#)realpath.3 8.2 (Berkeley) 2/16/94 38.\" 39.Dd February 16, 1994 40.Dt REALPATH 3 41.Os 42.Sh NAME 43.Nm realpath 44.Nd returns the canonicalized absolute pathname 45.Sh SYNOPSIS 46.Fd #include <sys/param.h> 47.Fd #include <stdlib.h> 48.Ft "char *" 49.Fn realpath "const char *pathname" "char resolvedname[MAXPATHLEN]" 50.Sh DESCRIPTION 51The 52.Fn realpath 53function resolves all symbolic links, extra 54.Dq / 55characters and references to 56.Pa /./ 57and 58.Pa /../ 59in 60.Fa pathname , 61and copies the resulting absolute pathname into 62the memory referenced by 63.Fa resolvedname . 64The 65.Fa resolvedname 66argument 67.Em must 68refer to a buffer capable of storing at least 69.Dv MAXPATHLEN 70characters. 71.Pp 72The 73.Fn realpath 74function will resolve both absolute and relative paths 75and return the absolute pathname corresponding to 76.Fa pathname . 77All but the last component of 78.Fa pathname 79must exist when 80.Fn realpath 81is called. 82.Sh "RETURN VALUES" 83The 84.Fn realpath 85function returns 86.Fa resolved_name 87on success. 88If an error occurs, 89.Fn realpath 90returns 91.Dv NULL , 92and 93.Fa resolved_name 94contains the pathname which caused the problem. 95.Sh ERRORS 96The function 97.Fn realpath 98may fail and set the external variable 99.Va errno 100for any of the errors specified for the library functions 101.Xr chdir 2 , 102.Xr close 2 , 103.Xr fchdir 2 , 104.Xr lstat 2 , 105.Xr open 2 , 106.Xr readlink 2 107and 108.Xr getcwd 3 . 109.Sh CAVEATS 110This implementation of 111.Fn realpath 112differs slightly from the Solaris implementation. 113The 114.Bx 4.4 115version always returns absolute pathnames, 116whereas the Solaris implementation will, 117under certain circumstances, return a relative 118.Fa resolved_path 119when given a relative 120.Fa pathname . 121.Sh "SEE ALSO" 122.Xr getcwd 3 123.Sh HISTORY 124The 125.Fn realpath 126function call first appeared in 127.Bx 4.4 . 128