1.\" $NetBSD: realpath.3,v 1.12 2005/08/13 19:53:53 elad 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. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" from: @(#)realpath.3 8.2 (Berkeley) 2/16/94 34.\" 35.Dd August 13, 2005 36.Dt REALPATH 3 37.Os 38.Sh NAME 39.Nm realpath 40.Nd returns the canonicalized absolute pathname 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In sys/param.h 45.In stdlib.h 46.Ft "char *" 47.Fn realpath "const char *pathname" "char resolvedname[MAXPATHLEN]" 48.Sh DESCRIPTION 49The 50.Fn realpath 51function resolves all symbolic links, extra 52.Dq / 53characters and references to 54.Pa /./ 55and 56.Pa /../ 57in 58.Fa pathname , 59and copies the resulting absolute pathname into 60the memory referenced by 61.Fa resolvedname . 62The 63.Fa resolvedname 64argument 65.Em must 66refer to a buffer capable of storing at least 67.Dv MAXPATHLEN 68characters. 69.Pp 70The 71.Fn realpath 72function will resolve both absolute and relative paths 73and return the absolute pathname corresponding to 74.Fa pathname . 75.Sh RETURN VALUES 76The 77.Fn realpath 78function returns 79.Fa resolvedname 80on success. 81If an error occurs, 82.Fn realpath 83returns 84.Dv NULL , 85and 86.Fa resolvedname 87contains the pathname which caused the problem. 88.Sh ERRORS 89The function 90.Fn realpath 91may fail and set the external variable 92.Va errno 93for any of the errors specified for the library functions 94.Xr chdir 2 , 95.Xr close 2 , 96.Xr fchdir 2 , 97.Xr lstat 2 , 98.Xr open 2 , 99.Xr readlink 2 100and 101.Xr getcwd 3 . 102.Sh SEE ALSO 103.Xr getcwd 3 104.Sh HISTORY 105The 106.Fn realpath 107function call first appeared in 108.Bx 4.4 . 109.Sh BUGS 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 resolvedname 119when given a relative 120.Fa pathname . 121