1.\" Copyright (c) 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Jan-Simon Pendry. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 4. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)realpath.3 8.2 (Berkeley) 2/16/94 32.\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.14 2007/01/09 00:28:10 imp Exp $ 33.\" $DragonFly: src/lib/libc/stdlib/realpath.3,v 1.2 2003/06/17 04:26:46 dillon Exp $ 34.\" 35.Dd February 16, 1994 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 resolved_path[PATH_MAX]" 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 resolved_path . 62The 63.Fa resolved_path 64argument 65.Em must 66refer to a buffer capable of storing at least 67.Dv PATH_MAX 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 . 75All but the last component of 76.Fa pathname 77must exist when 78.Fn realpath 79is called. 80.Sh "RETURN VALUES" 81The 82.Fn realpath 83function returns 84.Fa resolved_path 85on success. 86If an error occurs, 87.Fn realpath 88returns 89.Dv NULL , 90and 91.Fa resolved_path 92contains the pathname which caused the problem. 93.Sh ERRORS 94The function 95.Fn realpath 96may fail and set the external variable 97.Va errno 98for any of the errors specified for the library functions 99.Xr lstat 2 , 100.Xr readlink 2 101and 102.Xr getcwd 3 . 103.Sh CAVEATS 104This implementation of 105.Fn realpath 106differs slightly from the Solaris implementation. 107The 108.Bx 4.4 109version always returns absolute pathnames, 110whereas the Solaris implementation will, 111under certain circumstances, return a relative 112.Fa resolved_path 113when given a relative 114.Fa pathname . 115.Sh "SEE ALSO" 116.Xr getcwd 3 117.Sh HISTORY 118The 119.Fn realpath 120function first appeared in 121.Bx 4.4 . 122