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.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)realpath.3 8.2 (Berkeley) 2/16/94 36.\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.7.2.3 2001/12/14 18:33:58 ru Exp $ 37.\" $DragonFly: src/lib/libc/stdlib/realpath.3,v 1.2 2003/06/17 04:26:46 dillon Exp $ 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 LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.In sys/param.h 49.In stdlib.h 50.Ft "char *" 51.Fn realpath "const char *pathname" "char resolved_path[MAXPATHLEN]" 52.Sh DESCRIPTION 53The 54.Fn realpath 55function resolves all symbolic links, extra 56.Dq / 57characters and references to 58.Pa /./ 59and 60.Pa /../ 61in 62.Fa pathname , 63and copies the resulting absolute pathname into 64the memory referenced by 65.Fa resolved_path . 66The 67.Fa resolved_path 68argument 69.Em must 70refer to a buffer capable of storing at least 71.Dv MAXPATHLEN 72characters. 73.Pp 74The 75.Fn realpath 76function will resolve both absolute and relative paths 77and return the absolute pathname corresponding to 78.Fa pathname . 79All but the last component of 80.Fa pathname 81must exist when 82.Fn realpath 83is called. 84.Sh "RETURN VALUES" 85The 86.Fn realpath 87function returns 88.Fa resolved_path 89on success. 90If an error occurs, 91.Fn realpath 92returns 93.Dv NULL , 94and 95.Fa resolved_path 96contains the pathname which caused the problem. 97.Sh ERRORS 98The function 99.Fn realpath 100may fail and set the external variable 101.Va errno 102for any of the errors specified for the library functions 103.Xr chdir 2 , 104.Xr close 2 , 105.Xr fchdir 2 , 106.Xr lstat 2 , 107.Xr open 2 , 108.Xr readlink 2 109and 110.Xr getcwd 3 . 111.Sh CAVEATS 112This implementation of 113.Fn realpath 114differs slightly from the Solaris implementation. 115The 116.Bx 4.4 117version always returns absolute pathnames, 118whereas the Solaris implementation will, 119under certain circumstances, return a relative 120.Fa resolved_path 121when given a relative 122.Fa pathname . 123.Sh "SEE ALSO" 124.Xr getcwd 3 125.Sh HISTORY 126The 127.Fn realpath 128function call first appeared in 129.Bx 4.4 . 130