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. 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.\" $OpenBSD: realpath.3,v 1.10 2003/06/02 20:18:38 millert Exp $ 32.\" 33.Dd February 16, 1994 34.Dt REALPATH 3 35.Os 36.Sh NAME 37.Nm realpath 38.Nd returns the canonicalized absolute pathname 39.Sh SYNOPSIS 40.Fd #include <sys/param.h> 41.Fd #include <stdlib.h> 42.Ft "char *" 43.Fn realpath "const char *pathname" "char resolvedname[MAXPATHLEN]" 44.Sh DESCRIPTION 45The 46.Fn realpath 47function resolves all symbolic links, extra 48.Dq / 49characters and references to 50.Pa /./ 51and 52.Pa /../ 53in 54.Fa pathname , 55and copies the resulting absolute pathname into the memory referenced by 56.Fa resolvedname . 57The 58.Fa resolvedname 59argument 60.Em must 61refer to a buffer capable of storing at least 62.Dv MAXPATHLEN 63characters. 64.Pp 65The 66.Fn realpath 67function will resolve both absolute and relative paths 68and return the absolute pathname corresponding to 69.Fa pathname . 70All but the last component of 71.Fa pathname 72must exist when 73.Fn realpath 74is called. 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 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 resolvedname 119when given a relative 120.Fa pathname . 121