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.\" 37.Dd "February 16, 1994" 38.Dt REALPATH 3 39.Os 40.Sh NAME 41.Nm realpath 42.Nd returns the canonicalized absolute pathname 43.Sh SYNOPSIS 44.Fd #include <sys/param.h> 45.Fd #include <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 . 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_name 85on success. 86If an error occurs, 87.Fn realpath 88returns 89.Dv NULL , 90and 91.Fa resolved_name 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 chdir 2 , 100.Xr close 2 , 101.Xr fchdir 2 , 102.Xr lstat 2 , 103.Xr open 2 , 104.Xr readlink 2 105and 106.Xr getcwd 3 . 107.Sh CAVEATS 108This implementation of 109.Fn realpath 110differs slightly from the Solaris implementation. 111The 112.Bx 4.4 113version always returns absolute pathnames, 114whereas the Solaris implementation will, 115under certain circumstances, return a relative 116.Fa resolved_path 117when given a relative 118.Fa pathname . 119.Sh "SEE ALSO" 120.Xr getcwd 3 121.Sh HISTORY 122The 123.Fn realpath 124function call first appeared in 125.Bx 4.4 . 126