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.\" @(#)realpath.3 8.2 (Berkeley) 2/16/94 32.\" 33.Dd May 11, 2012 34.Dt REALPATH 3 35.Os 36.Sh NAME 37.Nm realpath 38.Nd returns the canonicalized absolute pathname 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In stdlib.h 43.Ft "char *" 44.Fn realpath "const char * restrict pathname" "char * restrict resolved_path" 45.Sh DESCRIPTION 46The 47.Fn realpath 48function resolves all symbolic links, extra 49.Dq / 50characters and references to 51.Pa /./ 52and 53.Pa /../ 54in 55.Fa pathname , 56and copies the resulting absolute pathname into 57the memory pointed to by 58.Fa resolved_path . 59The 60.Fa resolved_path 61argument 62.Em must 63point to a buffer capable of storing at least 64.Dv PATH_MAX 65characters, or be 66.Dv NULL . 67.Pp 68The 69.Fn realpath 70function will resolve both absolute and relative paths 71and return the absolute pathname corresponding to 72.Fa pathname . 73All components of 74.Fa pathname 75must exist when 76.Fn realpath 77is called, and all but the last component must name either directories or 78symlinks pointing to the directories. 79.Sh "RETURN VALUES" 80The 81.Fn realpath 82function returns 83.Fa resolved_path 84on success. 85If the function was supplied 86.Dv NULL 87as 88.Fa resolved_path , 89and operation did not cause errors, the returned value is 90a null-terminated string in a buffer allocated by a call to 91.Fn malloc 3 . 92If an error occurs, 93.Fn realpath 94returns 95.Dv NULL , 96and if 97.Fa resolved_path 98is not 99.Dv NULL , 100the array that it points to contains the pathname which caused the problem. 101.Sh ERRORS 102The function 103.Fn realpath 104may fail and set the external variable 105.Va errno 106for any of the errors specified for the library functions 107.Xr lstat 2 , 108.Xr readlink 2 109and 110.Xr getcwd 3 . 111.Sh SEE ALSO 112.Xr getcwd 3 113.\" .Sh STANDARDS 114.\" The 115.\" .Fn realpath 116.\" function conforms to 117.\" .St -p1003.1-2001 . 118.Sh HISTORY 119The 120.Fn realpath 121function first appeared in 122.Bx 4.4 . 123.Sh CAVEATS 124This implementation of 125.Fn realpath 126differs slightly from the Solaris implementation. 127The 128.Bx 4.4 129version always returns absolute pathnames, 130whereas the Solaris implementation will, 131under certain circumstances, return a relative 132.Fa resolved_path 133when given a relative 134.Fa pathname . 135