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