.\" Copyright (c) 1994 .\" The Regents of the University of California. All rights reserved. .\" .\" This code is derived from software contributed to Berkeley by .\" Jan-Simon Pendry. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)realpath.3 8.2 (Berkeley) 2/16/94 .\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.13 2003/03/27 20:48:53 fjoe Exp $ .\" .Dd February 16, 1994 .Dt REALPATH 3 .Os .Sh NAME .Nm realpath .Nd returns the canonicalized absolute pathname .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In stdlib.h .Ft "char *" .Fo realpath .Fa "const char *restrict file_name" .Fa "char *restrict resolved_name" .Fc .Sh DESCRIPTION The .Fn realpath function resolves all symbolic links, extra .Dq / characters, and references to .Pa /./ and .Pa /../ in .Fa file_name , and copies the resulting absolute pathname into the memory referenced by .Fa resolved_name . The .Fa resolved_name argument .Em must refer to a buffer capable of storing at least .Dv PATH_MAX characters. .Pp The .Fn realpath function will resolve both absolute and relative paths and return the absolute pathname corresponding to .Fa file_name . All components of .Fa file_name must exist when .Fn realpath is called. .Sh "RETURN VALUES" The .Fn realpath function returns .Fa resolved_name on success. If an error occurs, .Fn realpath returns .Dv NULL and .Fa resolved_name contains the pathname which caused the problem. .Sh ERRORS The function .Fn realpath may fail and set the external variable .Va errno for any of the errors specified for the library functions .Xr lstat 2 , .Xr readlink 2 , and .Xr getcwd 3 . .Sh CAVEATS This implementation of .Fn realpath differs slightly from the Solaris implementation. The .Bx 4.4 version always returns absolute pathnames, whereas the Solaris implementation will, under certain circumstances, return a relative .Fa resolved_name when given a relative .Fa file_name . .Sh LEGACY SYNOPSIS .Fd #include <sys/param.h> .Fd #include <stdlib.h> .Pp The include file .In sys/param.h is necessary. .Sh LEGACY DESCRIPTION In legacy mode, the last component of .Fa file_name does not need to exist when .Fn realpath is called. .Sh "SEE ALSO" .Xr getcwd 3 , .Xr compat 5 .Sh HISTORY The .Fn realpath function first appeared in .Bx 4.4 .