minix/lib/libc/gen/realpath.3
Lionel Sambuc f14fb60209 Libraries updates and cleanup
* Updating common/lib
 * Updating lib/csu
 * Updating lib/libc
 * Updating libexec/ld.elf_so
 * Corrected test on __minix in featuretest to actually follow the
   meaning of the comment.
 * Cleaned up _REENTRANT-related defintions.
 * Disabled -D_REENTRANT for libfetch
 * Removing some unneeded __NBSD_LIBC defines and tests

Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
2013-01-14 11:36:26 +01:00

142 lines
3.7 KiB
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.\" $NetBSD: realpath.3,v 1.14 2012/06/21 21:35:25 wiz Exp $
.\"
.\" 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.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" documentation and/or other materials provided with the distribution.
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.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\"
.\" from: @(#)realpath.3 8.2 (Berkeley) 2/16/94
.\"
.Dd June 21, 2012
.Dt REALPATH 3
.Os
.Sh NAME
.Nm realpath
.Nd returns the canonicalized absolute pathname
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/param.h
.In stdlib.h
.Ft "char *"
.Fn realpath "const char * restrict pathname" "char * restrict resolvedname"
.Sh DESCRIPTION
The
.Fn realpath
function resolves all symbolic links, extra
.Dq /
characters and references to
.Pa /./
and
.Pa /../
in
.Fa pathname ,
and copies the resulting absolute pathname into
the memory referenced by
.Fa resolvedname .
The
.Fa resolvedname
argument
.Em must
refer to a buffer capable of storing at least
.Dv MAXPATHLEN
characters.
.Pp
The
.Fn realpath
function will resolve both absolute and relative paths
and return the absolute pathname corresponding to
.Fa pathname .
.Sh RETURN VALUES
If
.Fa resolvednamed
is
.Dv NULL ,
it will be allocated and the returned pointer can be deallocated using
.Xr free 3 .
The
.Fn realpath
function returns
.Fa resolvedname
on success.
If an error occurs,
.Fn realpath
returns
.Dv NULL ,
and
.Fa resolvedname
was not allocated by
.Nm ,
it will contain 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 chdir 2 ,
.Xr close 2 ,
.Xr fchdir 2 ,
.Xr lstat 2 ,
.Xr malloc 3 ,
.Xr open 2 ,
.Xr readlink 2
and
.Xr getcwd 3 .
.Sh SEE ALSO
.Xr getcwd 3
.Sh STANDARDS
.Fn realpath
first appeared in
.St -xpg4.2
and is part of
.St -p1003.1-2001 .
.Sh HISTORY
The
.Fn realpath
function call first appeared in
.Bx 4.4 .
In
.Nx 7.0
the function was updated to accept a
.Dv NULL
pointer for the
.Fa resolvedname
argument.
.Sh BUGS
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 resolvedname
when given a relative
.Fa pathname .