mirror of
https://git.hardenedbsd.org/hardenedbsd/HardenedBSD.git
synced 2024-11-26 10:53:39 +01:00
3d265fce43
- skipping paragraph macro: Pp after Sh - sections out of conventional order: Sh EXAMPLES - whitespace at end of input line - normalizing date format
137 lines
3.8 KiB
Groff
137 lines
3.8 KiB
Groff
.\"
|
|
.\" Copyright (c) 1997 Shigio Yamaguchi. All rights reserved.
|
|
.\" Copyright (c) 1999 Tama Communications Corporation. All rights reserved.
|
|
.\"
|
|
.\" 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.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd Dec 15, 1997"
|
|
.Dt ABS2REL 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm abs2rel
|
|
.Nd make a relative path name from an absolute path name
|
|
.Sh SYNOPSIS
|
|
.Ft "char *"
|
|
.Fn abs2rel "const char *path" "const char *base" "char *result" "size_t size"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn abs2rel
|
|
function makes a relative path name from an absolute path name
|
|
.Fa path
|
|
based on a directory
|
|
.Fa base
|
|
and copies the resulting path name into the memory referenced by
|
|
.Fa result .
|
|
The
|
|
.Fa result
|
|
argument must refer to a buffer capable of storing at least
|
|
.Fa size
|
|
characters.
|
|
|
|
The resulting path name may include symbolic links.
|
|
The
|
|
.Fn abs2rel
|
|
function doesn't check whether or not any path exists.
|
|
.Sh "RETURN VALUES"
|
|
The
|
|
.Fn abs2rel
|
|
function returns relative path name on success.
|
|
If an error occurs,
|
|
it returns
|
|
.Dv NULL .
|
|
.Sh ERRORS
|
|
The
|
|
.Fn abs2rel
|
|
function may fail and set the external variable
|
|
.Va errno
|
|
to indicate the error.
|
|
.Bl -tag -width Er
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa base
|
|
directory isn't an absolute path name or the
|
|
.Fa size
|
|
argument is zero.
|
|
.It Bq Er ERANGE
|
|
The
|
|
.Fa size
|
|
argument is greater than zero but smaller than the length of the pathname plus 1.
|
|
.Sh EXAMPLE
|
|
char result[MAXPATHLEN];
|
|
char *path = abs2rel("/usr/src/sys", "/usr/local/lib", result, MAXPATHLEN);
|
|
|
|
yields:
|
|
|
|
path == "../../src/sys"
|
|
|
|
Similarly,
|
|
|
|
path1 = abs2rel("/usr/src/sys", "/usr", result, MAXPATHLEN);
|
|
path2 = abs2rel("/usr/src/sys", "/usr/src/sys", result, MAXPATHLEN);
|
|
|
|
yields:
|
|
|
|
path1 == "src/sys"
|
|
path2 == "."
|
|
|
|
.Sh BUGS
|
|
If the
|
|
.Fa base
|
|
directory includes symbolic links,
|
|
the
|
|
.Fn abs2rel
|
|
function produces the wrong path.
|
|
For example, if '/sys' is a symbolic link to '/usr/src/sys',
|
|
|
|
char *path = abs2rel("/usr/local/lib", "/sys", result, MAXPATHLEN);
|
|
|
|
yields:
|
|
|
|
path == "../usr/local/lib" /* It's wrong!! */
|
|
|
|
You should convert the base directory into a real path in advance.
|
|
.Pp
|
|
|
|
path = abs2rel("/sys/kern", realpath("/sys", resolvedname), result, MAXPATHLEN);
|
|
|
|
yields:
|
|
|
|
path == "../../../sys/kern" /* It's correct but ... */
|
|
|
|
That is correct, but a little redundant.
|
|
If you wish get the simple answer 'kern', do the following.
|
|
|
|
path = abs2rel(realpath("/sys/kern", r1), realpath("/sys", r2),
|
|
result, MAXPATHLEN);
|
|
|
|
The
|
|
.Fn realpath
|
|
function assures correct result, but don't forget that
|
|
.Fn realpath
|
|
requires that all but the last component of the path exist.
|
|
.Sh "SEE ALSO"
|
|
.Xr rel2abs 3
|
|
.Sh AUTHORS
|
|
Shigio Yamaguchi (shigio@tamacom.com)
|