.TH REALPATH 1 "October 16th, 2011" "Debian" "Debian"
.SH NAME
realpath \- return the canonicalised absolute pathname
.SH SYNOPSIS
.if !'po4a'hide' .B realpath
.if !'po4a'hide' .if !'po4a'hide' .RB [ \-s | \-\-strip ]
.if !'po4a'hide' .RB [ \-z | \-\-zero ]
.I " filename " ...
.br
.if !'po4a'hide' .B realpath
.if !'po4a'hide' .BR  \-\-h | \-\-help
.br
.if !'po4a'hide' .B realpath
.if !'po4a'hide' .BR  \-\-v | \-\-version
.SH "DESCRIPTION"
.B realpath
converts each
.I filename
argument to an absolute pathname, which has no
components that are symbolic links or the special
.B .
or
.B ..
directory entries.
(See
.BR realpath (3)
for more information.)
.br
Each path component in the
.I filename
must exist, otherwise
.B realpath
will fail and non-zero exit status will be returned.
.br
Please note that mostly the same functionality is provided by the `\-e'  option
of the
.BR readlink (1)
command.
.PP
When the
.B \-s
option is used
.B realpath
only removes the
.B .
and
.B ..
directories, but not symbolic links from
.IR filename .
If the given
.I filename
argument is relative (i.e.  does not start with
.RI ` / '),
.B realpath \-s
prepends to it the current directory name as obtained from the
.BR getcwd (2)
system call before further processing.
.PP
Each converted pathname is output to the standard output,
on its own line.
.SH OPTIONS
.TP 5
.if !'po4a'hide' .BR \-s ", "  \-\-strip
Only strip
.B .
and
.BR .. ,
components, but do not resolve symbolic links.
.\"
.TP 5
.if !'po4a'hide' .BR \-z ", " \-\-zero
Separate output filenames with the null character instead of newline,
so it can be used with the
.RI ` \-0 '
option of
.BR xargs (1).
.\"
.TP 5
.if !'po4a'hide' .BR \-h ", " \-\-help
Print short usage information.
.\"
.TP 5
.if !'po4a'hide' .BR \-v ", " \-\-version
Show
.BR realpath 's
version number.
.SH EXAMPLES
.PP
For the examples below let's suppose that
.I /usr/bin/X11
is a symbolic link, pointing to directory
.IR /usr/bin .
.SS Example 1
Regardless of what the current directory is
.br
.RS 4
.nf
.if !'po4a'hide' .BI "realpath " /../usr/bin/X11/./xterm
.fi
.RE
prints
.RS 4
.nf
.if !'po4a'hide' .I /usr/bin/xterm
.fi
.RE
but
.RS 4
.nf
.if !'po4a'hide' .BI "realpath \-s " /../usr/bin/X11/./xterm
.fi
.RE
outputs
.RS 4
.nf
.if !'po4a'hide' .I /usr/bin/X11/xterm
.fi
.RE

.SS Example 2
When the current directory is
.I /usr/bin/X11
(which is still a symbolic link to
.IR /usr/bin ),
the output of both
.br
.RS 4
.nf
.if !'po4a'hide' .BI "realpath " ./xterm
.fi
.RE
and
.RS 4
.nf
.if !'po4a'hide' .BI "realpath  \-s " ./xterm
.fi
.RE
will be
.RS 4
.nf
.if !'po4a'hide' .I /usr/bin/xterm
.ne
.RE

.SS Example 3
Providing that the current directory is
.IR /home/user
(and the directory exists before and during the realpath run),
the  command
.br
.RS 4
.nf
.if !'po4a'hide' .BI "realpath " ../path/to/some/./non-existent/./directory/../or/../file
.fi
.RE
will fail with the following error
.RS 4
.nf
.if !'po4a'hide' .I \&../path/to/some/./non-existent/./directory/../or/../file: No such file or directory
.fi
.RE
but
.RS 4
.nf
.if !'po4a'hide' .BI "realpath \-s " ../path/to/some/./non-existent/./directory/../or/../file
.fi
.RE
will return
.RS 4
.nf
.if !'po4a'hide' .I /home/path/to/some/non-existent/file
.fi
.RE
.SH EXIT STATUS
.B realpath
returns a zero exit code when
.I all
pathnames were successfully converted.
.br
In case of any errors (e.g. missing or unavailable directories in the path),
.B realpath
prints error message to stderr and returns a non-zero exit code.
.RE
.SH "SEE ALSO"
.if !'po4a'hide' .BR basename (1),
.if !'po4a'hide' .BR dirname (1),
.if !'po4a'hide' .BR readlink (1),
.if !'po4a'hide' .BR chase (1),
.if !'po4a'hide' .BR realpath (3)
.SH BUGS
Hopefully none :)
.br
If you find some, please report them via the normal Debian bug reporting system, see the file
.I /usr/share/doc/debian/bug\-reporting.txt
in the package doc\-debian or the
.BR reportbug (1)
man page.
.SH AUTHOR
Originally written by Lars Wirzenius <liw@iki.fi>, as a part of the dwww package.
Robert Luberda <robert@debian.org> currently maintains and extends it.
.PP
realpath is licensed via the GNU General Public License.
While it has been written for Debian, porting it to other
systems is strongly encouraged.