Ubuntu Manpages

realpath

return the canonicalised absolute pathname

realpath [-s|--strip] [-z|--zero] filename ...
realpath --h|--help
realpath --v|--version

realpath converts each filename argument to an absolute pathname, which has no components that are symbolic links or the special . or .. directory entries. (See realpath(3) for more information.)
Each path component in the filename must exist, otherwise realpath will fail and non-zero exit status will be returned.
Please note that mostly the same functionality is provided by the `-e' option of the readlink(1) command.

When the -s option is used realpath only removes the . and .. directories, but not symbolic links from filename. If the given filename argument is relative (i.e. does not start with `/'), realpath -s prepends to it the current directory name as obtained from the getcwd(2) system call before further processing.

Each converted pathname is output to the standard output, on its own line.

Only strip . and .., components, but do not resolve symbolic links.
Separate output filenames with the null character instead of newline, so it can be used with the `-0' option of xargs(1).
Print short usage information.
Show realpath's version number.

For the examples below let's suppose that /usr/bin/X11 is a symbolic link, pointing to directory /usr/bin.

Regardless of what the current directory is 

realpath /../usr/bin/X11/./xterm
prints 
/usr/bin/xterm
but 
realpath -s /../usr/bin/X11/./xterm
outputs 
/usr/bin/X11/xterm

When the current directory is /usr/bin/X11 (which is still a symbolic link to /usr/bin), the output of both 

realpath ./xterm
and 
realpath  -s ./xterm
will be 
/usr/bin/xterm








Providing that the current directory is /home/user (and the
    directory exists before and during the realpath run), the command
  






realpath ../path/to/some/./non-existent/./directory/../or/../file



will fail with the following error



../path/to/some/./non-existent/./directory/../or/../file: No such file or directory



but



realpath -s ../path/to/some/./non-existent/./directory/../or/../file



will return



/home/path/to/some/non-existent/file










realpath returns a zero exit code when all pathnames
    were successfully converted.
  

  In case of any errors (e.g. missing or unavailable directories in the path),
    realpath prints error message to stderr and returns a non-zero exit
    code.






basename(1), dirname(1), readlink(1),
    chase(1), realpath(3)






Hopefully none :)
  

  If you find some, please report them via the normal Debian bug reporting
    system, see the file /usr/share/doc/debian/bug-reporting.txt in the
    package doc-debian or the reportbug(1) man page.






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.


realpath is licensed via the GNU General Public License. While it
    has been written for Debian, porting it to other systems is strongly
    encouraged.