File: coreutils.info,  Node: Target directory,  Next: Trailing slashes,  Prev: Random sources,  Up: Common options

2.6 Target directory
====================

The ‘cp’, ‘install’, ‘ln’, and ‘mv’ commands normally treat the last
operand specially when it is a directory or a symbolic link to a
directory.  For example, ‘cp source dest’ is equivalent to ‘cp source
dest/source’ if ‘dest’ is a directory.  Sometimes this behavior is not
exactly what is wanted, so these commands support the following options
to allow more fine-grained control:

‘-T’
‘--no-target-directory’
     Do not treat the last operand specially when it is a directory or a
     symbolic link to a directory.  This can help avoid race conditions
     in programs that operate in a shared area.  For example, when the
     command ‘mv /tmp/source /tmp/dest’ succeeds, there is no guarantee
     that ‘/tmp/source’ was renamed to ‘/tmp/dest’: it could have been
     renamed to ‘/tmp/dest/source’ instead, if some other process
     created ‘/tmp/dest’ as a directory.  However, if ‘mv -T /tmp/source
     /tmp/dest’ succeeds, there is no question that ‘/tmp/source’ was
     renamed to ‘/tmp/dest’.

     In the opposite situation, where you want the last operand to be
     treated as a directory and want a diagnostic otherwise, you can use
     the ‘--target-directory’ (‘-t’) option.

‘-t DIRECTORY’
‘--target-directory=DIRECTORY’
     Use DIRECTORY as the directory component of each destination file
     name.

     The interface for most programs is that after processing options
     and a finite (possibly zero) number of fixed-position arguments,
     the remaining argument list is either expected to be empty, or is a
     list of items (usually files) that will all be handled identically.
     The ‘xargs’ program is designed to work well with this convention.

     The commands in the ‘mv’-family are unusual in that they take a
     variable number of arguments with a special case at the _end_
     (namely, the target directory).  This makes it nontrivial to
     perform some operations, e.g., “move all files from here to ../d/”,
     because ‘mv * ../d/’ might exhaust the argument space, and ‘ls |
     xargs ...’ doesn’t have a clean way to specify an extra final
     argument for each invocation of the subject command.  (It can be
     done by going through a shell command, but that requires more human
     labor and brain power than it should.)

     The ‘--target-directory’ (‘-t’) option allows the ‘cp’, ‘install’,
     ‘ln’, and ‘mv’ programs to be used conveniently with ‘xargs’.  For
     example, you can move the files from the current directory to a
     sibling directory, ‘d’ like this:

          ls | xargs mv -t ../d --

     However, this doesn’t move files whose names begin with ‘.’.  If
     you use the GNU ‘find’ program, you can move those files too, with
     this command:

          find . -mindepth 1 -maxdepth 1 \
            | xargs mv -t ../d

     But both of the above approaches fail if there are no files in the
     current directory, or if any file has a name containing a blank or
     some other special characters.  The following example removes those
     limitations and requires both GNU ‘find’ and GNU ‘xargs’:

          find . -mindepth 1 -maxdepth 1 -print0 \
            | xargs --null --no-run-if-empty \
                mv -t ../d

The ‘--target-directory’ (‘-t’) and ‘--no-target-directory’ (‘-T’)
options cannot be combined.