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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:
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.
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
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.