Add Move A List Of Files To Another Directory as a Unix TIL

unix/move-a-list-of-files-to-another-directory.md

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+# Move A List Of Files To Another Directory
+
+Let's say I have some command I run (it doesn't matter what it is) that produces
+a list of files I want to deal with. For instance, how about all the markdown
+files in some directory -- `fd -e md . docs`.
+
+Whatever that list of files is, I want to move them to another directory. To do
+that I can pipe the list to `mv` via `xargs`. The built-in `mv` command on MacOS
+can take a list of one or more source files followed by a single target
+directory. So I need `xargs` to inject the filename for the current line being
+processed into the middle of each `mv` that gets executed.
+
+```bash
+❯ fd -e md . docs | xargs -IFILE mv FILE ../target/dir
+# essentially:
+# mv docs/file1.md ../target/dir
+# mv docs/file2.md ../target/dir
+# mv docs/file3.md ../target/dir
+```
+
+The `-I` flag lets me define a token (e.g. `FILE`) that represents a line from
+the source input. I can then inject that token anywhere in the command that
+`xargs` is evaluating. This `mv` command gets run once for each line (that is,
+each file name) from the source input.
+
+A slightly easier way to approach this if I have [GNU
+CoreUtils](https://formulae.brew.sh/formula/coreutils) installed is to use their
+version of `mv` ([which will be `gmv` for
+me](/mac/access-coreutils-that-conflict-with-unix-utilities.md)) which has the
+`-t` flag. With that form, I can specify the target directory first with `-t`
+and then `xargs` can naturally inject all the file names from the source input
+at the end of the line.
+
+```bash
+❯ fd -e md . docs | xargs gmv -t ../target/dir
+# essentially:
+# gmv -t ../target/dir docs/file1.md docs/file2.md docs/file3.md
+```
+
+See `man xargs` as well as `man mv` and `man gmv` for more details.