Why does the input to xargs is 1 string but without is strings in separate line?

Question

I am trying to pipe file to rm via xargs. I understand that what I am tryng to do could be done by git clean but I am practicing the cli.
I tried this:

for files in $(git status --porcelain| sed 's/^??//g'); do echo $files; done | xargs rm -rf

but it did not work. I figured it was because when running this:

for files in $(git status --porcelain| sed 's/^??//g'); do echo $files; done | xargs

The files seem to be in 1 string separated by a space.
But when I run for files in $(git status --porcelain| sed 's/^??//g'); do echo -n $files; done the files are displayed in the console in a separate line.

So (if I am right on this) what is the difference between:
for files in $(git status --porcelain| sed 's/^??//g'); do echo -n $files; done | xargs
and

for files in $(git status --porcelain| sed 's/^??//g'); do echo -n $files; done

and the files in the second case are displayed each in each own line and in the first case it is one string? And how would I fix this so that it works with rm -rf?

Answer 1

You are making your life more complicated than necessary ;-)

If the subshell command (the expression inside your $()) already provides a list of filenames, and the "target command" (rm -rf in your case) already accepts a list of filenames, why not just use

git status --porcelain| sed 's/^??//g' | xargs rm -rf

Or, if you wish to practice a "for loop" in bash, you don't need xargs:

for f in $(git status --porcelain| sed 's/^??//g') ; do
    rm -rf $f
done

BTW... doubly check your 'rm -rf' commands (adding an 'echo' before 'rm -rf') before executing them, silly errors happen and you'll regret it!!