Why ls -1 | xargs -I{} echo -n {}{}{} does not print in right order?

Question

Ubuntu$ ls -1

file1 file2

Ubuntu$ ls -1 | xargs -I{} echo -n {}{}{}

file1file1file1file2file2file2

Why don't I get the result in this order?: file1file2file1file2file1fil2

Answer 1

Because xargs executes the command (echo) for each word in its input. And of course {} is the same each time. Even if you repeat it many times.

You can do what you want using for:

ls=$(ls -1)
for i in {1..3}
do
  echo $ls
done

Example of usage:

$ mkdir d ; cd d
<d>$ touch file1 file2 file3
<d>$ ls=$(ls -1)
<d>$ for i in {1..3}
> do
>   echo $ls
> done
file1 file2 file3
file1 file2 file3
file1 file2 file3