I need to stress-test a program by feeding it input files of progressively larger sizes. I have an input file `inputSmall.txt` which I want to replicate `N` times and `cat` those copies into the same file. `N` is large file. If there anything that would work faster than the following simple loop (e.g. `N=1000`):

```
for i in {1..1000}
do 
    cat inputSmall.txt >> input1000.txt
done

```

My machine has enough disk space to store `inputN.txt` for very large `N`s and has a lot of RAM, in case it's relevant.

Thx