I have a sh script that, if it is invoked by the command `./textgenerate text0`, a file `text0.txt` would be generated. 

Now that I need `text0.txt`, `text1.txt`, ..., `text1000.txt`, how could I write the script to do that. i.e., how to replace the `0` part to changing variables, say 1~1000?

I know a certain "trick" to implement this, for example generate the script 1000 times using Microsoft Excel and paste it into the shell. But is there an elegent and efficient way to do this?