Using a count variable in a file name

Question

I have a quick question. I just wanted to know if it was valid format (using bash shell scripting) to have a counter for a loop in a file name. I am thinking something along the lines of:

for((i=1; i <=12; i++))
do
  STUFF
  make a file(i).txt

Answer 1

Here's a quick demonstration. The touch command updates the last-modified time on the file, or creates it if it doesn't exist.

for ((i=1; i<=12; i++)); do
   filename="file$i.txt"
   touch "$filename"
done

You may want to add leading zeroes to the cases where $i is only one digit:

for ((i=1; i<=12; i++)); do
   filename="$(printf "file%02d.txt" "$i")"
   touch "$filename"
done

This will result in file01.txt, file02.txt, and so on, instead of file1.txt, file2.txt.