Brace expansion with a Bash variable - {0..$foo}
bash does brace expansion before variable expansion, so you get weekly.{0..4}.
Because the result is predictable and safe(Don't trust user input), you can use eval in your case:
$ WEEKS_TO_SAVE=4$ eval "mkdir -p weekly.{0..$((WEEKS_TO_SAVE))}"note:
evalis evil- use
evalcarefully
Here, $((..)) is used to force the variable to be evaluated as an integer expression.
Curly braces don't support variables in BASH, you can do this:
for (( c=0; c<=WEEKS_TO_SAVE; c++ )) do mkdir -p weekly.${c} done
Another way of doing it without eval and calling mkdir only once:
WEEKS_TO_SAVE=4mkdir -p $(seq -f "weekly.%.0f" 0 $WEEKS_TO_SAVE)