Is there a better way to run a command N times in bash?

Question

I occasionally run a bash command line like this:

n=0; while [[ $n -lt 10 ]]; do some_command; n=$((n+1)); done

To run some_command

Answer 1

For loops are probably the right way to do it, but here is a fun alternative:

echo -e {1..10}"\n" |xargs -n1 some_command

If you need the iteration number as a parameter for your invocation, use:

echo -e {1..10}"\n" |xargs -I@ echo now I am running iteration @

Edit: It was rightly commented that the solution given above would work smoothly only with simple command runs (no pipes, etc.). you can always use a sh -c to do more complicated stuff, but not worth it.

Another method I use typically is the following function:

rep() { s=$1;shift;e=$1;shift; for x in `seq $s $e`; do c=${@//@/$x};sh -c "$c"; done;}

now you can call it as:

rep 3 10 echo iteration @

The first two numbers give the range. The @ will get translated to the iteration number. Now you can use this with pipes too:

rep 1 10 "ls R@/|wc -l"

with give you the number of files in directories R1 .. R10.