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

A simple function in the bash config file (~/.bashrc often) could work well.

function runx() {
  for ((n=0;n<$1;n++))
    do ${*:2}
  done
}

Call it like this.

$ runx 3 echo 'Hello world'
Hello world
Hello world
Hello world

Answer 2

xargs and seq will help

function __run_times { seq 1 $1| { shift; xargs -i -- "$@"; } }

the view :

abon@abon:~$ __run_times 3  echo hello world
hello world
hello world
hello world

Answer 3

How about the alternate form of for mentioned in (bashref)Looping Constructs?

Answer 4

for run in {1..10}
do
  command
done

Or as a one-liner for those that want to copy and paste easily:

for run in {1..10}; do command; done

Answer 5

If you are OK doing it periodically, you could run the following command to run it every 1 sec indefinitely. You can put other custom checks in place to run it n number of times.

watch -n 1 some_command

If you wish to have visual confirmation of changes, append --differences prior to the ls command.

According to the OSX man page, there's also

The --cumulative option makes highlighting "sticky", presenting a running display of all positions that have ever changed. The -t or --no-title option turns off the header showing the interval, command, and current time at the top of the display, as well as the following blank line.

Linux/Unix man page can be found here

Answer 6

If you're using the zsh shell:

repeat 10 { echo 'Hello' }

Where 10 is the number of times the command will be repeated.