Cron: running cron every 1 second?

Question

How can I run cron every 1 second? there's only minutes option by default

Answer 1

Let cron start the job one time, the first time. Put the program in an infinite loop, sleep() for 1 second at the end of each loop. like this, in C:

  int main( int argc, char ** argv ) {
      while (1) {
        // do the work
        sleep(1000);
      }
  }

Could that work?

Answer 2

Cron executes stuff every minute. Use a script:

while :
do
    sleep 1
    some_command || break
done

or in one line:

while : ; do sleep 1 ; some_command || break ; done

This will wait 1 second in between each execution, so if your command takes .75 seconds to run, then this script will kick it off every 1.75 seconds.