Bash run a command every n seconds

#!/bin/bash
# Save this file at e.g. /usr/bin/shevery

INTERVAL=${INTERVAL:-1}

if [ -z "$1" ]; then
  >&2 echo "Missing command to run"
  exit 1
fi

while true; do
  # Run command
  $@
  sleep $INTERVAL
done

Usage

$ shevery date
Fri Feb 24 10:25:45 CET 2017
Fri Feb 24 10:25:46 CET 2017
Fri Feb 24 10:25:47 CET 2017
Fri Feb 24 10:25:48 CET 2017
Fri Feb 24 10:25:49 CET 2017