A simple bash function for retrying commands until they succeed.

L is for loop

#!/bin/bash

# 'Loop' command 
# I use this mostly for when machines are booting up and I don't want to
# keep manually trying to ssh over to them
function L {
  local interval
  if [[ $# -eq 0 || $1 = --help || $1 = -h || $1 = -\? ]]; then
    echo "Usage: L [-N] COMMAND"
    echo "Runs COMMAND [waiting N sec between failed attempts] until it succeeds"
    echo "If wait interval N is not specified, it defaults to 2 sec"
  else
    [[ ${1#-} -gt 0 ]] && { interval=${1#-}; shift; } || interval=2
    until $@; do
      sleep $interval
    done
  fi
}