#!/bin/sh
# string multiply

if [ $# -le 1 ]; then
  echo "Usage: ${0##*/} <str> <n>" >&2
  exit 1
fi

s="$1"
shift 1
while [ $# -gt 1 ]; do
   s="$s $1"
   shift 1
done

case $1 in
    ''|*[!0-9]*) echo "$2 is not a valid number" >&2; exit 2 ;;
esac

i=0
while [ $i -lt $1 ]; do
  printf "%s" "$s"
  : $((i += 1))
done