#!/bin/sh
# from Glass & Ables, Unix for programmers and users, 2003
# slightly revised by cmc, 10/1/2010

# if statement verifies an argument (hoping it is int)
if [ $# -eq 0 ]; then
   echo "Usage: $0 number"
   exit 1
fi

# nested while loops - generate multiplication table
x=1			       		# set outer loop value
while [ $x -le $1 ]			# outer loop
do
  y=1					# set inner loop value
  while [ $y -le $1 ]
  do			       		# generate one table entry
    echo -n `expr $x \* $y` "    "	
    y=`expr $y + 1`			# update inner loop count
  done
  echo					# blank line
  x=`expr $x + 1`			# update outer loop count
done