#!/bin/bash
function get_i_j {
 local file=$1 i=$2 j=$3 a_i_j i1 j1 w
 i1=1
 while read line; do
   w=$(echo $line | wc -w)
   for j1 in $(seq $w); do
     a_i_j=$(echo $line|cut -d" " -f$j)
     if [ $i -eq $i1 -a $j -eq $j1 ]; then
        echo $a_i_j
        return
     fi
   done
   ((i1++))
   done<$file
 echo 0
}
function matrix_difference {
 local file1=$1 file2=$2 i=1 j n a_i_j b_i_j w
 >|tmp
 while read line; do
   w=$(echo $line | wc -w)
   s=""
   for j in $(seq $w); do
     a_i_j=$(echo $line|cut -d" " -f$j)
     b_i_j=$(get_i_j $file2 $i $j)
         s=$s" "$[a_i_j-b_i_j]
   done
   echo $s >> tmp
   ((i++))
 done<$file1
}
last_name=$(echo $* |tr " " -)
last_line="The matrix difference ${last_name} is:"
for i in $@;do
   echo "The matrix $i is:"
   cat $i
done
matrix_difference $1 $2 
shift;shift; 
for i in $@;do
   cp tmp tmp1
   matrix_difference tmp1 $i
done
echo $last_line
cat tmp