Insertion Sort Shell Script

#!/bin/bash#!/bin/bash
# SCRIPT: insertionsort.sh
#
# LOGIC: Here, sorting takes place by inserting a particular element
# at the appropriate position, that’s why the name insertion sorting.
# In the First iteration, second element ARRAY[1] is compared with
# the first element ARRAY[0]. In the second iteration third element
# is compared with first and second element. In general, in every
# iteration an element is compared with all the elements before it.
# While comparing if it is found that the element can be inserted at
# a suitable position, then space is created for it by shifting the
# other elements one position up and inserts the desired element at
# the suitable position. This procedure is repeated for all the
# elements in the list.
#
#####################################################################
#                      Define Functions Here                        #
#####################################################################

printnumbers()
{
echo ${ARRAY[*]}
}

sortnumbers()
{
for((i=1;i<count;i++))
do
   Temp=${ARRAY[i]}
   j=$((i-1))
   while [ $Temp -lt ${ARRAY[j]} ]
   do
      ARRAY[j+1]=${ARRAY[j]}
      let j--
      if [ $j == -1 ]
      then
         break
      fi
   done
   ARRAY[j+1]=$Temp
done
}

#####################################################################
#                       Variable Initialization                     #
#####################################################################

echo "Enter numbers to be sorted"

read -a ARRAY

count=${#ARRAY[@]}

#####################################################################
#                       Main Script Starts Here                     #
#####################################################################

echo "---------------------------------------------------------------"

echo "Numbers Before Sort:"

printnumbers

sortnumbers

echo "Numbers After Sort: "

printnumbers

echo "---------------------------------------------------------------"



OUTPUT:

[root@www blog]# sh insertionsort.sh
Enter Numbers to be Sorted :
12 76 34 -34 67 9 -56 5 99 -3 17
---------------------------------------------------------------
Numbers Before Sort:
12 76 34 -34 67 9 -56 5 99 -3 17
Numbers After Sort:
-56 -34 -3 5 9 12 17 34 67 76 99
---------------------------------------------------------------

NOTE: If we complement the while condition in this program, it will
give out the sorted array in descending order.