Shell Programming and Scripting

My input file:
Class
Number Position Range
1 Initial 50
1 Initial 50
2 Terminal 150
2 Terminal 20
2 Single 10
3 Single 20
4 Double 50
5 Initial 50
5 Initial 60

Class
Number Position Range
1 Initial 150
2 Terminal 250
2 Terminal 200
3 Single 20
4 Double 50
4 Single 100
5 Initial 100
.
.
.

My output file:
Class
Number Position Range

1 Initial 50
1 Initial 50

2 Terminal 150
2 Terminal 20
2 Single 10

3 Single 20

4 Double 50

5 Initial 50
5 Initial 60

Class
Number Position Range

1 Initial 150

2 Terminal 250
2 Terminal 200

3 Single 20

4 Double 50
4 Single 100

5 Initial 100

.
.
.

I got a long list of file. How can I added new line by using awk,sed, or perl based on the numerical number of column 1?
Each section of the content begin with "Class".
Thanks a lot for suggestion.

Code:

number=1
outputFile="/tmp/output"

for line in `cat inputFile`
do
    if (`awk -F" " '{print $1}'` -eq $number )
    then
          echo $line >> $outputFile
    else
          echo "\n$line" >> $outputFile
          $number++;
    fi
done

Hi tene,
I just try the script that you suggestion, but it seems like can't work?
Do I got did anything wrong?
Thanks for your reply.

try this :

Code:

#!/bin/bash
NN=""
outputFile="/tmp/output"
while read N LINE
do
    [ "$NN" != "$N" ] && echo
    echo "$N $LINE"
    NN=$N
done < $inputfile > $outputfile

Or with awk:

Code:

awk '
   (NR > 2) && (X != $1) { print "" } { X = $1 } 1
' input_file > output_file

Number Position Range
1 Initial 50
1 Initial 50

2 Terminal 150
2 Terminal 20
2 Single 10

3 Single 20

4 Double 50

5 Initial 50
5 Initial 60

thanks a lot, frans.
Your code work perfectly
Do you mind roughly to explain the back story behind your code?
Thanks again.

---------- Post updated at 03:04 AM ---------- Previous update was at 03:01 AM ----------

thanks scottn.
Your code is worked as well ^^
thanks for sharing

I just gave you the logic.
Did u add #!/usr/bin/ksh at the top.

What error are you getting?