Removing blanks in a text tab delimited file

Hi Experts
I am very new to perl and need to make a script using perl.
I would like to remove blanks in a text tab delimited file in in a specfic column range ( colum 21 to column 43) sample input and output shown below :

Input:

 
117 102                     650 652 654 656 
117 93 95 111            648 650 656 658 
120 99          647 651 653 655 
117 93                  644 649 
109 87 96 106            645 647 649 655 
652                       645 647 649 
116               87 644 646 650 652 
115 92 98         108 644 646 648 653 
116 88              644 646 649 655 
 

output desired:

117 102 650 652 654 656 
117 93 95 111 648 650 656 658
120 99 647 651 653 655 
117 93 644 649 
109 87 96 106 645 647 649 655
652 645 647 649 
116 87 644 646 650 652 
115 92 98 108 644 646 648 653
116 88 644 646 649 655 

your help is highly appreciated.

Faisal

Cant find any difference. Use code tags to preserve tabs etc.

try this one-liner:

perl -pi -e 's/\s{2,}\w/ /g' filename

With tr:

tr -s ' \t' ' ' < infile