Could you be more specific? What do you mean by a "fixed length file"? Do you mean fixed length records perhaps? The question then is, how long should the records be? People tend to use comma delimited values over fixed length records because not all their records are fixed length. 
    s/.*/ /

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will replace your lines with fixed length ones - but I doubt that is what you want.
Perl --((8:>*

In reply to Re: convert a comma delimited file to a fixed length by Perl Mouse
in thread convert a comma delimited file to a fixed length by tariqahsan

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