It's hard to say what the best solution would be without knowing exactly what dots you don't want removed, but for the example you give, 

s/\.//;

[download]
does the job. Or 
s/\.(?!txt$)//g

[download]
...or 
s/\.(?![^.]+$)//g

[download]

the lowliest monk

In reply to Re: Removing dots by tlm
in thread Removing dots by Anonymous Monk

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