Here is a one-liner. It preserves a final "\n" if one or more exists. 
    perl -00 -pe 's/ $/\012/ if s/\n+/ /g and eof' file

[download]
Here are some variations: 
    perl -00 -pe '(eof) ? s/\n\n/\n/ : s/\n+/ /g ' file

    perl -00 -pe 's/\n+/(eof) ? "\n" : " "/eg '    file

[download]
Choose eof or eof() to get the desired effect when dealing with multiple files.

--
John.

In reply to Re: Making my file all one line by jmcnamara
in thread Making my file all one line by Anonymous Monk

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