Convert Line Endings In Textmate

Goto Text > Filter Through Command

Menu in Textmate "Text -> Filter Through Command"

Set Input to “Document”
Set Output to “Replace Document”
Use this sed one-liner as your command to convert from Unix to DOS:

sed "s/$/`echo -e \\\r`/"

Screenshot of "Filter through command" dialog in Textmate

Convert line endings from Unix to Dos using Sed in Textmate for current document