Note that if vi in your system is actually vim, you won't see the ^M characters displayed. Vim sees the \r\n line endings and opens up the file in dos format, wherein it silently preserves the dos line endings. It will show this when it starts up as part of displaying the file name, line and character counts:

     "foo" [dos] 3L, 9C
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To have vim strip the ^M characters for you, change the file format to "unix" as follows:

      :set ff=unix
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