On Linux and Mac OS, go into vi, perform the following substitution, and save out the file again, and that should work for you,
$ vi myfile.txt :%s/^V^M/^V^M/g :wq
where ^V^M means type Ctrl+V, then Ctrl+M, and terminate each line with a return.
This should put normal UNIX line terminator characters at the end of the Excel comma separated value lines. You could even create a vi script to automate it if you do it a lot, then call that vi script from a bash script, and hide all this system incongruity away, and call it dos2unix. :-)
To create the vim script in dos2unix.vim, do the following:
Create the script by
$ vi -w dos2unix.vim myfile.txt
Carefully type in the 3 line sequence as mentioned above.
Now apply that scrip to any file with
$ vi -s dos2unix.vim anyfile.txt
And wrapping that all up in a bash script or even an alias, as in, is up to you
alias dos2unix='vi -s ~/.vimscripts/dos2unix.vim '
To be able to do it like it was builtin, because it now will be - just create a folder called, ~/.vimscripts, and put the above created script file there.