How to delete strange characters present in some files

What we need first?

An example: you edit a .tex file with the text editor, and save the changes. Then if you open the same file in Emacs is going to appear ``^M'' at the end of every line. This does not affect to the file, but is not nice to the eye. Instead of deleting this ``^M'' by hand or using the method explained in this link (http://www.usc.edu/its/doc/statistics/help/multiuse/garbage.html), you can proceed as follows: First make a copy of the file with the problem (i.e. having ``^M''), let say the file is badfile1.tex and make a copy called badfile2.tex, then type the following at the terminal
then in badfile1.tex is going to appear the fixed file, which you can save as goodfile.tex or whatever. The anyname.tex is empty, and can be deleted.