title: How to use sed to change file extensions?
body: <p>I have to do a sed line (also using pipes in Linux) to change a file extension, so I can do some kind of <code>mv *.1stextension *.2ndextension</code> like <code>mv *.txt *.c</code>. The thing is that I can't use batch or a for loop, so I have to do it all with pipes and sed command.</p>