initiation à SED
Want to use sed(1) to edit a file in place?
Well, to replace every 'e' with an 'o', in a file named 'foo', you can do:
# sed -i.bak s/e/o/g foo
And you'll get a backup of the original in a file named 'foo.bak'.
but if you want no backup:
# sed -i '' s/e/o/g foo