The Unix program sed is useful for making simple substitutionsthroughout an entire file. But one of its limitations is that italways puts its results onto standard output and therefore itcannot be used to edit a file “in place”. For example, thecommand
sed s/foo/bar/g myFile.txt
will replace every occurrence in myFile.txt of the string “foo”by the string “bar”, with the altered file appearing at thestandard output (i.e., scrolling by on your terminal screen). Butwhat if you really wanted to make this change tomyFile.txt?
…
We could do this in two steps:
mv myFile.txt myFile.txt.baksed s/foo/bar/g myFile.txt.bak > myFile.txt
…
(…) three command-line parameters:
-the string to be replaced
-the string
OR
OR