Question

I am trying to insert some copy-right information into the beginning of some source files. I know that using sed in the following way:

sed "1iSome copyrighted information." sample.txt

would insert the text “Some copyrighted information” to the beginning of sample.txt.
I need to insert text from a file to the beginning of sample.txt. Is there any way in sed that I could use a cat command for the above purpose, say something like the following?:

sed "1i{cat header.txt}" sample.txt

I have googled for the above and have not found exactly what I have been looking for. Any help on this is most welcome.

Thanks.

Answer 1

Use ed text editor:

echo -e '0r header.txt\nw' | ed sample.txt

or use vi/ex command:

vi - +'0r header.txt|wq' sample.txt

But I don’t see any way to run a command in sed.