Adding text to the beginning of a file

Problem

You want to quickly add a piece of text to the beginning of a file.

Solution

The simplest way is to just print the text together with the content of the file to a temporary file, then copy the temporary file to the original file.

    echo 'Begin' | cat - <file> > temp && mv temp <file>

Another way is to use sed program to insert the text to the beginning of the file and use edit in place functionality of sed so that we don't have to create temporary file.

    sed -i '1s/^/Begin\n/' <file>

    # A shorter version
    sed -i '1iBegin' <file>