On Mac OSX how do I add a line to a file using sed when the file is empty?

Question

This works fine

$ sed -i '' '1i\
my text' $HOME/.bashrc

when there is a line one, but has no effect when there is no line one.

Answer 1

One way, will works in both cases :

{ echo my text; cat file; } | tee file

This work for small files, for big files, use a temporary file :

{ echo my text; cat file; } > temp$$ && mv temp$$ file