Command to insert lines before first match

Question

I have file with the below info

testing
testing
testing

I want to insert a word(tested) before the first testing word using sed or any linu

Answer 1

This might work for you (GNU sed):

sed -e '/testing/{itested' -e ':a;n;ba}' file

Insert tested before the first match of testing and then use a loop to read/print the remainder of the file.

Or use the GNU specific:

sed '0,/testing/itested' file