Sed

Question 1

Sed: how to prepend line of text to a file (at top)?

Answer 1

$ sed -i ‘1s/^/\n/’

Question 2

Sed: how to replace all occurances of search with replace in file?

Answer 2

$ find ./ -type f | xargs sed -i ‘s/search/replace/g’
or
$ sed -i ‘s/search/replace/g’ filename

Question 3

Sed: how to edit files in place?

Answer 3

-i

Question 4

Sed: how to insert text after first line (before second)?

Answer 4

sed -i ‘2 i\JENKINS_HOME=/syna_volume/;’ /etc/init.d/jenkins