scripting - Using sed, Insert a line above or below the pattern?

Question

This question already has answers here:

Answer 1

To append after the pattern: (-i is for in place replace). line1 and line2 are the lines you want to append(or prepend)

sed -i '/pattern/a 
line1 
line2' inputfile

Output:

#cat inputfile
 pattern
 line1 line2 

To prepend the lines before:

sed -i '/pattern/i 
line1 
line2' inputfile

Output:

#cat inputfile
 line1 line2 
 pattern