Insert a line at specific line number with sed or awk

Question

I have a script file which I need to modify with another script to insert a text at the 8th line.

String to insert: Project_Name=sowstest, into a file c

Answer 1

sed -i '8i8 This is Line 8' FILE

inserts at line 8

8 This is Line 8

into file FILE

-i does the modification directly to file FILE, no output to stdout, as mentioned in the comments by glenn jackman.

Answer 2

OS X / macOS / FreeBSD sed

The -i flag works differently on macOS sed than in GNU sed.

Here's the way to use it on macOS / OS X:

sed -i '' '8i\
8 This is Line 8' FILE

See man 1 sed for more info.

Answer 3

the awk answer

awk -v n=8 -v s="Project_Name=sowstest" 'NR == n {print s} {print}' file > file.new