How to add a blank line before the first line in a text file with awk

Question

I have some text files. I would like to add a blank line before the first line in each text file. How can I do this with awk?

Answer 1

I would prefer GNU sed for this task:

To add a space to the beginning of the file:

sed '1s/.*/ &/' file.txt

To perform this on multiple text files with the .txt extension, and make the changes directly to the files (i.e. overwrite them), try:

sed -s -i '1s/.*/ &/' *.txt

To add a blank line at the beginning of the file:

sed '1i\\' file.txt

To perform this on multiple text files with the .txt extension, and make the changes directly to the files (i.e. overwrite them), try:

sed -s -i '1i\\' *.txt

Answer 2

This will give you a blank space at the start of your data file:

 awk 'BEGIN{printf(" ")}1' data.txt

Alternatively, this will give you a blank line at the start of your data file.

 awk 'BEGIN{print""}1' data.txt