BEGIN and END blocks in awk - awk

Question

I am using the awk command in terminal on my Mac.
I want to print the contents of an already existing file and give a title to each column which i'll separate using a tab then I want to send the output to another file. What line of code would I use to give titles to the columns? Im hoping to use simple awk commands and preferably if I can complete the task in as little lines as possible.
So far I have tried to use the BEGIN command. (The titles I want to give are first name, second name and score)
BEGIN { print "First Name\tSecond Name\tScore}**
then I want to print the entire contents of the file.
{print} filename.txt
Finally I want to save the output to another file
End{print} filename.txt > output.txt
to do this all all together
awk 'BEGIN {print "First Name\tSecond Name\tScore";}
{print}
End{print}' filename.txt > output.txt
However, this only saved the titles to the output file and not the contents of the original file under the columns.

Answer 1

awk processes files line by line. Before it starts processing the file you can have it do something. We use the BEGIN keyword to note that the following block of code is to be executed before processing. Same with END running after the processing of each line of the file is complete.
While your code has some superfluous bits in it, like the unnecessary END block, it still should do exactly what you are wanting to do, assuming you have data in your filename.txt.
A more succinct awk code would be:
awk 'BEGIN {print "First Name\tSecond Name\tScore";}1' filename.txt > output.txt
In action (using commas instead of tabs because it's easier and I'm lazy):
$ echo "1,2,3" > filename.txt
$ awk 'BEGIN {print "c1,c2,c3"}1' filename.txt > output.txt
$ cat output.txt
c1,c2,c3
1,2,3