awk-Printing column value without new line and adding comma

awk 'BEGIN{ORS=","}1' input.txt

yields this:

EN1,EN2,EN3,EN4,EN5,

so is printing with a comma (so I'm not sure I understand your comment in your post about this not happening) though I suspect the trailing comma is a problem.

Tested with GNU Awk 3.1.7

You can use tr in such situation.

tr '\n' ',' <input.txt

This replaces the final newline by a comma as well. To avoid this, on Linux, if you know that the input file does end with a newline:

<input.txt head -c -1 | tr '\n' ,

Add ; echo if you want the output to be terminated by a newline.

Alternatively, you can get the shell to remove a trailing comma if there is one.

columns=$(<input.txt tr '\n' ',')
echo "${columns%,}"

I know, old topic, but I could not resist - here's yet another short and simple way to do this:

$ paste -sd, input.txt
EN1,EN2,EN3,EN4,EN5
$

Works on Linux and Solaris, maybe even on other platforms.