Question

I have a text file and I want to remove the last comma , from the second last line if exist.

a, b, c, d,
m, n, p,
x, y, z,
);

The comma after z needs be removed only.

Answer 1

Give this a try:

sed 'N;$s/,\n/\n/;P;D' inputfile

It removes the comma from the end of the next-to-last line. This assumes that there is nothing after the last line you show.

If you need to key on the contents of that line instead, then this should work:

sed 'N;/)\;/s/,\n/\n/;P;D' inputfile