Append to same line in Bash

Question

The file letters.csv contains:

b,a,c,

The file numbers.csv contains:

32
34
25
13

I would like to append numbe

Answer 1

You can use tr:

cat letters.csv numbers.csv | tr '\n' ',' | sed 's/,$/\n/'

(I hope this is not a useless use of cat. :-))

The sed at the end is needed to replace the last , with a newline character.