Problem Statement

Create a file called   "output.txt",   and place in it the contents of the file   "input.txt",   via an intermediate variable. In other words, your program will demonstrate:

Oneliners that skip the intermediate variable are of secondary interest — operating systems have copy commands for that.

Let's start with the solution:

#!/bin/sh
while IFS= read -r a; do
    printf '%s\n' "$a"
done output.txt

#!/bin/sh
cat input.txt >output.txt

#!/bin/sh
cp input.txt output.txt