Go alternative for https://codingchallenges.substack.com/p/coding-challenge-43-tr

In this step your goal is to support translating from one character to another, when reading from the standard input. For this your program should start up and wait for a line of input from the user. It will then output the line having made the substitution specified, for example:

% cctr c C
coding challenges
Coding Challenges

Type CTRL-D to send the EOF and terminate cctr.

Try it with the following

go build && echo coding challenges | ./cctr c C

In this step your goal is to support translation of a range of characters. As is common ranges are specified by the start and end separated by a hyphen. For example the upper case letters are A-Z and the lower case letters a-z. When you’ve implemented this it should look something like this:

% head -n3 test.txt
The Project Gutenberg eBook of The Art of War
    
This ebook is for the use of anyone anywhere in the United States and
 
% head -n3 test.txt | cctr A-Z a-z
the project gutenberg ebook of the art of war
    
this ebook is for the use of anyone anywhere in the united states and

Where we can see the first three lines as published by Project Gutenberg, then the same translated to lowercase in the second example.

Try it with the following

go build && head -n3 test.txt | ./cctr A-Z a-z