DailyRNG

Build a CLI Tool

Build a CLI Tool

Every lesson in order, step by step. No difficulty tiers. Just follow the arrows.

15 lessons, about 16 min of reading

1

What a command line tool is for →

Step 1 · Basic

2

Arguments as a written shape →

Step 2 · Basic

3

Parsing with a default that is written →

Step 3 · Basic

4

Reading input as a pipe or a name →

Step 4 · Basic

5

Two streams, one meaning each →

Step 5 · Basic

6

Exit codes as a written set →

Step 6 · Basic

7

Help as the tool answering about itself →

Step 7 · Basic

8

Flags as a table with a short and a long name →

Step 8 · Advanced

9

Subcommands as a tree with one leaf →

Step 9 · Advanced

10

A config file as a layer under the words →

Step 10 · Advanced

11

A dry run as the same code with a different write →

Step 11 · Advanced

12

Quiet and loud as one dial with a default →

Step 12 · Advanced

13

A rename tool as a plan that is checked before it runs →

Step 13 · Master

14

A batch over many files as a queue with a point →

Step 14 · Master

15

Shipping a tool with every limit in one file →

Step 15 · Master