doc: Add hello example

README.md

@@ -59,6 +59,11 @@ Then add it to your packages:
 
 This section explains how to set up a CLI called `hat` using `sub`.
 
+### Hello World
+
+For a working example, check out a [hello
+world])(https://github.com/juanibiapina/sub/tree/master/examples/hello) project.
+
 ### As an alias
 
 The quickest way to get started with `sub` is to define an alias for your CLI

examples/hello/README.md

@@ -0,0 +1,23 @@
+# Hello project
+
+This is an example project on how you can structure your CLI called `hello`
+with a subcommand `world`.
+
+To run it from this repo's root, make sure `sub` is installed and run:
+
+```sh
+./examples/hello/bin/hello
+```
+
+And to actually print "Hello, world!" run:
+
+```sh
+./examples/hello/bin/hello world
+```
+
+If you want to use this project as a template, simply replace the two
+occurrences of `hello` with your CLI name (for example `hat`):
+
+1. The file `bin/hello` should be renamed to `bin/hat`.
+2. The argument `--name hello` in `bin/hello` (now `bin/hat`) should be changed
+   to `--name hat`.

examples/hello/bin/hello

@@ -0,0 +1,5 @@
+#/usr/bin/env bash
+
+set -e
+
+sub --name hello --executable "${BASH_SOURCE[0]}" --relative ".." -- "$@"

examples/hello/libexec/README

@@ -0,0 +1,13 @@
+# Summary: CLI implementation of Hello World
+#
+# A "Hello, World!" program is generally a simple computer program which outputs
+# (or displays) to the screen (often the console) a message similar to "Hello,
+# World!" while ignoring any user input. A small piece of code in most
+# general-purpose programming languages, this program is used to illustrate a
+# language's basic syntax. A "Hello, World!" program is often the first written
+# by a student of a new programming language,[1] but such a program can also be
+# used as a sanity check to ensure that the computer software intended to compile
+# or run source code is correctly installed, and that its operator understands
+# how to use it.
+#
+# https://en.wikipedia.org/wiki/%22Hello,_World!%22_program

examples/hello/libexec/world

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+# Summary: Say hello
+# Usage: {cmd}
+
+set -e
+
+echo "Hello, world!"