A simple package for building command line apps in Zig.

Inspired by urfave/cli Go package.

• command line arguments are parsed into zig values
• long and short options: --option1, -o
• optional = sign: --address=127.0.0.1 equals --address 127.0.0.1
• concatenated short options: -a -b -c equals -abc
• subcommands: command1 -option1 subcommand2 -option2
• multiple option values: --opt val1 --opt val2 --opt val3
• enums as option values: --opt EnumValue1
• options value can be read from environment variables with a configured prefix
• positional arguments can be mixed with options: --opt1 val1 arg1 -v
• stops option parsing after --: command -- --abc will consider --abc as a positional argument to command.
• errors on missing required options: ERROR: option 'ip' is required
• prints help with --help
• colored help messages when TTY is attached

const std = @import("std");
const cli = @import("zig-cli");

var gpa = std.heap.GeneralPurposeAllocator(.{}){};
const allocator = gpa.allocator();

var config = struct {
    host: []const u8 = "localhost",
    port: u16 = undefined,
}{};

var host = cli.Option{
    .long_name = "host",
    .help = "host to listen on",
    .value_ref = cli.mkRef(&config.host),
};
var port = cli.Option{
    .long_name = "port",
    .help = "port to bind to",
    .required = true,
    .value_ref = cli.mkRef(&config.port),
};
var app = &cli.App{
    .name = "short",
    .options = &.{ &host, &port },
    .action = run_server,
};

pub fn main() !void {
    return cli.run(app, allocator);
}

fn run_server(_: []const []const u8) !void {
    std.log.debug("server is listening on {s}:{}", .{ config.host, config.port });
}

See simple.zig

$ ./zig-out/bin/simple sub1 --help
USAGE:
  abc sub1 [OPTIONS]

another awesome command

this is my awesome multiline description.
This is already line 2.
And this is line 3.

COMMANDS:
  sub2   sub2 help

OPTIONS:
  -i, --ip <IP>         this is the IP address
      --int <VALUE>     this is an int
      --bool            this is a bool
      --float <VALUE>   this is a float
  -h, --help            Prints help information

MIT