std.cli

flags, options, positionals and help text from one command description

CliError

pub CliError :: errors {
    unknown_option,
    missing_value,
    unexpected_value,
    missing_argument,
    too_many_arguments,
    invalid_number,
}

• unknown_option: an option the command does not have
• missing_value: an option that takes a value, at the end
• unexpected_value: a value given to a flag (--verbose=yes)
• missing_argument: too few positional arguments
• too_many_arguments: more than it takes
• invalid_number: int_option of a value that is no integer

Command

pub Command :: struct {
    region: *Arena,
    name: []const u8,
    about: []const u8,
    specs: Vec(Spec),
    places: Vec(PosSpec),
    message: []const u8,
}

Command.flag

pub flag :: fn(self: *Self, long: []const u8, short: u8, about: []const u8)

short 0 = none

Command.option

pub option :: fn(self: *Self, long: []const u8, short: u8, value_name: []const u8, about: []const u8)

takes a value; short 0 = none; value_name shows in help (FILE, N)

Command.positional

pub positional :: fn(self: *Self, name: []const u8, about: []const u8)

required; positionals match in declaration order

Command.optional

pub optional :: fn(self: *Self, name: []const u8, about: []const u8)

may be omitted; goes after the required ones

Command.rest

pub rest :: fn(self: *Self, name: []const u8, about: []const u8)

any number after the others (files…)

Command.parse

pub parse :: fn(self: *Self, args: []const []const u8) -> Parsed ! CliError

skips args[0]; –x V, –x=V, -o V, -oV, -vq; -- ends options; -h skips checks

Command.help

pub help :: fn(self: *Self, a: *Arena) -> []const u8

usage and options text, in a

Parsed

pub Parsed :: struct {
    given: Vec(Given),
    positionals: Vec([]const u8),
    help: bool,
}

Parsed.flag

pub flag :: fn(self: *Self, long: []const u8) -> bool

flag or option given at all

Parsed.count

pub count :: fn(self: *Self, long: []const u8) -> usize

times given (-vvv is 3)

Parsed.option

pub option :: fn(self: *Self, long: []const u8) -> ?[]const u8

last value if repeated; null if not given

Parsed.all

pub all :: fn(self: *Self, a: *Arena, long: []const u8) -> []const []const u8

all values in order (-I a -I b), in a

Parsed.int_option

pub int_option :: fn(self: *Self, long: []const u8) -> ?i64 ! CliError

null if not given; .invalid_number if not an integer

Parsed.positional

pub positional :: fn(self: *Self, i: usize) -> ?[]const u8

Parsed.positionals_all

pub positionals_all :: fn(self: *Self) -> []const []const u8

command

pub command :: fn(a: *Arena, name: []const u8, about: []const u8) -> Command

name as help shows it; everything lives in a