Last thread was closed due to lack of updates, but Prism has been updated to support Mojo 0.26.2!
Inspired by: Cobra and urfave/cli!
There’s lot’s of examples in the README and in the examples directory, but here’s a full-ish API example:
from std.sys import exit, stderr
from prism import Command, Flag, FlagSet, Version, no_args, read_args
fn base(args: List[String], flags: FlagSet) -> None:
print("Pass a subcommand!")
fn connect(args: List[String], flags: FlagSet) raises -> None:
if host := flags.get_string("host"):
print("Connecting to", host.value())
else:
raise Error("Error: Exit Code 2")
fn my_exit(e: Error) -> None:
print(e, file=stderr)
if String(e) == "Error: Exit Code 2":
print("Exiting with code 2")
exit(2)
else:
exit(1)
fn allow_hosts(args: List[String], flags: FlagSet) raises -> None:
var hosts = flags.get_string_list("hosts")
if not hosts:
print("Received no names to print.")
return
print("Allowing: ", hosts.value())
fn version(version: String) -> String:
return "MyCLI version: " + version
fn validate_hosts(value: String) raises -> None:
var approved_hosts: List[String] = ["localhost", "0.0.0.0", "192.168.1.1"]
var hosts = value.split(" ")
for host in hosts:
if String(host) not in approved_hosts:
raise Error(
"ValueError: Host provided is not permitted.\nReceived: ",
host,
" Approved: ",
approved_hosts,
)
fn main() -> None:
var cli = Command(
name="connector",
usage="Base Command.",
run=base,
exit=my_exit,
version=Version("0.1.0", action=version),
suggest=True,
flags=[
Flag.bool(name="required", shorthand="r0", usage="Always required.", required=True, persistent=True),
Flag.string(
name="host",
shorthand="h",
usage="Host",
persistent=True,
environment_variable="CONNECTOR_HOST",
file_path="~/.myapp/config",
default="localhost",
),
Flag.string(
name="port",
shorthand="p",
usage="Port",
persistent=True,
),
Flag.bool(
name="automation",
shorthand="a",
usage="In automation?",
persistent=True,
),
Flag.bool(
name="verbose",
shorthand="vv",
usage="Verbose output.",
persistent=True,
),
],
flags_required_together=["host", "port"],
children=[
Command(
name="connect",
usage="Connect to a database.",
run=connect,
aliases=["db-connect"],
flags=[
Flag.bool(
name="also",
shorthand="a",
usage="Also always required.",
required=True,
),
Flag.string(
name="uri",
shorthand="u",
usage="URI",
),
],
arg_validator=no_args,
suggest=True,
),
Command(
name="allow",
usage="Add hosts to the allow list!",
run=allow_hosts,
flags=[
Flag.string_list(
name="hosts",
shorthand="hl",
usage="Hosts to add to the allowlist.",
default=["localhost", "0.0.0.0"],
action=validate_hosts,
)
],
),
],
)
cli.execute(read_args())
Some alternatives:
