2.0.0
Adds "--help" to Deno's std/flags module
Repository
Current version released
3 years ago
Dependencies
std
Versions
flags_usage
Adds “–help” to Deno’s std/flags module, for printing out command line usage/option information.
Example
main.ts:
import { processFlags } from "https://deno.land/x/flags_usage/mod.ts";
const options = {
preamble: "Usage: my-tool <options>", // New: Optional preamble for describing non-flag/positional arguments
description: { output: "Output directory" }, // New: Description of flag
argument: { output: "dir" }, // New: "<dir>" in the output below
string: [ "output" ],
default: { output: "out" },
};
// `processFlags` parses normally, except it will print usage and exit on `--help`
const { output } = processFlags(Deno.args, options);
Output:
$ deno run main.ts --help
Usage: my-tool <options>
Options:
--output <dir> Output directory (default: "out")
-h, -?, --help Display usage information
Note that parseFlags
, logUsage
, etc. (see API) can be used if automatically exiting on --help
is not desirable.
API
Options
All options
arguments follow std/flags’s interface, with the following new, optional properties:
preamble
: An optional string to print out before flag information on--help
description
: An object mapping flags to descriptions that will be displayed on--help
argument
: An object mapping flags to names for their arguments to be displayed on--help
(e.g. mappingout
topath
will display--out <path> ...
instead of the generic--out <str>
for string arguments)
processFlags(Deno.args, options)
Parse options as usual, but add --help
and automatically print usage and exit if --help
/-h
/-?
are specified.
parseFlags(Deno.args, options)
Parse options as usual, with --help
/-h
/-?
added as a Boolean flag (note: with this function, the caller must decide what to do if the help
flag is set to true–use processFlags
to automatically print usage and exit).
formatUsage(options)
Format usage information as a string.
logUsage(options)
Format usage information and print to the console.