nixpkgs-suyu/lib/cli.nix
Gabriel Gonzalez 5edd4dd44c Use a more realistic example that exercises all encodings
... as suggested by @roberth

This also caught a bug in rendering lists, which this change also fixes
2019-12-15 08:21:41 -08:00

52 lines
1.4 KiB
Nix

{ lib }:
{ /* Automatically convert an attribute set to command-line options.
This helps protect against malformed command lines and also to reduce
boilerplate related to command-line construction for simple use cases.
Example:
encodeGNUCommandLine
{ }
{ data = builtins.toJSON { id = 0; };
X = "PUT";
retry = 3;
retry-delay = null;
url = [ "https://example.com/foo" "https://example.com/bar" ];
silent = false;
verbose = true;
};
=> " -X 'PUT' --data '{\"id\":0}' --retry '3' --url 'https://example.com/foo' --url 'https://example.com/bar' --verbose"
*/
encodeGNUCommandLine =
{ renderKey ?
key: if builtins.stringLength key == 1 then "-${key}" else "--${key}"
, renderOption ?
key: value:
if value == null
then ""
else " ${renderKey key} ${lib.escapeShellArg value}"
, renderBool ? key: value: if value then " ${renderKey key}" else ""
, renderList ? key: value: lib.concatMapStrings (renderOption key) value
}:
options:
let
render = key: value:
if builtins.isBool value
then renderBool key value
else if builtins.isList value
then renderList key value
else renderOption key value;
in
lib.concatStrings (lib.mapAttrsToList render options);
}