toGNUCommandLine

lib.cli.toGNUCommandLine

Docs pulled from | This Revision | 10 minutes ago

Automatically convert an attribute set to a list of command-line options.

toGNUCommandLine returns a list of string arguments.

Inputs

options: How to format the arguments, see below.
attrs: The attributes to transform into arguments.

Options

mkOptionName: How to string-format the option name; By default one character is a short option (-), more than one characters a long option (--).
mkBool: How to format a boolean value to a command list; By default it’s a flag option (only the option name if true, left out completely if false).
mkList: How to format a list value to a command list; By default the option name is repeated for each value and mkOption is applied to the values themselves.
mkOption: How to format any remaining value to a command list; On the toplevel, booleans and lists are handled by mkBool and mkList, though they can still appear as values of a list. By default, everything is printed verbatim and complex types are forbidden (lists, attrsets, functions). null values are omitted.
optionValueSeparator: How to separate an option from its flag; By default, there is no separator, so option -c and value 5 would become ["-c" "5"]. This is useful if the command requires equals, for example, -c=5.

Examples

`lib.cli.toGNUCommandLine` usage example

cli.toGNUCommandLine {} {
  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"
]

Noogle detected

Implementation

The following is the current implementation of this function.

toGNUCommandLine =
    {
      mkOptionName ? k: if builtins.stringLength k == 1 then "-${k}" else "--${k}",

      mkBool ? k: v: lib.optional v (mkOptionName k),

      mkList ? k: v: lib.concatMap (mkOption k) v,

      mkOption ?
        k: v:
        if v == null then
          [ ]
        else if optionValueSeparator == null then
          [
            (mkOptionName k)
            (lib.generators.mkValueStringDefault { } v)
          ]
        else
          [ "${mkOptionName k}${optionValueSeparator}${lib.generators.mkValueStringDefault { } v}" ],

      optionValueSeparator ? null,
    }:
    options:
    let
      render =
        k: v:
        if builtins.isBool v then
          mkBool k v
        else if builtins.isList v then
          mkList k v
        else
          mkOption k v;

    in
    builtins.concatLists (lib.mapAttrsToList render options);