diff --git a/lib/cli.nix b/lib/cli.nix index 067ee21696a..c96d4dbb043 100644 --- a/lib/cli.nix +++ b/lib/cli.nix @@ -42,20 +42,34 @@ rec { toGNUCommandLineShell = options: attrs: lib.escapeShellArgs (toGNUCommandLine options attrs); - toGNUCommandLine = - { mkKey ? - k: if builtins.stringLength k == 1 - then "-${k}" - else "--${k}" + toGNUCommandLine = { + # how to string-format the option name; + # by default one character is a short option (`-`), + # more than one characters a long option (`--`). + mkOptionName ? + k: if builtins.stringLength k == 1 + then "-${k}" + else "--${k}", - , mkOption ? - k: v: if v == null - then [] - else [ (mkKey k) (builtins.toString v) ] + # 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). + mkBool ? k: v: lib.optional v (mkOptionName k), - , mkBool ? k: v: lib.optional v (mkKey k) + # 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. + mkList ? k: v: lib.concatMap (mkOption k) v, - , mkList ? k: v: lib.concatMap (mkOption k) v + # 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. + mkOption ? + k: v: if v == null + then [] + else [ (mkOptionName k) (lib.generators.mkValueStringDefault {} v) ] }: options: let