nixpkgs/lib/cli.nix

149 lines
3.8 KiB
Nix
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{ lib }:
rec {
/**
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.
`toGNUCommandLineShell` returns an escaped shell string.
# Inputs
`options`
: How to format the arguments, see `toGNUCommandLine`
`attrs`
: The attributes to transform into arguments.
# Examples
:::{.example}
## `lib.cli.toGNUCommandLineShell` usage example
```nix
cli.toGNUCommandLineShell {} {
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'";
```
:::
*/
toGNUCommandLineShell =
options: attrs: lib.escapeShellArgs (toGNUCommandLine options attrs);
/**
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 its 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
:::{.example}
## `lib.cli.toGNUCommandLine` usage example
```nix
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"
]
```
:::
*/
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);
}