nixpkgs/lib/cli.nix
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{ 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.
`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 =
lib.warnIf (lib.oldestSupportedReleaseIsAtLeast 2511)
"lib.cli.toGNUCommandLineShell is deprecated, please use lib.cli.toCommandLineShell or lib.cli.toCommandLineShellGNU instead."
(options: attrs: lib.escapeShellArgs (lib.cli.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 =
lib.warnIf (lib.oldestSupportedReleaseIsAtLeast 2511)
"lib.cli.toGNUCommandLine is deprecated, please use lib.cli.toCommandLine or lib.cli.toCommandLineShellGNU instead."
(
{
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}${lib.generators.mkValueStringDefault { } v}" ],
optionValueSeparator ? null,
}:
options:
let
render =
k: v:
if builtins.isBool v then
mkBool k v
else if builtins.isList v then
mkList k v
else
mkOption k v;
in
builtins.concatLists (lib.mapAttrsToList render options)
);
/**
Converts the given attributes into a single shell-escaped command-line string.
Similar to `toCommandLineGNU`, but returns a single escaped string instead of an array of arguments.
For further reference see: [`lib.cli.toCommandLineGNU`](#function-library-lib.cli.toCommandLineGNU)
*/
toCommandLineShellGNU =
options: attrs: lib.escapeShellArgs (lib.cli.toCommandLineGNU options attrs);
/**
Converts an attribute set into a list of GNU-style command line options.
`toCommandLineGNU` returns a list of string arguments.
# Inputs
`options`
: Options, see below.
`attrs`
: The attributes to transform into arguments.
## Options
`isLong`
: A function that determines whether an option is long or short.
`explicitBool`
: Whether or not boolean option arguments should be formatted explicitly.
`formatArg`
: A function that turns the option argument into a string.
# Examples
:::{.example}
## `lib.cli.toCommandLineGNU` usage example
```nix
lib.cli.toCommandLineGNU {} {
v = true;
verbose = [true true false null];
i = ".bak";
testsuite = ["unit" "integration"];
e = ["s/a/b/" "s/b/c/"];
n = false;
data = builtins.toJSON {id = 0;};
}
=> [
"--data={\"id\":0}"
"-es/a/b/"
"-es/b/c/"
"-i.bak"
"--testsuite=unit"
"--testsuite=integration"
"-v"
"--verbose"
"--verbose"
]
```
:::
*/
toCommandLineGNU =
{
isLong ? optionName: builtins.stringLength optionName > 1,
explicitBool ? false,
formatArg ? lib.generators.mkValueStringDefault { },
}:
let
optionFormat = optionName: {
option = if isLong optionName then "--${optionName}" else "-${optionName}";
sep = if isLong optionName then "=" else "";
inherit explicitBool formatArg;
};
in
lib.cli.toCommandLine optionFormat;
/**
Converts the given attributes into a single shell-escaped command-line string.
Similar to `toCommandLine`, but returns a single escaped string instead of an array of arguments.
For further reference see: [`lib.cli.toCommandLine`](#function-library-lib.cli.toCommandLine)
*/
toCommandLineShell =
optionFormat: attrs: lib.escapeShellArgs (lib.cli.toCommandLine optionFormat attrs);
/**
Converts an attribute set into a list of command line options.
`toCommandLine` returns a list of string arguments.
# Inputs
`optionFormat`
: The option format that describes how options and their arguments should be formatted.
`attrs`
: The attributes to transform into arguments.
# Examples
:::{.example}
## `lib.cli.toCommandLine` usage example
```nix
let
optionFormat = optionName: {
option = "-${optionName}";
sep = "=";
explicitBool = true;
};
in lib.cli.toCommandLine optionFormat {
v = true;
verbose = [true true false null];
i = ".bak";
testsuite = ["unit" "integration"];
e = ["s/a/b/" "s/b/c/"];
n = false;
data = builtins.toJSON {id = 0;};
}
=> [
"-data={\"id\":0}"
"-e=s/a/b/"
"-e=s/b/c/"
"-i=.bak"
"-n=false"
"-testsuite=unit"
"-testsuite=integration"
"-v=true"
"-verbose=true"
"-verbose=true"
"-verbose=false"
]
```
:::
*/
toCommandLine =
optionFormat: attrs:
let
handlePair =
k: v:
if k == "" then
lib.throw "lib.cli.toCommandLine only accepts non-empty option names."
else if builtins.isList v then
builtins.concatMap (handleOption k) v
else
handleOption k v;
handleOption = k: renderOption (optionFormat k) k;
renderOption =
{
option,
sep,
explicitBool,
formatArg ? lib.generators.mkValueStringDefault { },
}:
k: v:
if v == null || (!explicitBool && v == false) then
[ ]
else if !explicitBool && v == true then
[ option ]
else
let
arg = formatArg v;
in
if sep != null then
[ "${option}${sep}${arg}" ]
else
[
option
arg
];
in
builtins.concatLists (lib.mapAttrsToList handlePair attrs);
}