command_alias

name

def name(
    *,
    name: str,
    default_target_platform: None | str = ...,
    target_compatible_with: list[str] = ...,
    compatible_with: list[str] = ...,
    exec_compatible_with: list[str] = ...,
    visibility: list[str] = ...,
    within_view: list[str] = ...,
    metadata: OpaqueMetadata = ...,
    tests: list[str] = ...,
    modifiers: OpaqueMetadata = ...,
    _apple_platforms: dict[str, str] = ...,
    _exec_os_type: str = ...,
    _target_os_type: str = ...,
    args: list[str] = ...,
    contacts: list[str] = ...,
    default_host_platform: None | str = ...,
    env: dict[str, str] = ...,
    exe: None | str = ...,
    labels: list[str] = ...,
    licenses: list[str] = ...,
    platform_exe: dict[str, str] = ...,
    resources: list[str] = ...,
    run_using_single_arg: bool = ...,
) -> None

The command_alias rule enables you to wrap build rules that create binaries and to pre-apply command-line arguments and environment variables.

Parameters

name: name of the target
default_target_platform: specifies the default target platform, used when no platforms are specified on the command line
target_compatible_with: a list of constraints that are required to be satisfied for this target to be compatible with a configuration
compatible_with: a list of constraints that are required to be satisfied for this target to be compatible with a configuration
exec_compatible_with: a list of constraints that are required to be satisfied for this target to be compatible with an execution platform
visibility: a list of visibility patterns restricting what targets can depend on this one
within_view: a list of visibility patterns restricting what this target can depend on
metadata: a key-value map of metadata associated with this target
tests: a list of targets that provide tests for this one
modifiers: an array of modifiers associated with this target
args: A string of arguments that is passed to the executable specified by exe at startup. These arguments support a subset of Buck's string parameter macros . Only the $(location ...) and $(exe ...) macros are supported currently.
env: A map of environment variables that will be passed to the executable represented by exe on startup. Environment variables support the same macros as arguments.
exe: A build target for a rule that outputs an executable, such as an sh_binary(), or an executable source file.
platform_exe: A mapping from platforms to build target. enables you to override exe per host platform.

If present, exe will be used as a fallback on host platforms that are not specified in platform_exe.

It is possible to omit exe when providing platform_exe. In that case, the build will fail if the command is invoked on a platform not specified in the mapping.

Valid platforms are all values of the Platform enum :
- FREEBSD
- LINUX
- MACOS
- WINDOWS
run_using_single_arg: Ensure that the command alias can be run as a single argument (instead of $(exe) or RunInfo potentially expanding to multiple arguments).

Details

Example uses include running a command written in a scripting language with a specific interpreter, and transparently wrapping sub-commands of a binary.

You can reference a command_alias target in the cmd parameter of a genrule() by using the exe macro:

$(exe //path/to:target)

Examples:

# Combining an interpreter and a script

cxx_binary(
    name = "node-js",
    srcs = [
        # ...
    ],
    headers = [
        # ...
    ],
)

export_file(
    name = "scripts"
)

command_alias(
    name = "server",
    exe = ":node-js",
    args = [
        "$(location :scripts)/start-server.js",
    ],
)

# Exposing sub commands

export_file(
    name = "yarn",
    src = "yarn.sh",
)

command_alias(
    name = "add",
    exe = ":yarn",
    args = ["add"],
)

command_alias(
    name = "install",
    exe = ":yarn",
    args = ["install"],
)

command_alias(
    name = "run",
    exe = ":yarn",
    args = ["run"],
)

# Platform specific commands

export_file(
    name = "node-windows",
    src = "windows/node.exe",
)

export_file(
    name = "node-linux",
    src = "linux/node",
)

export_file(
    name = "node-macos",
    src = "macos/node",
)

command_alias(
    name = "node",
    platform_exe = {
        "windows": ":node-windows",
        "linux": ":node-linux",
        "macos": ":node-macos",
    },
)

name​

Parameters​

Details​

name

Parameters

Details