com.palantir.giraffe.command (Giraffe 0.9.0)

Interface Summary
Interface	Description
Command	Represents an executable path and set of arguments that may be run by an execution system.
Command.Builder	Builds `Command` objects.
CommandFuture	A `ListenableFuture` that provides access to the output and exit status of an asynchronous command.

Class Summary
Class	Description
CommandContext	Provides command-independent information that influences how commands execute.
CommandContext.Builder	Builds `CommandContext` objects.
CommandEnvironment	Describes the environment variables that are present when a `Command` executes.
CommandExitLatch	Listener that shuts down an ExecutionSystem after it's been started and all registered CommandFutures have finished.
CommandResult	Contains the output and exit status of a completed command.
Commands	Static utility methods to create and execute commands.
ExecutionSystem	Provides an interface for command execution and is the factory for command objects.
ExecutionSystems	Factory methods for execution systems.
TerminatedCommand	A simple container for information about terminated commands.

Enum Summary
Enum Description

CommandEnvironment.BaseEnvironment
Defines the target of environment changes.

Enum Summary
Enum	Description
CommandEnvironment.BaseEnvironment	Defines the target of environment changes.

Exception Summary
Exception	Description
ClosedExecutionSystemException	Runtime exception thrown when methods are called on a closed execution system.
CommandException	Runtime exception thrown when a command fails, usually by exiting with a non-zero exit status.
CommandTimeoutException	Checked exception thrown when the timeout for a command is exceeded.
ExecutionSystemAlreadyExistsException	Runtime exception thrown when an attempt is made to create an execution system that already exists.
ExecutionSystemNotFoundException	Runtime exception thrown when an execution system cannot be found.

Package com.palantir.giraffe.command Description

Provides classes and interfaces for local and remote command execution.

Executable commands are represented by Command objects. Each Command is associated with an ExecutionSystem that can execute the command on a local or remote host. Each ExecutionSystem is associated with an ExecutionSystemProvider, which is responsible for creating systems for different hosts using the same connection method, for instance SSH.

Most operations on Commands are defined in Commands. As an example:

 Command ls = Commands.get("ls", "-a", "-l");
 CommandResult result = Commands.execute(ls);

This executes the "ls" command on the local system, returning an object containing the exit code and output.

Local Execution

The local execution system is accessed using the ExecutionSystems.getDefault() method. There is exactly one instance of the local execution system and it cannot be closed. Because the local execution system is created automatically, it does not accept an environment map for configuration. Instead, the following system properties modify the behavior of the system:

Property Description

Property	Description
`giraffe.command.local.envWhitelist`	A comma-separated list of variable names to keep when creating process environments. If set, all environment variables not in this whitelist will be removed from the default environment of new processes. When using Giraffe in certain applications, such as servers or similar long-lived services, the application processes is started with environment variables that should not be visible to command processes and may even prevent these processes from executing correctly. Setting this property allows users to create a well-defined default environment for command execution.

giraffe.command.local.envWhitelist

A comma-separated list of variable names to keep when creating process environments. If set, all environment variables not in this whitelist will be removed from the default environment of new processes.

When using Giraffe in certain applications, such as servers or similar long-lived services, the application processes is started with environment variables that should not be visible to command processes and may even prevent these processes from executing correctly. Setting this property allows users to create a well-defined default environment for command execution.