An abstraction for an external command. More...

Public Member Functions
List< String >	command ()
	Get this command's program and arguments.
File	directory ()
	Get this command's working directory.
String	getErrors ()
	Get the error output collected during command execution.
String	getOutput ()
	Get the output collected during command execution.
void	replaceEnvironmentVariable (String variableName, String value)
	Replace the given variable and its value in the command's environment.
int	run ()
	Execute the command.
int	run (CancelIndicator cancelIndicator)
	Execute the command.
void	setEnvironmentVariable (String variableName, String value)
	Add the given variable and its value to the command's environment.
void	setEnvironmentVariables (Map< String, String > variables)
	Add the given variables and their values to the command's environment.
void	setQuiet ()
	Require this to be quiet, overriding the verbosity specified at construction time.
void	setVerbose ()
	Require this to be verbose, overriding the verbosity specified at construction time.
String	toString ()
	Get a String representation of the stored command.

Static Public Member Functions
static LFCommand	get (final String cmd, final List< String > args)
	Create a LFCommand instance from a given command and argument list in the current working directory.
static LFCommand	get (final String cmd, final List< String > args, boolean quiet)
	Create a LFCommand instance from a given command and argument list in the current working directory.
static LFCommand	get (final String cmd, final List< String > args, boolean quiet, Path dir)
	Create a LFCommand instance from a given command, an argument list and a directory.

Protected Member Functions
	LFCommand (ProcessBuilder pb, boolean quiet)
	Construct an LFCommand that executes the command carried by pb.

Protected Attributes
boolean	didRun = false
ByteArrayOutputStream	errors = new ByteArrayOutputStream()
ByteArrayOutputStream	output = new ByteArrayOutputStream()
ProcessBuilder	processBuilder
boolean	quiet

Detailed Description

An abstraction for an external command.

This is a wrapper around ProcessBuilder which allows for a more convenient usage in our code base.

Constructor & Destructor Documentation

◆ LFCommand()

org.lflang.util.LFCommand.LFCommand	(	ProcessBuilder	pb,
		boolean	quiet )

protected

Construct an LFCommand that executes the command carried by pb.

Member Function Documentation

◆ command()

List< String > org.lflang.util.LFCommand.command ( )

Get this command's program and arguments.

◆ directory()

File org.lflang.util.LFCommand.directory ( )

Get this command's working directory.

◆ get() [1/3]

LFCommand org.lflang.util.LFCommand.get	(	final String	cmd,
		final List< String >	args )

static

Create a LFCommand instance from a given command and argument list in the current working directory.

See also: get

◆ get() [2/3]

LFCommand org.lflang.util.LFCommand.get	(	final String	cmd,
		final List< String >	args,
		boolean	quiet )

static

Create a LFCommand instance from a given command and argument list in the current working directory.

See also: get

◆ get() [3/3]

LFCommand org.lflang.util.LFCommand.get	(	final String	cmd,
		final List< String >	args,
		boolean	quiet,
		Path	dir )

static

Create a LFCommand instance from a given command, an argument list and a directory.

This will check first if the command can actually be found and executed. If the command is not found, null is returned. In order to find the command, different methods are applied in the following order:

1. Check if the given command cmd is an executable file within dir. 2. If the above fails 'which cmd' (or 'where cmd' on Windows) is executed to see if the command is available on the PATH. 3. If both points above fail, a third attempt is started using bash to indirectly execute the command (see below for an explanation).

A bit more context: If the command cannot be found directly, then a second attempt is made using a Bash shell with the –login option, which sources the user's ~/.bash_profile, ~/.bash_login, or ~/.bashrc (whichever is first found) before running the command. This helps to ensure that the user's PATH variable is set according to their usual environment, assuming that they use a bash shell.

More information: Unfortunately, at least on a Mac if you are running within Eclipse, the PATH variable is extremely limited; supposedly, it is given by the default provided in /etc/paths, but at least on my machine, it does not even include directories in that file for some reason. One way to add a directory like /usr/local/bin to the path once-and-for-all is this:

sudo launchctl config user path /usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin

But asking users to do that is not ideal. Hence, we try a more hack-y approach of just trying to execute using a bash shell. Also note that while ProcessBuilder can be configured to use custom environment variables, these variables do not affect the command that is to be executed but merely the environment in which the command executes.

Parameters

cmd	The command
args	A list of arguments to pass to the command
quiet	If true, the commands stdout and stderr will be suppressed
dir	The directory in which the command should be executed

Returns: Returns an LFCommand if the given command could be found or null otherwise.

◆ getErrors()

String org.lflang.util.LFCommand.getErrors ( )

Get the error output collected during command execution.

◆ getOutput()

String org.lflang.util.LFCommand.getOutput ( )

Get the output collected during command execution.

◆ replaceEnvironmentVariable()

void org.lflang.util.LFCommand.replaceEnvironmentVariable	(	String	variableName,
		String	value )

Replace the given variable and its value in the command's environment.

Parameters

variableName	name of the variable to add
value	the variable's value

◆ run() [1/2]

int org.lflang.util.LFCommand.run ( )

Execute the command.

Do not allow user cancellation.

Returns: the process' return code

◆ run() [2/2]

int org.lflang.util.LFCommand.run ( CancelIndicator cancelIndicator )

Execute the command.

Executing a process directly with processBuilder.start() could lead to a deadlock as the subprocess blocks when output or error buffers are full. This method ensures that output and error messages are continuously read and forwards them to the system output and error streams as well as to the output and error streams hold in this class.

If the current operation is cancelled (as indicated by cancelIndicator), the subprocess is destroyed. Output and error streams until that point are still collected.

Parameters

cancelIndicator The indicator of whether the underlying process should be terminated.

Returns: the process' return code

Author: Christian Menard

◆ setEnvironmentVariable()

void org.lflang.util.LFCommand.setEnvironmentVariable	(	String	variableName,
		String	value )

Add the given variable and its value to the command's environment.

Parameters

variableName	name of the variable to add
value	the variable's value

◆ setEnvironmentVariables()

void org.lflang.util.LFCommand.setEnvironmentVariables ( Map< String, String > variables )

Add the given variables and their values to the command's environment.

Parameters

variables A map of variable names and their values

◆ setQuiet()

void org.lflang.util.LFCommand.setQuiet ( )

Require this to be quiet, overriding the verbosity specified at construction time.

◆ setVerbose()

void org.lflang.util.LFCommand.setVerbose ( )

Require this to be verbose, overriding the verbosity specified at construction time.

◆ toString()

String org.lflang.util.LFCommand.toString ( )

Get a String representation of the stored command.

Member Data Documentation

◆ didRun

boolean org.lflang.util.LFCommand.didRun = false

protected

◆ errors

ByteArrayOutputStream org.lflang.util.LFCommand.errors = new ByteArrayOutputStream()

protected

◆ output

ByteArrayOutputStream org.lflang.util.LFCommand.output = new ByteArrayOutputStream()

protected

◆ processBuilder

ProcessBuilder org.lflang.util.LFCommand.processBuilder

protected

◆ quiet

boolean org.lflang.util.LFCommand.quiet

protected

The documentation for this class was generated from the following file:

/Users/runner/work/lingua-franca/lingua-franca/core/src/main/java/org/lflang/util/LFCommand.java

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ LFCommand()

Member Function Documentation

◆ command()

◆ directory()

◆ get() [1/3]

◆ get() [2/3]

◆ get() [3/3]

◆ getErrors()

◆ getOutput()

◆ replaceEnvironmentVariable()

◆ run() [1/2]

◆ run() [2/2]

◆ setEnvironmentVariable()

◆ setEnvironmentVariables()

◆ setQuiet()

◆ setVerbose()

◆ toString()

Member Data Documentation

◆ didRun

◆ errors

◆ output

◆ processBuilder

◆ quiet