Many times when developing a task, you find the need to run another, existing command. To do this, we have provided you with a DSL you can use to call any command, pass parameters, and even pipe commands together.
The DSL is a sequence of chained methods that will always start with
command() and end with
run method tells the DSL that you are finished chaining methods and that the command should be executed. Here is the simplest possible example:
command( 'version' ) .run();
This runs the
version command and the output will be flushed to the console.
Here are all the possible DSL methods that we'll unpack below:
command( ... ) .params( ... ) .flags( ... ) .append( ... ) .overwrite( ... ) .run( ... );
This is required to be the first method you call. It creates an instance of the
CommandDSL class and returns it. It accepts a single parameter called
name which is the name of the command you wish to run. Type the name exactly as you would in the shell including the namespace, if applicable.
command( 'info' ) .run(); command( 'server start' ) .run();
This method is used to pass parameters to your command. You can pass named or positional parameters to this method, and they will be pass along to the command in the same fashion. There is no need to escape parameter values like you would when running a command manually from the shell.
command( 'cp' ) .params( path='/my/path', newPath='/my/new/path' ) .run();
command( 'cp' ) .params( '/my/path', '/my/new/path' ) .run();
Just like when running a command manually, flags are an optional shortcut for specifying boolean parameters. Pass in each flag as a separate argument. It is not necessary to include the
-- prior to the value, but it will still work.
command( "install" ) .params( 'coldbox' ) .flags( 'force', '!save' ) .run();
You may redirect the output of a command to a file (normally accomplished by
>>) by chaining the
overwrite() methods. These are mutually exclusive.
command( "cat" ) .params( "myFile.txt" ) .append( "myOtherFile.txt" ) .run(); command( "echo" ) .params( "Your new file contents" ) .overwrite( "myFile.txt" ) .run();
Control the working directory that the command runs in if you don't want it to be the current working directory of the shell.
command( "ls" ) .inWorkingDirectory( 'C:/' ) .run();
Piping is a very powerful way to combine multiple commands and is accomplished via the
pipe method. This method expects to receive another
CommandDSL instance. You do not need to call
run() on the nested command. This example is the equivalent to
echo "hello\nworld" | grep lo.
command( "echo" ) .params( "hello#chr( 10) #world" ) .pipe( command( "grep" ) .params( "lo" ) ) .run();
You can have more than one
pipe() method. Each piped command will be called in order, receiving the output from the previous one.
command( "cat" ) .params( "myFile.txt" ) .pipe( command( "grep" ) .params( "searchString" ) ) .pipe( command( "sed" ) .params( "s/find/replace/g" ) ) .pipe( command( "more" ) ) .run();
The above is the equivalent of
cat myFile.txt | grep searchString | sed s/find/replace/g | more
Your DSL should always end with a
run method. This executes the command. By default, the output will be sent to the console, however you can capture it by specifying
var output = command( "echo" ) .params( "My name is Brad" ) .run( returnOutput=true );
If you want to help debug the exact command that is being passed along to the shell for executing, set the
echo parameter to
true and the command will be echoed out prior to execution. The echoed text is not part of what gets returned or piped.
command( "version" ) .run( echo=true );
You may want to manually pipe data into the command (which is the same as passing it as the first parameter. Do so with the
piped parameter to the
command( "touch" ) .run( piped='myFile' );