4.2.4.1 The Command Builder

env.Command(target, sources, "CMD" => command)
# Example
env.Command("user_guide.html", "user_guide.md",
  "CMD" => ["pandoc", "-fmarkdown", "-thtml", "-o${_TARGET}", "${_SOURCES}"],
  "CMD_DESC" => "Generating user guide:")

The Command builder executes a user-defined command in order to produce the desired target file based on the provided source files.

The Command builder supports the following construction variables:

• CMD (required) specifies the command to execute (an array of strings). CMD is expanded for variable references, so the tokens ${_TARGET} and ${_SOURCES} can be used, for example.
• CMD_DESC (optional) specifies the short text description to print when the builder executes. The given description is followed by the target file name.
• CMD_STDOUT (optional) specifies a file to redirect standard output to. CMD_STDOUT is expanded for variable references, so the token ${_TARGET} can be used, for example.