Command Line Interface

The ScriptEngine command line interface is provided by the se script. The command provides basic help when running it with the -h or --help flag:

> se --help
usage: se [-h] [-V] [--loglevel {debug,info,warning,error,critical}]
          [--nocolor]
          files [files ...]

ScriptEngine command line tool

positional arguments:
  files                 YAML file(s) to read

optional arguments:
  -h, --help            show this help message and exit
  -V, --version         show ScriptEngine version and exit
  --loglevel {debug,info,warning,error,critical}
                        The minimum level of log messages that is displayed.
                        For verbose output, use "debug". For minimal output,
                        use "error" or "critical".
  --nocolor             do not use colored terminal output

Available ScriptEngine tasks: hpc.slurm.sbatch, base.chdir, base.command,
base.context, base.copy, base.echo, base.exit, base.find, base.getenv,
base.include, base.link, base.make_dir, base.move, base.remove,
base.task_timer, base.template, base.time

Using the -V or --version option displays the current ScriptEngine version:

> se --version
0.8.5

One or more scripts can be passed to ScriptEngine as arguments:

> se hello.yml
2021-03-18 09:54:40 INFO [se.cli] Logging configured and started
2021-03-18 09:54:40 INFO [se.task:echo <37f189f217>] Hello, world!
Hello, world!

As seen above, ScriptEngine and ScriptEngine tasks provide information during the run via logging, usually as output to the terminal. The amount of information can be controlled by setting the --loglevel:

> se --loglevel debug hello.yml
2021-03-18 09:58:04 INFO [se.cli] Logging configured and started
2021-03-18 09:58:04 DEBUG [se.cli] Loaded task base.chdir: Chdir from scriptengine.tasks.base.chdir
2021-03-18 09:58:04 DEBUG [se.cli] Loaded task base.command: Command from scriptengine.tasks.base.command
[...]
2021-03-18 09:58:04 DEBUG [se.cli] Loaded task base.time: Time from scriptengine.tasks.base.time
2021-03-18 09:58:04 DEBUG [se.task:echo <aa66c50601>] Created task: Echo: Hello, world!
2021-03-18 09:58:04 INFO [se.task:echo <aa66c50601>] Hello, world!
Hello, world!

> se --loglevel error hello.yml
Hello, world!

Usually, the logging output is colored (not seen in this documentation). This is done on the terminal with ANSI escape codes, but it may be undesired, for example, when the output is stored in a logfile. Hence, colored output can be switched of with the --nocolor argument.

As seen in the output of se --help above, ScriptEngine lists all available task in the current installation. ScriptEngine uses dynamic task loading (see Concepts) and additional task can be installed from Python packages. In the example above, all tasks from the build-in base.* package are available. Furthermore, the hpc.slurm.sbatch task is provided, which comes from the scriptengine-tasks-hpc (go there) Python package.

Note that ScriptEngine task names follow a namespace scheme to prevent name clashes for tasks from different packages.